I. 問題の背景Points of Argument

(1) マクヴェインは明治初期日本の科学技術発展に重要な役割を果たした。その一つは工部省測量司に観測台設置を計画し、内務省移管後、金星日面通過観測を指揮し、成功させたことである。

--McVean made great achievements for Japan's engineering and science development in early Meiji period (1868-76). As a part of foundation of survey office, he directed to observe the transit of Venus in December 1874 together with John Francis Campbell.

(2) 1872年早々、マクヴェインは測量司の体制と任務を山尾と話し合い、主務の国土測地測量に気象観測や天体観測をも含めることにした。そのための予算措置が必要だったが、明治政府が発足してまもなく、特に工部省は何をどこまでやるのかは不明瞭であり、最初に声を上げて周りを説得したものの理が通るという状態だった。さらにまた、岩倉使節団として実力者官僚が外遊中、留守政府は大きな事業は行わないという約束だったから、山尾にとって大隈を説得して予算を取ってくることは可能だった。

--In January 1872, 3 months after the foundation of the Survey Office under the Public Works, McVean discussed the scope and function of the Survey Office with Yamao Yozo, 2nd Minister of the Works, and emphasized need to start various kinds of observation including meteorology, astronomy and seismology together with geodetic survey of whole national territory. McVean asked Yamao for purchasing the instruments and references necessary for these observation and arrange memorandum for cooperation with the related institutions such as the Royal Observatory and the Scottish Meteorological Association. 

(3) マクヴェイン自身、英国海軍における水路測量の経験から測量点の位置確認のために天体観測に熟練しており、またグリニッジの王立観測台The Royal Observatoryは海軍水路局とにも旧知の友人がいた。ウィリアム･マックスウェルを含む海軍士官Royal Navyに多くの知人がいた。1872年頃からイギリス科学雑誌では1874年12月に金星日面通過現象が起き、アジア・太平洋地域で観測できることが大きな話題となっていた。その観測を測量司が行うことは、気象天体観測を本格的に導入する絶好の機会となるとマクヴェインは考えた。山尾はそれに同意をし、最新測量器機を購入し、それを用いて実施することにし、さらに王立観測台The Royal Observatoryとスコットランド気象協会The Scottish Meteorological Societyへ支援依頼を行った。一次帰国していた1873年9月には、マクヴェインはシャボーを伴って王立観測台で金星日面通過の観測手法の指南を受けたことが、マクヴェイン日記から判明した。

--McVean and Yamao first asked Samejima, an attache of Japan's Foreign Office to the Britain and France, but Samejima was too busy to do that. Soon, McVean decided to get home to purchase the instruments and references, and arrange the memorandum. Yamao permitted McVean to get home in business purpose or a proxy of Yamao in March 1873, and arranged the budget as much as £3,800 for that missions. McVean visited the Royal Observatory to look the instruments there and take instruction how to observe the transit of venus from Simms, and met Alexander Buchan, secretary of the Scottish Meteorological Society. He made all successfully in the Britain, but delayed 5 months the returning due to manufacturing of the instruments.

(4) 測量司は、1874年1月に内務省に移管されてしまい、金星日面通過観測は内務省の事業となったが、これがおそらく日本政府事業として光学器機を使った最初の天体観測であった。金星日面通過の仕組みについて、工部大学校物理学教授エアトンが事後にアジア協会において講演をし、協会誌に寄稿している。マクヴェイン日記に登場するジョン･フランシス･キャンベルJohn Francis Campbellはこの金星日面通過に合わせて来日し、実際、観測を指導しており、これはグリーニッジ王立観測台とスコットランド気象協会からの支援の一環と考えられる。キャンベルは政府要人でありながら気象天体観測とゲール民俗文化研究に類い希な能力を発揮し、この科学的現象に自ら大きな関心を持っていた。さらにまた、イギリスはチャレンジャー号で東アジアでさまざまな観測及び探索を開始ししており、これの活動と無関係ではなかったはずである。スコットランド気象協会事務局長ブキャン、同協会名誉事務局長スチブンソン（北方灯台局のスチブンソン技術事務所、百葉箱の発明者）、英国気象事務所ロバート、チャレンジャー号探検隊長トムソンと同副隊長ティザードらはお互い旧知の間柄だった（英国気象委員会Meteorological Committee）。1875年5月、チャレンジャー号副艦長ティザードと探検隊長トムソンは大和屋敷（内務省地理寮量地課）を訪問し、マクヴェインらに気象観測の指導をした。

--After Okubo Toshimichi established the Home Ofiice in November 1873, he absorbed several engineering departments into his minister. The Survey Office was taken from the Works by the Home Office in January 1874, and new technical officers have taken initiative in the Survey Office when McVean return to the office in May 1874. As they did not admit McVean as Surveyor in Chief, McVean could not direct his office. However, John Francis Campbell, a colleague of Alexander Buchan, came to Japan to help McVean to direct the observation, and McVean urgently asked Ito Hirobumi, temporary Minister of the Home Office as well as Minister of Works permission of execution of the observation. Another cooperation from the Scottish Meteorological Society was made by Prof Wiville Thomson and Tizard, both colleague of Alexander Buchan. They called McVean's Survey Office in May 1875 to give advice on the meteorological observation.

(5) マクヴェインはキャンベルと共同で金星日面通過観測を周到に準備し、当日成功裏に実施したにもかかわらず、シャボーの報告書を除くと、国内外科学史ではまったく知られていない。観測記念写真は「The Far East」掲載された1枚、とマクヴェイン文書の1枚があるが、撮影時間が異なる。そこには、三条実美と伊藤博文の二人、（短時間の大久保利通）、内務省から杉浦譲と室田秀雄、旧幕府海軍の小林一知と荒井郁之助が写っており、内務省にとっては賑々しい行事であったはずである。これがどうして注目されずにきたのか、旧幕臣の内務省技術者による隠蔽があったとしか考えられない。この観測に写真撮影と報道を担当したのがジョン･ブラックで、彼は「好ましからぬ外国人ジャーナリスト」として政府から睨まれており、それが影響したのかも知れない。

--The Observation of the Transit of Venus was made successfully under Campbell's supervising at Gotenyama. McVean and Campbell arranged two observatories and one peepshow hut. Formal observatory was in charge of Henry Scharbau, accepted audiences from government side including Sanjyo Sanetomi, Ito Hirobumi, (Okubo Toshimichi), Arai Ikunosuke, etc. Campbell's observatory or informal observatory was simple ten-like bamboo structure. Three observers watched telescopes respectively. A lot of ordinary audiences watched venus's crossing on the sun disc in the peepshow hut.

II. 既往研究Existing Studies

2-1.原口孝昭氏の「明治7年の金星日面経過観測-観測隊の動向、政府等の対応、派生事項について-」（1997年、科研費報告書）1874Venus Observation by Haraguchi.

はじめに

・海外観測隊の活動に焦点を当てる。彼らが何を目的に、どのようにして日本観測を実施したのか、実施結果はどのような効果をもたらしたか。

［注釈］1874年金星日面通過は、世界の科学者に太陽系の実尺度を決定する絶好の機会と考えられ、世界各国で観測が企画され実施された。明治政府が発足してすぐの日本にはそのような機運はなかった、、と考え、原口氏は内務省地理寮量地局の観測事業については検討していない。

第一章 観測の意義と結果

1. 観測の天文学的意義

(2) 金星日面通過日について：文部省顧問デビッド・マレーが1874年12月3日に同月9日に起きる事象について「文部省雑誌」に紹介した。実際、12月9日の午後2時間ほど、皇居で天覧が行われたといわれる。

・「文部省雑誌 第二十三号」明治7月12月3日発行

今般、文部省御雇い米国人博士デビットモルレー氏、金星試験ノ説ヲ誌し、本省ニ出セリ。因テ、爰ニ記載シ、参考ノ便ニ供ス。明治七年十二月九日金星実測ノ説

・外交史料：米国天文官横浜及長崎ニ於テ金星太陽経過測地ノ為〜

明九日金星試験、御覧被為在候ニ付、御用閑候ハ、午前第十一時三十分ヨリ午後三時迄之間御参内可有之旨、御沙汰候。

依而、此段申進候也。七年十二月八日 宮内卿徳大寺實則

太政大臣 三条実美殿 左大臣 島津久光殿 右大臣 岩倉具視殿 参議 大久保、大隈、大木、寺島、山縣、伊藤、勝、黒田、伊地知

・外交史料：米国天文官横浜及長崎ニ於テ金星太陽経過測地ノ為〜

宮内卿徳大寺實殿 寺島外務卿 明九日金星天覧被為？？午前第十一時三十分より午後第三時迄ニ参内ニ仕旨、御沙汰之趣致承知候。然ルニ、明日ハ魯西亜公使より招待ニ因リ罷越旨

・郵便報知新聞「明治天皇、宮中で御観測」明治七年十二月十二日

去る九日金星天覧の事は、文部科学省御雇い教師ダビット、モルレー氏の奏文によれり。同人金星測量として長崎に赴くあたり金星の経過は天文学士の最も注意する緊要なるものなれば、天覧あらんことを欲し、開拓使五等出仕荒井郁之助及同使御雇デェー氏を推薦して、これを掌らしむることを奏せり。よって本日両人参朝、宮中操練所に於て測量器械御据付に相成り、その現象を叡覧あること午後一時頃より二時間程なり。デェー氏太陽との距離経過の疾徐縷々陳説せり。皇太后宮皇后宮も出御にて、侍臣濱御等に至る迄ことごとくこれを観るを得、おわりて郁之助及び同氏に酒銭を賜わると云う。

［注釈］マクヴェインが1873年9月にグリニッジ王立天文台を訪問した目的が、シムスが行っていた天体観測器機設置工事の視察と、シムスから金星日面通過観測手法の解説を受ける事であった。マレーの報告の前、1873年8月時点で、少なくとも工部省の山尾庸三、マクヴェイン、ジョイナー、工部大学校の教授連は金星日面通過があることは知っていた。

2. 各国の状況

3. 観測結果の一覧

第二章 観測隊の受け入れ検討

1. 日米交渉の発端と観測隊の受け入れ決定まで

・基本資料として公文録明治6年9月外務省ノ部：米国天文官横浜及び長崎ニ於テ金星太陽経過地ノ為器械陸揚仮建物設置方在本邦同国公使ヨリ請求一件

・1873年5月2日米国国務卿代理J.C.ビーダリスから駐日公使C.E.デロング宛て文書「米国海軍による観測の依頼」

・1873年6月30日駐日公使デロングから外務少輔上野景範宛て文書「」

2. 来日する観測隊への対応取り決め

第三章 アメリカ観測隊の動向と政府等の対応

第四章 フランス観測隊の動向と政府等の対応

第五章 メキシコ観測隊の動向と政府等の対応

1.2.3.4.5.

6. 観測後の様子と帰国

・ジャンサンからの経度差測定促し

・マクヴィーンからの依頼

・観測跡地の処理

・アメリカ公使への依頼と観測隊との出会い

・田中不二麿の招待

第六章 日本の観測隊

1. 内務省地理寮の観測隊

(1) 観測隊の編制

・「急遽、独自に観測をすることになった」

・公文書内務省之部六 明治七年十一月」国立公文書館

金星試験之義ニ付伺

當省地理寮ニテ、測量ノ為メ、兼而御買入相成居候望天鏡ヲ用ヒ、相當之場所ヲ撰ミ、測量ノ為メ御雇入相成居候外国人ヲ以、金星試験被仰付度、就テハ、大蔵省、文部省ヘモ此段為心得御達相成候様致度

此旨上申仕候。至急4後指令有之度候也。七年十一月廿四日 内務省伊藤博文 太政大臣三条実美殿

上申之趣聞届、両省ヘ相達候事。明治七年十一月廿五日

(2) メキシコ観測隊への協力依頼

・「ディアス・コバルビアス日本旅行記」

文部省、明治七年十一月二十七日

メキシコ金星観測隊殿

拝啓、わが国内務省は地理寮お雇いのイギリス人ヘンリー・シャボー氏を金星日面経過観測に派遣することを決定したので、本人より本件に関する問い合わせがあれば、何卒御助言を下さるようにお願い申し上げる。敬白。田中不二麿 文部大輔

(3) 内務省地理寮による観測結果

・公文録：明治八年三月

シャーボー申蝶金星測量ノ記

臺十一月廿七日、測量局長ヨリ達書到来、貴下頃英国ヨリ買入相成候天文機械ヲ以テ、金星経過ヲ測量致候儀ヲ被下候。

右等ノ機械ハ、元、右等ノ測量ノ為め製造致候機械ニ無之、又、夫力為買入相成候儀ニハ無之候得共、何分時日既ニ切迫居暫時モ猶豫難相成場合ニ付、支給必要之支度ニ取掛リ、東京近傍ニテ相当ノ場所相導候處、品川近傍ニ有之御殿山ヲ辨理第一ノ場所ト看定候間、同所ニ木材ヲ以テ仮家ヲ造営、第十二月七日落成候ニ付、機械相据候處、土地軟質ニシテ機械水平ニ相据り無候故、直ニ、一ヲ施シ土中ニ木杭ヲ打込ミ、其上ニ機械臺ノ石柱ト相敷候様、其石柱ノ周囲少シ宛テ避テ床ヲ張候様手当致、其翌日ハ、経過観測ニ相用候機械ノ解包修整ニ取掛申候。

兼テ、右等ノ機械差置候、大和邸内七番館ニテハ、経過ノ測量難相成、時辰儀ヲ較準致シ、真正ノ時辰ヲ得候儀不出来ニ致方モ無之候ニ付、右時辰ハ、第十二月九日朝、経過相始候。以前水準器ヲ以テ太陽ノ下規ニ重之高度ヲ測リ、夫ニテ相定候儀ニ有之候。

.............................................Entrance................ Exit.   Duration.

1.クラセン ......... 11時04分48秒   11時29分11秒   3時21分03秒   3時47分55秒

2.チースマン....... 11時04分23秒   11時27分05秒   3時20分26秒   3時47分10秒

3.シャボー ......... 11時03分43秒   11時29分59秒   3時21分27秒   3時47分09秒

［注釈］内務省地理寮の観測は記録が焼失してしまい、いつかの公文書と二次資料から推測するしかない。そのため、この部分は基本的には原口氏の憶測である。「急遽、独自に観測をすることになった」「急いで観測適地を探し観測所を作る計画も練る必要があった」のではなく、工部省測量司時代からの計画であった。そのために1873年9月にマクヴェインとシャボーはグリニッジ天文台で観測手法の指南を受け、器機の購入を行った。マクヴェインの帰国に2週間遅れて、1874年5月24日に器機が到着し、シャボーが6月9日に着任したので、準備時間は十分にあった。しかし、マクヴェインらはそれができなかった。マクヴェイン日記には具体的な理由は書かれていないが、この時期、内務省は卿が目まぐるしく代わり、さらに測量司内は反御雇いグループ（旧大蔵省土木寮からの合流者たち）による主導権争いがあり、大混乱の状態にあったようだ。マクヴェインは、一時帰英中の1873年11月に旧知のシャボーと雇用契約を結び、さらに、同年暮れにはスコットランド気象協会との支援合意を取りつけた。ジョン・フランシス・キャンベルが1874年11月20日に来日し、この観測に参加したのはそのためであろう。

・「それらの矢面に立ったのが地理寮雇いのシャボーはじめ外国人技術者であった。シャボーはイギリス人で、明治6年11月1日に内務省地理寮雇い」ではなく、測量師長のマクヴェインが立案指揮し、シャボーを実施担当者に指名した。木戸と伊藤は短期間大久保の内務卿代理を務めただけで、内務省業務を関わらなかった。内務省が再稼働するのは大久保が再登板する11月28日から。

・「正院を通してメキシコ隊へシャボーを派遣し、観測の助言を得る事にした」。メキシコ隊のコバルビアスも御殿山の観測所を訪れた。「シャボーはメキシコ観測隊の観測所を参考にして観測所を品川に建設した」とあるが、メキシコ観測隊のそれと御殿山のそれとでは全く異なるように見える。「ジョイナーがメキシコ隊の観測を視察することになっていた」ので、これに対し「コバルビアスはジョイナーの来訪を快諾した」とあるが、ジョイナーは御殿山観測所のキャンベルグループの方にいた[Campbell1876]。

・ジョン･キャンベルの動向は原口氏が集めた資料の中には描かれていない。

2. 海軍観象台での観測

3. 皇居での観測

・参議への参内通知

「明九日金星試験、御覧被為在候ニ付、御用閑候ハ、、、午前第十一時三十分ヨリ午後三時迄之間御参内可有之旨、御沙汰候」七年十二月八日。宮内卿大徳寺實則

三条実美、島津久光、岩倉具視、大久保利通、大隈重信、大木、寺島、山縣、伊藤、勝、黒田、伊地知、

4. 新聞報道

・明治7年12月12日郵便報知新聞「明治天皇、宮中で御観測」

デビッド。モルレーの奏聞、開拓使五等出仕荒井郁之助及び同使御雇教師デユー氏を推薦して、これを掌らしむることを奏せり。宮中訓練所において測量器械御据付に相成り、その現象を叡覧あること午後一時頃より二時間ほどなり。

III. 基本資料と新資料Fundamental Source and Newly Found Reference

3-1.既知の資料Well Known Reference

(1) 国立公文書館所蔵公文録内務省之部National Archives

・公文書内務省之部六 明治七年十一月金星試験之義ニ付伺

當省地理寮ニテ、測量ノ為メ、兼而御買入相成居候望天鏡ヲ用ヒ、相當之場所ヲ撰ミ、測量ノ為メ御雇入相成居候外国人ヲ以、金星試験被仰付度、就テハ、大蔵省、文部省ヘモ此段為心得御達相成候様致度

此旨上申仕候。至急4後指令有之度候也。七年十一月廿四日 内務省伊藤博文 太政大臣三条実美殿

上申之趣聞届、両省ヘ相達候事。明治七年十一月廿五日

・公文録文部省、明治七年十一月二十七日メキシコ金星観測隊殿

拝啓、わが国内務省は地理寮お雇いのイギリス人ヘンリー・シャボー氏を金星日面経過観測に派遣することを決定したので、本人より本件に関する問い合わせがあれば、何卒御助言を下さるようにお願い申し上げる。敬白。田中不二麿 文部大輔

・公文録内務省 明治八年三月シャーボー申蝶金星測量ノ記

※内務省は1873年11月29日に大久保利通を初代卿として発足したが、大久保が佐賀の乱鎮圧のため東京を留守した期間は木戸、清国出張の時期には伊藤が代理卿を勤め、1874年11月28日に内務卿に復職した。従って、金星日面通過観測の準備時期は伊藤が、観測直近からは大久保が管轄した事になる。この間、地理寮は杉浦譲が統括したが、大久保ともともに本務の方に忙しく、測量地図、気象観測、天体観測などについては何も積極的な施策を行わず、無策であった。大蔵省土木寮から合流した小林一知らが測量司（8月30日以降、量地課）のイニシアチブを取っていたと思われる。

※1875年7月に内務省庁舎が全焼し、公文書や地図などが焼失したので、工部省測量司時代から内務省所蔵文書はほとんどない。偶然というか奇跡的に庁舎の外にあったもの（大川通久が保管していた草稿文、大和屋敷の旧工部省官舎に置いてあった気象観測器機とパルミエーリ地震計など）は残った。

(2) 東京日々新聞などの新聞記事Articles in Japanese Newspapers.

--12月12日

・内務省，先に金星経過測量の命を奉じ，地理寮お雇い測量師，英人シャボーをしてこれに担当せしめ，仮に場を品川旧御殿山の南橋に設け，測大器三箇を置き，本日内務大亟兼地理頭杉浦譲，少内史兼地理寮五等出仕塚本明毅，地理寮五等出仕村田文夫，同六等出仕室田秀雄，少技監水野行敏，測量師長マクビーン等これを監視す。シャボー及び測量役英人クレーソン，チースメン三人各測器に当たり，英人スチュアルト時振儀を按じ，金星の太陽に経入および経過するその初中末三度を測り，かつ英人ブラックをして写真鏡をもってこれを写さしむ。三條太政大臣，伊藤参議両閣下もまたこれに来臨せられ，工部少亟以下もこれを会観す。その経過時刻および高度等は成算の後，精しくこれを公布すべし。

※これはブラックが『ファー・イースト』誌に「金星日面通過について」というもっと詳細な記事を書いており、それからの翻訳であろう。ただ、臨席した人物名はこちらの方が多いが、どちらにも大久保内務卿が来席したとは書かれていない。それについては別項で考察。当時の公文書や新聞記事では、公権力が官吏あるいは民間人に指示して何かをやらせたという書き方がされているので、注意が必要。内務省執行部からこの事業に対する積極的な動きはなく、1873年1月にマクヴェインは山尾工部省少輔と新しく購入した測量器機でこの観測をやることを決め、同年3月頃にグリニッジ天文台に協力依頼をし、同年9月にシャボーとともに同天文台で観測手法の指南を受けた。一時帰国したマクヴェインは、内務省に測量師長としての身分保障を求めたが、なしのつぶてのようだった。身分不確定のまま、日本人反乱分子のいる測量司をマクヴェインは束ねることはできず、金星日面通過観測ができるか逡巡していた。そこに、11月20日になってマクヴェインを訪ねてジョン・フランシス・キャンベルが東京にやってきたことにより、マクヴェインは内務省に金星日面通過観測（理由は「金星測量」のため！）の実施申請を行うことに決めた。科学者でもある英国政府官僚のキャンベルはこのために日本にやってきており、またマクヴェインの父親とは知り合いだった。キャンベルがマクヴェインに来日をどのように伝えていたのかは、両者の記録はなにも書かれておらず分からない。二人は東京中心部で最適な観測所を探しだし、マクヴェインは11月24日に伊藤内務卿に実施申請を行った。御殿山には隣接して2箇所の観測所が設けられ、一つは購入してきた3台の測量器機を設置した公式観測所、もう一つはキャンベルの3台の器機による観測所、さらに「のぞき小屋Peeping Show」が作られた。この全体を統括したのがマクヴェインで、公式観測所はシャボーを担当者とした。計6台の望遠鏡（測量器機も含む）で6箇所の通過観測データが得られたことになる。「のぞき小屋」を含む、観測所設営については下記のキャンベルの記述を参照。

(3)『ディアス・コバルビアス日本旅行記』（大垣貴志郎・坂東省次共訳、1983年5月） ISBN 4-8419-0208-2". Francisco Díaz Covarrubias, Astronómica Mexicana al Japón: para observar el tránsito del planeta Venus por el disco del sol el 8 de diciembre de 1874

・メキシコ観測隊を指揮していたコバルビアスの記録で、日本の科学史研究では大変よく知られている。

第六章 日本人の参加

pp.105.

その頃、文部大輔田中不二麿閣下より書簡を受領した。それは、日本政府が金星の日面経過観測にヘンリー・シャボー氏を派遣する事に決定したため、本人からの願い出があった時には、観測上必要な助言を与えて欲しいという内容のものであった。

公文書を自分自身で持参したシャボー氏と面談した後、田中閣下には当然のことながら一切の資料、助言、説明を与える事を惜しまないと回答した。同書簡は補遺九に収録されている。

シャボー氏はイギリスの水路技師で、大日本帝国地図作成のために同政府が設立した委員会［内務省地理寮］の委員長の立場にあった。彼は、自分の専門分野及び測量学の分野では恐らく非常に卓越した人物であったが、天文学の経験はと言えば皆無に等しかった。周知の事であるが、ヨーロッパでは技術者の専門化は我が国より進んでいる。ヨーロッパでは測量学と天文学の両学間の適用が地図製作上不可欠である時でさえも、測量学者はあくまで測量学者として、同様に天文学者は天文学者としてのみ参加するのだ。このため、地図製作の実施に当たっては、普通、さまざまな専門分野の科学者の協力が必要となる。

シャボー氏は私を訪問して、政府の任命を受けた者であると自己紹介した時、以前にイギリス海軍省で水路技師を勤めていたと付け加えた。同時に、持ち前の素直さで天体観測の経験が皆無であることを腹蔵もなく言明された。そして、任命された仕事に対しては、最善を尽くして成就したいから、まず観測所の地方時間、次いで地理上の位置を決定するうえに手早な方法について理論と実践の両面で教えて欲しいと申し出た。

私は大喜びで経験上最良のものと思われる助言を与え、実際の仕事で模範を垂れて、練習少なくしてより正しく使用可能な方法を教示した。それにもかかわらず、短時間にケースに合わせて的確に天文学上の初歩的知識を得、必要な腕前をみがくことはいかに困難なことであるか隠し立てはしなかった。

またシャボー氏の設問に応えて、政府直轄の地理寮使用の機械を調査する目的で、首都に出かけた。イギリス人技師が地理寮の世人を遂行する上でどんな方法をとればいいかは、彼らがどんな機械を使っているかを見れば私の意見はほほ決まるに違いないと思ったからである。首都では私が目にした機械一式はイギリス製で相当完全な機械であった。性能と大きさではわれわれ機械と比べて見劣りするが、反対に仕上がりの点は完璧な製品であり、入手して間もない全くの新品であった。その中には、子午儀、経緯儀、天頂儀および性能の良いクロノメーターが二台あった。一台は天体時間測定用、あとの一台は平均時間測定用であった。当初からシャボー氏にと思って構想を練っていた計画にそって予備観測と日面経過観測を実施するには、機械は十分にそろっていた。機械の調整を終えた後、予定の計画を進めた。

シャボー氏は熱心かつ活発に働いた。われわれの観測所と同じ建設方法を取り入れて、横浜と東京の間にある品川の近くに、臨時観測所の建設を開始した。しかし残念なことに、建設工事が完了する前に、機械を首都から観測所まで移動させるさいにクロノメーターを破損してしまった。シャボー氏によれば、破損度が大きく、短期間で、観測所の地方時間を測定することも、日面経過観測を行うことも望みがなくなった。

p.119

12月の初め頃、神奈川県令［中島信行］から日本語で書かれた書簡を受理した。同封の英語訳によれば、地理寮に勤務するイギリス人技師ジョイナー氏が政府より金星の日面経過観測の任命を受けたため、私の観測所を訪れるという内容のものであった。補遺十一に明らかなとおり、ジョイナー氏を歓待する旨を回答したが、本人は観測所に現れなかった。彼はその後、同政府より前述のシャボー氏計画の観測助手として派遣された者と考えられる。

※コバルビアスは、シャボーを「大日本帝国地図作成の委員会の［内務省地理寮］の委員長」であると理解しているが、この時期、地理寮にはそのような委員会はなかった。関連するのは地理寮測量師長という地位で、マクヴェインが勤めていた。おそらくシャボーは自分を大きく見せるために、モッタのであろう。ジョン・キャンベルが来日し、観測の指導をしてくれることになり、マクヴェインは金星観測の実施を地理寮正の杉浦に申し出た。11月24日付け伊藤内務卿（大久保出張中の代理内務卿、当日まで）から太政大臣宛に、観測事業について文部省と大蔵省に周知願いたいとの伺いが出ており、その関係で田中文部大輔からコバルビアス宛に協力依頼の手紙が発信された。メキシコ観測隊は文部省の許可を得て実施しており、それとの協力関係を築くためであったと思われる。

・シャボーはリューベックで生まれ、イギリスに帰化したが、婦人と子供たちフランスに居住しており［McVean Letter: 1873］、少なくともフランス語はできたと思われる。シャボーの経歴は別項を参照していただくことにして、彼は師長マクヴェインに指名され、金星日面通過観測の主任担当を勤めたにすぎない。マクヴェインはシャボーを連れて、1873年9月にグリニッジ天文台を訪問し、ジェームス・シムスから金星日面通過の仕組みと観測手法の指南を受けていた。

・基本的にマクヴェインの指揮で外国人技師全員（ハーディとマッカーサーを除く）が参加することになっていた。御殿山観測所には、シャボーが担当する公式観測所とキャンベルの私的観測所の二つを設け、それぞれに三台の望遠鏡を設置した。チースマンは20年近くの測量経験を持ち、クラセンとスチュワートは10年の経験を持っており、望遠鏡で何をはかればいいのか瞬時に理解でき、的確に操作できたはずである。1873年9月にグリニッジ天文台でシムスから金星日面通過の仕組みと観測手法の指南を受けたことを、シャボーはコバルビアスに語っていない。観測手法は難しいものではなく、裸眼で色ガラスを介して金星が太陽面を通過する時刻をかることであるが、それに加え、この現象を印画紙に鮮明に投影させて写真撮影することにしていた。ただ、金星日面通過観測データによっていったい何を知ることが（太陽直径の計算他）できるのかはよく分からなかったと思われる。それについては、マクヴェインとキャンベルは工部大学校のエアトン教授と情報交換をしており、エアトンは1875年1月号『ファー・イースト』誌と『アジア協会日本支部雑誌』に懇切丁寧な距離計算方法の解説を投稿した（別項参照）。

※キャンベルは太陽光記録計を発明したことを考えると、太陽のイメージをスクリーンに写し、また印画紙に映し出すことなど簡単にできたのであろう。キャンベルは多くの人に観てもらおうと「見世物小屋Peep Show」を設営し、マクヴェイン婦人はそれを見たと日記に述べている。シャボーはキャンベルの存在を無視し、コバルビアスに一言も語っていない。憶測であるが、キャンベルが参画したことにより、シャボーとマクヴェインの仲は決定的に悪くなったのかもしれない。

3-2. 新資料Newly Found Reference

(1) The Nature, 1873

･May 8: We learn from Sirius that the Russian Government has devoted 70,000 roubles to the observation of the Transit of Venus, and is to send out twenty-four expeditions to various parts of the world.

･May 8: A very interesting publication is the " Memoir of the Founding and Progress of the U.S. Naval Observatory," at Washington, prepared by Prof. J. E. Nourse, by order of Rear-Admiral B. F. Sands, the present Superintendent of the observatory. The large pamphlet gives details of the history of the observatory from the first attempt in 1810 to move the American Government to take steps to establish a meridian for America, so as to make that Country independent of the meridians of Greenwich and Paris, down to the present time, when by the liberality of the Government and the zeal and knowledge of American astronomers and meteorologists, it has become one of the most efficient observatories in the world. The present observatory was founded in 1842, and the first superintendent was the late Commander M. F. Maury, whose successors have been Capt. J. M. Gilliss, Rear-Admiral C. H. Davis, and Rear- Admiral B. F. Sands. In their attempts to render their observations, astronomical, meteorological, and magnetic, as thorough and wide as possible, the officials have been well backed by the American Government, the result being, as we have said, that the observatory is perhaps the most efficient institution of the kind in the world, both with regard to the higher aims and the practical results of the sciences with which it is connected.

   Every year, almost every month, as the readers of our "Notes "must have seen, are new ramifications being developed, and new means of greater efficiency being added. For the purpose of circulating accurate time, the observatory is connected with all the telegraphic offices in the United States, and every day at 12 o'clock, the exact time is by this means made known through out the country. At present, as we noted some time ago, there is being constructed for the observatory by Messrs. Clark, of Cambridge port, at a cost of 50,000 dollars, a refracting telescope of the largest size ; and as we also noted several months since, preparations on the most liberal scale are being made for observing the forthcoming Transit of Venus.

［和訳］

※5月8日、私たちはロシア政府が金星日面数か観測のために7万ルーブルを用意し、世界各地に24の観測隊を派遣することをシリウスから知った。

※5月8日、アメリカ合衆国から出た『海軍観測台の創設と発展の回想録』はとても興味深い出版物で、現アメリカ合衆国海軍観測台長官であるサンド中尉の指示により、ナース教授が作成したものである。（中略）ケンブリッジ･ポートのクラーク氏によって5万ドルを費やして、来たるべき金星日面通過観測のために巨大な観測台が建設中である。

･June 12: JEREMIAH HORKOX

   IF national glory can ever be connected with a natural phenomenon, the transit of Venus over the sun's disc may be said to bring peculiar distinction to England. It is in a manner inscribed upon one of the most brilliant pages of our naval history ; it led to some of the most remarkable discoveries for which mankind is indebted to our geographical enterprise, and made the renown of our most famous navigator. A hundred and thirty years be fore Cook, the phenomenon itself was, for the first time in human history, accurately observed in a corner of England, by an English youth, self-taught, and provided with few of the appliances of scientific research. Now that the spectacle, so striking in itself, so sublime in the infrequent regularity of its recurrence, so important as the key to numerous astronomical problems, is again attracting the attention of civilised mankind, now that the expanse of ocean from Honolulu to Kerguelen's Land is about to be dotted with watchers from the other side of the earth, the occasion appears favourable for recalling the memory of the original observer, Jeremiah Horrox, curate of Hoole, near Preston, in his day one of the most insignificant of English hamlets.

June 19: M. Wolf has taken a series ot magnificent photographs with Leon Foucault's siderostat during the last partial eclipse. He was then testing the photographic process which he intends using in Japan on the next Transit of Venus. The Japan Embassy was present at the operations and exhibited a great deal of truly scientific curiosity.

［和訳］

※6月12日、金星の太陽面通過は自然の驚異なる現象である。（後略）

※6月19日、M.ウルフ氏は、先の日食時にレオン･フーコーのシデロスタットで非常に貴重な写真を撮影した。彼はこの写真による過程を、日本で次の金星日面通過に用いようと試験を繰り返している。日本大使館は現在機能しており、大きな科学的関心を示している。

･Sept. 25:

   The Council communicated with his Grace the Duke of Argyll, the Secretary of State for India, upon the subject, with the result explained in the following letter :—"India Office, February 28, 1873.

"Sir, — With reference to my letter of the 13th of December last, relative to an observation in India of the Transit of the planet Venus in December 1874, I am directed to state, for the information of the Council of the British Association for the Advancement of Science, that the Secretary of State for India in Council, having reconsidered this matter, and looking to the number of existing burdens on the revenues of India, and to the fact that the selection of any station in that country was not originally contemplated for 'eye-observations' of the transit, has determined to sanction only the expenditure (356/. ~s. bd.) necessary for the purchase and packing of a Photolieliograph, and any further outlay that may be requisite for the adaptation of such instruments as may be now in India available for the purpose of the proposed observation.

   "The Duke of Argyll in Council has been led to sanction thus much of the scheme proposed by Lieut. Colonel Tennant, in consequence of the recommendation submitted by the Astronomer Royal in favour of the use of photography for an observation of the transit at some place in Northern India.

"I am, Sir, Your obedient Servant,

(Signed) " Herman Merivale."

"William B. Carpenter, Esq., British Association."

［和訳］

※委員会は、次の手紙に説明された結果に関して、インド省大臣のアーガイル公爵と連絡を取り合った。『1873年2月28日インド省』1874年12月に起きる金星日面通過のインド観測に関する昨年12月13日の私の手紙に関して、英国科学発展協会委員会（中略）北インドで金星日面通過観測に写真を用いることに了解を求める。

［解説］

1.遅くとも1873年5月には世界各国が金星日面通過観測に意欲を示し、少なくともイギリス、ロシア、アメリカ合衆国が大々的観測隊を組織しようとしていたことがわかる。

2.1873年6月の時点で、イギリス観測隊は金星日面通過を写真撮影しようと駐英日本大使館にコンタクトをとったことがわかる。レオン･フーコーは地球の自転を「フーコーの振り子」でしめした人物。ウルフの所属は不明。

3.アーガイル公ジョージ･キャンベルは1868年〜1873年にインド省大臣を務めており、もともと自然科学に並々ならぬ関心を持っていたことから、インド植民地でも金星日面通過観測を計画し、実施した。義兄のジョン･キャンベルは公私にわたってジョージと親しく、お互いに情報交換をしていたことは間違いなく、ジョンが日本での観測を終え、イギリスに戻ると、ジョージから義兄が日本で大変お世話になったという謝辞が寄せられた。マクヴェインのアイオナの牧師館用地はジョンの父親（第七代アーガイル公）から借りたものだった

(2) Articles in The Japan Weekly Mail.

--The Japan Weekly Mail, November 28, 1874. TRANSIT OF THE PLANET VENUS OVER THE SUN’S DISC ON DEC. 8th-9th 1874.‘

On December 8th-9th of the present year n. transit of the planet Venus over the Sun's disc will take place, which have the Sun above their horizon during the occurrence of the phenomenon. It will, therefor, be visible at Yokohama. on December 9th. The Venus, at her inferior conjunction, as she moves in her orbit round the Sun, passing between the Earth and the Sun, has less latitude or distance fl'0lI1,ill6 Ecliptic than the Sun’s semi-diameter, she will be at a less distance from the Sun's centre than such semi-diameter, and will therefore be within the Sun’s disc. In this ease the planet, being between the Earth and Sun, its dark side being turned towards the f'ormer, will appear projected upon the Sun’s disc as a black round spot. The apparent motion of the planet being theii- retrograde, it will appear to move across the discsussion East to West, in a line sensibly parallel to the Ecliptic.’ ‘ v

Such a plienomeuoii is culled a transit; and as it can only happen in the case oi‘ planets whose orbits are included within that of the Earth, and which therefor from time to time pass between the 'Earth and the Sun, it is limited to the interior planets Mercury and Venus.

If the plane of the orbit of Venus coincided with the plane of the Eeliptic, the planet would cross the Sun’s disc every time that it passed through its interior of junction ; but as liei' orbit is inclined to the Ecliptic at an angle of 3° 23', she sometimes passes above the Sun and sometimes below it, coiiseqiieiitly the transits oi" Venus iire oi? rare occurrence, and they are separated by very unequal interviils of 8, 122, 8, 105, 8, 122 &c., years.

The transit of Venus was first observed by Iiorrox in 1639, and was announced to the world in the celebrated pamphlet “ Venus in. Sole visa.” The two last occurred in 1761 and 1769 ; the two-next. will be in 187-L and 1882, after which none will take place till the year 2004.

［注釈］

※1874年11月28日、12月8日から9日にかけて金星日面通過が起きることになっている。

--The Weekly Mail, December 5, 1874.Dr. David Murray, the adviser to the Education Department, accompanied by Mr. Hatakeyama, the Director of the Imperial College at Yedo, have been inspecting the College and chief schools of Osaka. They are on their way to Nagasaki, to join the United States Transit of Venus party.—Hiogo Nears.

--The Japan Weekly Mail, December 5, 1874. THE TRANSIT OF VENUS. (Times of the Gib April).

In the course of tho next four or five months, several Government expeditions, very carefully prepared and equipped, will start from the Royal Observatory at Greenwich for remote parts of tho globe, in order to observe tho transit, or passage across the sun's face, of the planet Venus, early in December next. In preparation for this enterprise, a stall’ of astronomers and photographers, composed of officers of the Naval and Military services, with a spilinking of civilians, have been working at t.ho Observatory for some months, under the guidance of Sir Geroge Airy and his assistants, practising themselves in the complicated observations and other dalitato processes! which will be required of them, and upon the proper accomplishment of which so much that is important in astronomy depends. Few subjects of u soiontillc kind have excited so much public interest and discussion as this one of the approaching Transmit. In itsolf, tltogrand problem of the accurato detertiiiiialioii of our distance from the sun, and thence of tho distances of tho planetary bodies and of those fow of the fixed stars whose remoteness can bc gauged at all by any means yet known to science, must have attactions for every intelligent mind. The interest and curiosity naturally appertaining to the question have been, lllo|'l'0Yt'I" not n little stimulated on this occasion by_t,ho articles aml letters on the general subject of tho. Transit which have ht-on published during the last your in our own coluiuu! and clscwlicre. Enough. certainly, has been told to whet the appetite ofthe public for the furtlicr details. For the information, therefore, of those of Our readers who cannot go to Greenwich and learn these things for tlietnsslvos, we purpose giving some account of the energetic and complete arrangements which England and other countries are no\v inaliiuz for the observation of one of the moat rare mid scieiitillcully valuable of celestial phenomena.'

Probably most persons are an are by this time that of tho three or four different methods by which the Transit may bn observed the one known as llelisle's is that on which England, in common with the |ua_jorit_v of the other nations taking part in tho work. will place chief reliance on the coming 0L'.l!lBi0I]. Duo regard will be given to the use of the Halloyan method as well at t-hoso points where the whole Transit will be \'islhlt', as will bc Iltc. case nt. all of our southern stations; but the Astronomer Royal's (.‘llOlt'tl of stations has mainly been made on Ibo basis of their suitability for the method of Dolisle. Briefly and popularly, this consists in the accurate determination of the iutervnl of time which elnpscs between the moment when some instantaneous phase of tho 'l‘i-nnsii is seen from one point on tho earth, and that at which the corresponding phase is seen from another point far (li.~lunt from the first, a necessary condition being that this time-interval shall be as great as circumstances will admit of. The two phases most suitable for observation are,-firstly, t,‘-e upparout outry or “ ingress" of the planet on the sun's surface, and, secondly, her departure or “ egress" from it; and the critical moments to be seized arr, in lin flrst case, t-hose at which, from dill'orcnt ll-‘lll0|l‘, the planet's hinder edge, or “following limb," is seen exactly in contact with tho sun's edge on one side; and, in the It'COlld case. that at which, from other stations, her advanced edge, or “ preceding limb," is similarly seen in contact on the opposite side. In other words, they are the first and last moments, respectively, at which, from the several points, the whole disc of the plant-t is scou just within tho sun's rim. A crown-piece laid on n. largo round table, toucliing its edge, first on the left hand and then on the right, will servo to illuslrntc the above phases, which aro called thoso of “interior contact " at ingress and egress respectively.

That the reader may now understand aotiiethiug of the ('OII(llli\\lIS which govern the choice of stations, let him contcive a plane to piss through the'oentres of the earth and sun, nnd through the centre of Venus at the moment when she first arrives within u cortical surface similarly imagined to envelupo the circuiufcrcucos of the-. earth and sun. This plane will evidently cut. tho edge of tho illuminated half of the earth in two points di:imetrit'_-tlly apart. And since Venus, moving faster than the earth, crosses tho sun's fact: from cast to west, it is also evilent that nu observer plncrd at the eastern extremity of this diameter will witm-ss hcr iiign-.<s sooner than he would from any other point on the globe ; while an ub:sei'\‘er at the opposite or western and will sensibly be tho last to see it — neglecting, for the sake of brevity, the slight change llll»l‘O(lll<‘0tl by the earth's axial rotation, and by her own and \'onus's p|'Opcr motions in the interval, none of which, however, may be overlooltcd in practice. The one would see the interior contact at ingress “most tt00Ol6l'DiiCd;" the other the same phase “ most retarded."

［訳Translation］

(3) Articles in the Far East.

・The Far East, Tokei, December 11th, 1874. 

--The transit of Venus, so long, so anxiously, and so universally looked forward to by the astronomers and scientific men of all civilised nations, made its appearance true to its time, and has become a thing of the past. In Yedo and Yokohama the day was happily everything that could be desired, and as our readers have already been told of the observations made at Yokohama and its neighbourhood, by various observers, so we now relate that Japan did not allow the occasion to pass without having her observers at work in Tokei.

--Unfortunately she made no preparations until within the last fortnight. Magnificent instruments of the necessary kind had, however, just been received from home, for survey purposes. They are of the very best kind made for such uses ; and though probably not so powerful as would be especially prepared for such important observations as that to which they were applied yesterday, yet they were sufficiently so to make observations which will be of great value, as the contribution of Japan to the congress of scientists, to whom will be submitted all the observations taken everywhere, for the grand calculations of the distance between the Earth and the Sun.

--Although so short a time was left in which to make preparations, Mr. McVean, the head of the Survey Department, whilst officially notifying the government of the great disadvantages they would labour under, as compared with those who had taken time by the forelock and got everything in order long before, yet set to work with great energy. Mr.Scharbuo, who has been engaged for upwards of twenty years in the Meteorological Department of the British Admiralty, and who has been specially engaged for similar duties in Japan, also exerted himself, and, assisted by Messrs Klasen and Cheeseman of the Survey Department, managed to get a temporary observatory erected, good solid granite foundation blocks placed, and the necessary instruments levelled and well adjusted on them. The Japanese officers were equally anxious to forward the operations, and thus evinced the true spirit in which Japan seeks to take her place among the nations. It was too late to have any proper apparatus fixed for photographing the transit, but two days before, Mr. Black having been requested to give his aid in this way, had cameras on the ground, and took the Sun at intervals of from 2½ to 10 minutes, taking, in all, seventy images.

The instruments used were a 12-inch theodolite and a transit instrument. 

［和訳Translation］

・金星日面通過、それはすべての文明国の天文学者と科学者が本当に首を長くして待ってきたもので、今そのときがやってきた。江戸と横浜では、幸運なことにその日はすべてにおいて好条件に恵まれていた。本誌の読者は、その観測者によって観測が横浜とその近傍で成功裏に行われたことを知っていることであろう。それで、日本は東京においても専従の観測者がいなくとも、この好機を見過ごすことがなかったことを述べる。

・残念なことに、二週間前までは何の準備もしていなかった。しかしながら、そのために必要な立派な装置が測量のためにイギリスから届いていた。それらはその目的のために製造された最高のものだったが、今回の重要な観測のためには十分に強力なものではなかった。昨日彼らはそれらを用いて観測を成功させ、地球と太陽の距離の計算のためのデータを科学者に届けることになろう。

・準備のために時間は限られていたが、測量師長マクヴェイン氏は政府に公式にそのことを告げ、大変な努力の末にすべてを整えた。シャボー氏はイギリス海軍気象局に20年以上にわたって勤め、日本でも同じような任務に従事し、そしてクラセン氏とチースマン氏の手伝いを得て実施した。臨時の観測所は難い花崗岩の礎石の上に建てられ、その上に必要な装置が水平になるように調整された。日本人職員も同じように熱心に操作に当たり、そして日本は世界の国々の中で立派にできることを示した。しかしながら、写真撮影のための専用の装置を用意する時間がなかったが、観測の二日前、ブラック氏に協力が求められ、そしてカメラを地面に置き、2分半から10分の間隔で太陽を撮影し、全部で70枚のイメージを取ることが出来た。

［解説Account］

--"The Far East" magazine was published by Black, who wrote this article. There are some mistakes, firstly the observation of the Transit of Venus was planned by Yamao and McVean in early 1873 when McVean got home to purchase survey and observation instruments. McVean, together with Schabau were instructed how to observe the Venus by James Simms of the Royal Observatory in September 1873. Secondly, Scharbau was Lubeck born surveyor and cartographer, and has been hired by several surveying institutions such as the Ordinance Survey Department and Hydrographic Survey Department during 1850s and 1860s. He came to Japan by McVean's invitation.

・『ファー･イースト』誌はブラックの出版物であり、この記事も彼が執筆した。ブラックの経歴は<WHo's Who for McVean>を参照願う。いくつかの間違いがあり、第一は金星日面通過観測の準備に関して、マクヴェインは山尾と相談し1873年2月には観測実施をすべく、一次帰国に際して、そのための器機購入（測量器機であるが、天体観測にも使える高性能のもの）と関係機関への協力依頼を行った。1873年9月に王立観象台でシムスから観測手法の指南を受けたことがマクヴェイン日記から分かる。

・「シャボー氏はイギリス海軍気象局に20年以上にわたって勤め」とは誤りで、英国海事博物館資料室文書によれば、リューベックに生まれ、どのような専門教育を受けたのかは不明であるが、30歳頃にイギリスに渡り、最初、陸軍陸地測量局に契約雇用されスコットランド南部の測量に従事した。その後、1860年頃海軍水路測量局に移り、ヘブリディーズ地方の測量に従事し、そこでマクヴェインやチースマンと一緒に働いた。詳細は＜McVean's Who's Who＞を参照。

［解説Account］

--Front row from the right, McVean (with béret), Murata Fumio (2nd Commissioner of Survey Office), Sugiura Yuzuru (with fur hat, 1st Commissioner of Survey Office),  Sanjo Sanetomi (with top hat, Prime Minister), [space], Kobayashi Kazutomo (surveyor of the Survey Office, former Shogunate Navy), Murota Hideo (with fur hut), Arai Ikunosuke (1st Commissioner of the Hokkaido Development Agency, former Shogunate Navy), (Ootsuka?). Ito Hirobumi  just left this site or does not come yet.

・前列右から、マクヴェイン（測量師長）、村田文夫（量地課正）、杉浦譲（ファーハット、地理寮頭）、三条実美（トップハット、太政大臣）、［スペース］、小林一知（量地課測量師、旧幕府海軍）、室田秀雄（ファーハット、量地課職員）、荒井郁之助（開拓使技官、旧幕府海軍）、（塚本）。室田は大物二人（旧幕府海軍箱館戦争組、大蔵省土木寮からの合流組）の間に割って入って、「まあ、まあ、まあ、よくいらっしゃいました」と言ってるのだろうか。下のマクヴェイン所蔵写真に比べると、影が長く伸びているのがわかるので、こちらの方が撮影時刻が後である。伊藤博文と大久保利通は帰ってしまった（revised in August 23, 2019）。

・Far East, 1875 vol.6-7

THE Transit was observed in Tokei from at temporary observatory erected at Shinagawa, a suburb of Yedo. The observers were Messes. Scharbau, Klasen and Cheeseman, and the instruments used were the admirable ones ordered by Mr. McVean, the head of the Survey Department, when at home. The day was everything that could be desired ; but, of course, it is impossible yet to give the results. We give a photograph of the temporary shed, as it will serve to commemorate a deservedly memorable occasion. The central figure, in front of the edifice, is Sanjo Sanetomi, Dajo Daijin (Prime Minister) of Japan. The picture of the Shinagnwa Railway Bridge was taken from the same spot, so that it will serve to give an idea to our readers of the locality of the observatory.

・Far East, 1875 vol.6-7

THE Transit was observed in Tokei from at temporary observatory erected at Shinagawa, a suburb of Yedo. The observers were Messes. Scharbau, Klasen and Cheeseman, and the instruments used were the admirable ones ordered by Mr. McVean, the head of the Survey Department, when at home. The day was everything that could be desired ; but, of course, it is impossible yet to give the results. We give a photograph of the temporary shed, as it will serve to commemorate a deservedly memorable occasion. The central figure, in front of the edifice, is Sanjo Sanetomi, Dajo Daijin (Prime Minister) of Japan. The picture of the Shinagnwa Railway Bridge was taken from the same spot, so that it will serve to give an idea to our readers of the locality of the observatory.

［和訳Translation］

・江戸郊外の品川に設置された臨時観測所から金星日面通過観測が行われた。観測者は、シャボー、クラセン、チースマンの3人で、測量師長のマクヴェインが英国本国で購入してきた最高の装置で行われた。観測日はそのためにすべての点に置いて恵まれていたが、しかし、当然のことながら観測結果が良好であったのかはまだよく判明しない。本誌では臨時観測所の写真を載せ、この記念すべき大事件を記録することにしよう。屋敷（?小屋）の前の中央の人物は、三条実美太政大臣である。品川の鉄道橋写真も、この場所から撮影されたので、読者にはこの場所がどこか分かっていただけるであろう。

［解説Account］

--The observation site was a hill of southern Tokyo, Shinagawa, called "Gotenyama." To lay wew railway line between Yokohama and Shinbashi, Gotenyama was cut into two, west portion and east portion. The Todaido Highway overcrossed he railway line by a bridge called Yatsuyama Bashi. The observatory was placed on the east portion, it is now Shinagawa Girls' School site.

・御殿山は横浜新橋間鉄道敷設のために掘削され、東西に分断されてしまった。北側には八ツ山という高台、南側に権現山があり、その東側斜面下に東海道が通る。東海道の切り通し箇所には八ツ山橋が架けられた。金星日面通過観測所は、御殿山の東部分に置かれ、現在は品川女子学院指揮となっている。

(4) Articles in Journal of Asiatic Society of Japan

・Ayrton's Account on the Transit of Venus, ASIATIC SOCIETY OF JAPAN. The Far East 1875 vol.6-7.工部大学校教授エアトンによる金星日面通過観測に関する考察

※全文はV.参考文献を参照。

From a Special Reporter of the "Tokei Journal" revised by Professor Ayrton.

ON Tuesday evening Professor Ayrton delivered a lecture on the Transit of Venus to the members of this Society and their friends, who filled the large room of the Grand Hotel and who numbered about 130. The meeting was presided over by Mr. Good-win, who was supported by Sir Harry Parkes, the Russian Minister, Mr. Russell Robertson, Captain Oesterreicher, and other influential members. In introducing the lecture; the President expressed his lively satisfaction at seeing so numerous and intelligent an assemblage pre-sent to hear the approaching phenomenon discussec•and briefly explained. He presumed that all his hearers felt interested in the Transit of Venus, although if they were asked defiffitely, to explain why they felt interested, and why they ought to be so, many might find it extremely difficult to adduce sufficient reasons. Yet all of them knew that learned men in all parts of' the world attached great importance to the accurate observation of the event, that the Governments of various countries had appointed stations and fitted out expeditions to watch the events which were about to take place Well, why this expense was gone to, and this trouble taken, Professor Ayrton had kindly undertaken to explain, and he now had only to ask him to fulfil his kind promise. We were glad to see that the beaten path usually followed by the Asiatic Society of reading a written paper was departed from. Not only was Professor Ayrton's lecture not written, and therefore not read, but in addition no notes of any kind were used by that gentleman during the course of the evening. We feel sure that such extempore speaking carries with it a force and earnestness almost impossible to obtain with a

［和訳Translation］

・火曜日の夕方、エアトン教授はこの協会会員と彼の友人に対して、金星日面通過に関して講義を行い、グランドホテルの大部屋が満員になるほど、約130人の来場者があった。

(5) Ookubo's Diary大久保利通日記

明治七（1874）年十二月九日

今朝伊地知子入来林子入来九字より

皇居に参昇清国随行官員一同然

御学問所謁見被 仰付清国談判ニ付一同太儀之段

勅語有之難有御禮奉申上候終る内待所参拝神酒弊物ヲ賜ル控所ニ退く綿三巻紅白縮緬四匹宮内省山岡ヨリ拝領被 仰付随員ニモ夫々賜リ候

十一字此退 出税所吉原同車川村氏ニ参 金星経過一覧イタシ候

［解説Account］

・大久保は台湾事件事後の解決のために清国に渡り、イギリスとフランスの公使の協力を得ながら首尾よく補償条約をまとめ上げた。その功績を天皇からたたえられ、12月9日午前中に宮中で報償が与えられた。大久保は先の11月28日に内務卿に復職しており、この日は彼にとって人生最良の一日で、短い文面からでも上機嫌であったことがわかる。その後、主税と吉原を伴って車に乗って川村のところに行った。そして、「金星経過一覧イタシ候」と続く。原口氏の研究に拠れば、当日、皇居内でも観測所が設けられ皇族と参議が招待されていたらしい。しかし、内務省も御殿山に観測所を開設し、参議や官僚を御殿山観測所に招待しており、『ジャパン・ウィークリー・メール』や『ファー・イースト』が報じるように、実際、参議の三条実美や伊藤博文はこちらの方に臨席した。この写真には大久保の姿は写ってはおらず、では皇居内観測所に行ったのであろうか。しかし、税所と吉原と同じ車に乗って川村邸まで行き、その後金星経過を一覧したとなっており、皇居内の移動ではなかったことがわかる。すると御殿山の観測所に向かったと考える方が自然である。従って、御殿山の内務省の金星日面通過観測所に短時間でも大久保はいたと考えられる。おそらく、記念写真撮影時刻には間に合わなかっただけだったのであろう。もう一つ不思議な点があり、それは御殿山観測所写真に小林一知と荒井郁之助が写っていることである。原口氏の研究では荒井は皇居内学問所に設けられた望遠鏡を操作することになっていた。その彼が、御殿山観測所の記念写真に写っているということは、皇居内観測はなんらかの理由でキャンセルされたのか、早めに切り上げてこちらにきたのではないかと考えられる（revised in August 23, 2019）。

(6) John Francis Campbell＋John Reddie Black's Account on Observation of Venus Transit in Japan.

・本書の中で、キャンベルは自らの金星日面通過観測と内務省のそれの準備から結果までを克明に記録している。彼はなんとなんと日本に観測装置3台を持って来ていた!!!(added in July 19, 2019)。この『ジャパン・ガゼット』は『ファー・イースト』と同じ、ジョン・レディ・ブラックの出版であり、彼がキャンベルから助言を得て執筆したと考えられる。ブラックは英国海軍に数年間勤めたことがあり、科学知識も相当にあった。ブラックは『ジャパン･ガゼット』を内務省の許可を得て出版したが、政府批判の文言が書くこともあり、そのために廃刊処分に追い込まれた。この出版物を所蔵している日本の図書館はどこだろうか。本出版物については最近英語の研究書がでたので、ご参照を。

"MY CIRCULAR NOTES.Extracts from Journal, Letters Send Home, Geological and Other Notes, Written while Travelling Westwards round the World, From July 6, 1874 to July 5, 1875 by J. F. Campbell, London, MACMILLA.N AND CO. 1876.

The Japan Gazette.

"The Transit of Venus, so long, so anxiously, and so universally looked forward to by the astronomers and scientific men of all civilized nations, made its appearancetrue to its time, and has become a thing of the past. In Yedo and Yokohama the day was happily everything that could be desired, and as our readers have already been told of the observations successfully made at Yokohama and its neighbourhood, by various observers, so we now relate that Japan did not allow the occasion to pass without having her observers at work at Tokei.

" Unfortunately she made no preparations until within the last fortnight. Magnificent instruments of the necessary kind had, however, just been received from home, for survey purposes. They are of the very best kind made for such uses ; and though probably not quite so powerful as would be especially prepared for such important observations as that to which they were applied yesterday, yet they wore sufficiently so to make observations which will be of great value, as the contribution of Japan to the congress of scientists, to whom will be submitted all the observations taken every where, for the grand calculations of the distance between the Earth and the Sun.

" Although so short a time was left in which to make preparations, Mr. McVean, the head of the Survey Department, whilst officially notifying the Government of the great disadvantages they would labour under, as compared with those who had taken time by the forelock and got everything in order long before, yet set to work with great energy. Mr. Scharboo, who has been engaged for upwards of twenty years in the Meteorological Department of the British Admiralty, and who has been specially engaged for similar duties in Japan, also exerted himself, and, assisted by Messrs. Klasen and Cheeseman of the Survey Department, managed to get a temporary observatory erected, good solid granite foundation blocks placed, and the necessary instruments levelled and well adjusted on them. The Japanese officers were equally anxious to forward the operations, and thus evinced the true spirit in which Japan seeks to take her place among the nations. It was too late to have any proper apparatus fixed for photographing the transit, but two days before, Mr. Black having been requested to give his aid in this way, had cameras on the ground, and took the sun at intervals of from two-and-a-half to ten minutes, taking, in all, seventy images.

" The instruments used were a twelve-inch theodolite and a transit instrument; at which were, respectively, Messrs. Cheeseman, Scharboo, and Klasen. Mr. B. Stewart attended at the chronometer. The observations taken by them were confined to the exact moments of contact of the outer and inner edges, both in the passage of the planet on and off the snn's disc ; this date we hope to be able to present in a few days.

" A most admirable picture of the transit, throughout its entire course, was thrown by means of a telescope on a sheet of double elephant paper, stuck on a Japanese door. This was suggested and entirely carried out throughout the day by Mr. Campbell of May, who, as a traveller round the world, happens, to have been staying with Mr. McVean in Tokei for some days. The telescope was on a stand placed on a box about six feet high, and the door with the white paper was in a little dark chamber about six feet square, made of a framework of bamboo covered with black paper. The box standing in front of the chamber, the eye-piece of the tele scope was admitted into the latter through a slit in the covering, and being properly focussed, a beautiful image of the sun, fully three feet in diameter, was thrown upon the white paper, and the planet, when fully on, was like a round black water about an inch in diameter. At the first moment of contact Mr. McVean, Mr. Joyner, Mr. Campbell, and Mr. Mee, the latter a native gentleman connected with the Survey Department, were watching; and they saw the first contact some time before it was shown by the instruments, thus evidencing the advantage of size in such observations. The appearance of the planet as shown by the instruments was only about one-tenth or one-twelfth the diameter as shown on the paper. It was a fortunate thing for all visitors that Mr. Campbell was present, and had the forethought on the previous day to suggest the erection of this little " peep-show," as he humorously called it. To the numerous Japanese visitors who during the day arrived on the ground it gave at once a clear conception of what was going on, without the trouble of applying their eye to any instruments what ever ; although most of those who did present themselves were permitted to see what was to be seen with the more scientific appliances.

"His Majesty the Mikado, who was expected, did not visit the observatory ; but His Highness Sanjo Daijin arrived about noon, and was evidently very much interested in the proceedings. As Mr. Mozer (who had kindly accompanied Mr. Black, to help in the photographic operations) was about to take a picture of the observatory for the December number of the Far East, His Highness very kindly seated himself in front, with a number of other Japanese gentlemen and others connected with the day's doings, and the picture was taken.

" Throughout the day, Mr. Mozer prepared the whole of the plates, while Mr. Black exposed them and took the time, The images are very small ; but, if enlarged, from their con tinuity throughout the entire day, from the commencement to the close, they should be valuable, as showing precisely the course taken by the planet."

［訳］ジャパン･ガセット「金星日面通過」

・金星日面通過、それはすべての文明国の天文学者と科学者が本当に首を長くして待ってきたもので、今そのときがやってきた。江戸と横浜では、幸運なことにその日はすべてにおいて好条件に恵まれていた。本誌の読者は、その観測者によって観測が横浜とその近傍で成功裏に行われたことを知っていることであろう。それで、日本は東京に専従の観測者がいなくとも、この好機を見過ごすことがなかったことを述べる。

・不幸なことに、日本は2週間前まで何の準備もしていなかった。しかしながら、この観測に必要なすばらしい機器が測量のためにイギリスから到着していた。これらはその目的のために製造された中でも最良のものだった。そして、この重大な観測のため強力なものではないが、十分価値あるものだった。そして、日本は太陽と地球の間の距離を計算するために科学者の集団に大きな貢献をすることになるであろう。

・準備のための時間はとても短かったが、測量師長のマクヴェインは、周到に準備を進めてきた他の組織に比べると、大変遅れをとっていることを日本政府に伝え、大変な労力で仕事を成し遂げた。英国海軍の気象局[?水路測量局の間違い]に20年以上も勤めていたシャボー氏は、日本でも同様な業務に従事し、測量局のクラセン氏、チースマン氏によって支援され、仮設の観測所を大理石の基礎ブロックの上に建設し、その上に必要な装置を水平に設置した。日本人官吏たちも操作に大変興味を持ち、世界各国の事業に参加しようという意気込みを示していた。金星通過を撮影するために取り付けるべき装置を手に入れることは間に合わなかったが、ブラック氏は支援の要請に応えてくれ、彼のカメラを地面に置いてくれた。そして、太陽を2時半から10分おきの間隔で撮影し、全部で70枚の写真を撮ってくれた。

・用いた機器は12インチのテオドライト一台とトランシット一台で、それぞれ、チースマン、シャボー、クラセン氏が操作した。スチュワート氏はクロノメーターを担当した。彼らが関わった観測は金星が太陽面に入る時と出るときの外端と内端の精確な接触時刻を確定することが出来た。この日時は数日中に公表できるであろう。

・通過の過程の中でもっとも賞賛すべき写真は、二重エレファント版の紙の上にテレスコープによって撮影され、そして日本式ドアに貼り出された。この観測は、その日、アイラのキャンベルの提案によって実施された。キャンベルは、世界旅行の途中に、偶然に数日間、マクヴェイン氏のところに滞在していた。（おそらく、偶然を装わないと、キャンベルはここにいることができなかった）テレスコープは、約6フィートの高さの台座の上に設置されたスタンドに取り付けられ、白色の紙が貼られたドアが約6フィート四方の小さな暗室に置かれ、暗室は竹で骨組みを作り外側を黒色の紙で覆ったものであった。暗室の前に立つ箱に、テレスコープの接眼レンズが覆いのついた隙間を通して通され、そして適正にフォーカスが合わせられた。直径３フィートの太陽の美しいイメージが白色紙の上に映し出され、それが完全になったときには、まるで直径約1インチの物体が黒色の水に浮いているようだった。接触の最初の時刻に、マクヴェイン氏、ジョイナー氏、キャンベル氏、測量局勤務の日本人のミエ氏が観測し、彼らは機器によって示される少し前に最初の接触を見て、この観測でサイズの長所を確認した。

・機器によって示される惑星の外観は、白紙の上に約十分の一、あるいは十二分の一直径となった。全ての訪問客にとって、キャンベル氏がいてくれ、そしてこの小さな「のぞき見」小屋を建設することを提案してくれたことは、大変幸運なことであった。その日、大勢の日本人がここにやってきて、この観測は何が起きているのか、科学的な機器を通して容易に見ることができたであろう。

・ミカドの観測所への来訪は予定されていたが、実現しなかった。しかし、三条実美太政大臣は正午頃にやってきて、観測に大変関心を示された。（ブラック氏の写真撮影を手伝ってくれた）モーサー氏は『ファー・イースト』誌の12月号のために観測所の写真を撮ることになっていたので、他の関係日本人紳士たちとともに太政大臣は彼（写真機）の前にお座りになり、写真に納められた。

・その日、モーサー氏はすべてのプレートを用意し、一方、ブラック氏はそれらを露光し、時間を計った。イメージはとても小さかったが、しかし、はじめからおわりまでのものを拡大すれば、それらは惑星の通過を精確に見せてくれることになる。 日本は今、鉄道と電信の敷設、陸地測量から、そして各種観測、蒸気船、新聞、国債を始めようとしている。人間の最も巧妙な装置が全世界の最良の商業環境の一つに植え付けられ、全ての偉大な力により観覧された。彼らは政治研究の最も大きな関心の一つとなり、外部からながめることのできる悲劇と喜劇の奇妙な混合である。

［解説Account］

・『ファー・イースト』発行者であり記者のブラックの名前が記事の中に登場しており、これは当時16歳になるブラックの息子であろうか（例の快楽亭ブラック）。モーサーはオーストリア人写真家で、当時22歳だった。マクヴェイン紳士録を参照。

(7) Campbell's Letter to J dated December 11, 1874.Jに宛てた手紙

My dear J.,

--You have been a great deal in my head of late, and your letter of the 12th October reached me to-day. You know the proverb. I thought of wanderings in the back slums of London (1845), of a queer green Dutch glass bought for a shilling, collared and carried off, and the despairing cry of the vendor," Oh, do tell me what is that I have sold ! "I thought of all these things, because I, bitten by you, and of that same kin, have spent fortunes in rubbish since I came here. I have just deposited a pile of boxes at the shipper's office, and home will go a miscellaneous lot as ever you saw. Nothing that I can write will ever give you the wildest notion of this country. It has been famous for curios for centuries, and now it is famous for fine modern work of all its own kinds of art. But it has gone through a great revolution.

----On the 9th I joined the surveyors, and rigged up some of my optical dodges to see the transit. I had an old telescope, with a paper umbrella at one end, and a bower of bamboos and black paper at the other. Within the bower was a screen of white paper, and thereon was an image of the sun about two-and-a-half feet wide, with the star on it as big as a sixpence. The minister of public works and the prime minister came into my bower, and the Mikado was coming. But some Yankees rigged him a telescope in his garden, and he sat there all day instead.

--By another of my dodges, Mr. Black, the Delane of Yedo, took about fifty pictures of the transit [of venus], and I am to have an imperial gift of lacquer for my services I hear. What I care most about was that I saw the whole transit, beginning, middle, and end, to perfection. But it was queer to be shut up in a paper bower with all these little great men who made the revolution which unmade so much, and gave so many curios to the market and to me at cheap rates. Sir Harry Parkes offered to-day to present me to the Mikado. I declined, because I want to start and see the public of his country, and the interior of it.

--If I get out of it some fortnight hence, the result will go home in another letter, and you may see that by applying at home.

Give my love to all friends who care for

J. F. C, The Globe-trotter and Vagrant.

［和訳］

・10月12日付けのあなたの手紙が今日私のところに着きました。あなたはこの格言を知っているだろうか。ロンドンの裏小路のスラムの驚異を思い出した。風変わりな緑色オランダガラス、、後略

・12月9日、私は測量士たちに合流し、金星日面通過を見るために私のいくつかの光学機器をなんとか備え付けた。私は一台の古い望遠鏡を持ってきており、片手に紙傘を、もう一方の手で黒紙を持った。小屋の中には白紙のスクリーンがあり、そこに約2.5フィート幅の太陽のイメージと6ペンスコインほどの大きさの星とともに映し出された。工部卿と太政大臣が私の小屋にやってきて、ミカドもくることになっていた。しかし、数人のヤンキーが彼の庭園でテレスコープを操作し、彼はそこに一日中座っていた。（やっぱり皇居でアメリカ人による観測があり、ミカドはそちらにいたらしい） もう一つ付け足すなら、ブラック紙は金星日面通過の写真を約50枚撮影し、そして、私の奉仕に対して漆器の皇室褒美があると聞いた。私が最も注意したのは自分の目で金星日面通過を見ることであり、最初、途中、最後まで完全に成し遂げることができた。しかし、すべてのこれらの小さな巨人と一緒に紙の小屋に座ることはまことに奇妙なことだった。これらの人たちはできそうもない革命を起こし、少ない出費で社会と私に多くの貴重なものをもたらした。パークス氏は今日私にミカドに謁見するように申し出てくれたが、私はこの国の公衆と内陸を見たいのだといって断った。

［解説Account］

・キャンベルは『ガリバー旅行記』を大変気に入っていた。

(8) Campbell's letter dated December 11  in "My Circular Notes". キャンベルの12月11日付け日記

No. XXXI. Yokohama, Japan", December 11th, 1874.

E., my Dear,

--I got your letter at the tail of your grandmother's of October 4th this morning. So here are my thanks, and a story. I passed through a village some time ago, which was all hung with rows of lanterns, on which was the device *,* I asked what it meant, and was told that it meant the story of three heads. Once on a time a tyrant daimio ordered one of his retainers, who was a good and faithful man, to be beheaded. That was done, and the head was put into a boiling pot. But the retainer had a faithful friend and comrade who cut off the tyrant's head, and put it into the pot with the other. Then the two heads fought a terrible fight in the pot, and the retainer's head was wellnigh vanquished by the tyrant's knob. Then the faithful friend cut off his own head, and dropped it into the pot, and the two overcame the tyrant. The dots I suppose are the heads, and their tails pigtails, and the border is the pot I presume. The whole is the crest of somebody I believe, and the illumination was a festival. This is the queerest country I ever was in.

--Letters of this date will tell you what I have to say when they get to your grandmother. I dine with Sir Harry Parkes to-morrow, and next day go back to Yedo or Tokio, thence to start for Kioto, 300 miles off, by an inland road, called the Nakasendo.

--Oh, that I could speak, what fun I should have in this queer country ! I send some dresses home, which will astonish you, My love especially to A , of the wandering tastes, and to your stay-at-home mother, and the rest of you.

J. F. C,

Story-teller to the Family.

*******************************

Log.—Extended notes.—December 9.—Transit of Venus.—

The Sun's image on the screen measured roughly, Om. 6350.the star, 0m. 0200. According to various watches and records in my tent, the following were the times :

....................................................Entrance............................ Exit.   Duration.

1. McVean ......... 11h.07' 00"   11h.32' 25"     25' 25" .... 3h.23' 3*   3h.51' 04"    28' 01"   4h.44' 04"

2. Joyner .......... 11h.02' 30"   11h.26' 38"     24' 08" .... 3h.16' 47"  3h.45' 30"    28' 43"   4h.43' 00"

3. Mee ............. 11h.09' 30"   11h.39' 00"     29' 30"..... 3h.24' 32"  3h.47' 45"    23' 13"   4h.48' 15"

4. Scharbau .......................................  25 16 .................................. 25 42

参考（内務省報告書）最初外規接着 同内規接着 最後内規接着 同外規接着

1.クラセン ......... 11時04分48秒   11時29分11秒   3時21分03秒   3時47分55秒

2.チースマン....... 11時04分23秒   11時27分05秒   3時20分26秒   3時47分10秒

3.シャボー ......... 11時03分43秒   11時29分59秒   3時21分27秒   3時47分09秒

［和訳］

・スクリーンに映し出された太陽の姿は、およそ6350、0200である。私のいたテントにおける各種の時計と記録によれば、次がその時間である。

［解題］

・観測者は、マクヴェイン、ジョイナー、ミエ、シャボーの四名であった。ミエは地理寮英語通訳と思われる。この表は時間を表しており、左から第一接触時刻、第二次接触時刻、第一と第二の時刻の差（すなわち金星が左太陽輪郭線を通過するまでの時間）、金星が右太陽輪郭線に接触した時刻、金星が右太陽輪郭線を通過した時刻、右輪郭線に入ってから出るまでの時間、最後は、金星が左太陽輪郭線に接触してから右太陽輪郭線から出るまでの時間。観測者と数値は、「シャーボー申蝶金星測量ノ記」（1875年2月24日付けマクヴェイン発杉浦地理頭宛文書）のものとは異なるが、それがいったいなぜなのかまったく不明。「私のテント」に「三フィートの望遠鏡を」を設置して、内務省地理寮観測所とは別に行っていた事になる。すなわち、御殿山にはシャボー班とマクヴェイン班があり、キャンベルは全体を指導していたと思われる。別のところではキャンベルは「ヤンキー一人も観測していた」と述べているので、開拓使のデイが来ていたのかも知れない。

*******************************

--The manner of taking these observations was to say the least of it remarkable. An old telescope on a stand was borrowed from somebody. On the 8th, we drove off with it in three jinrikishas, and on the way to the hill from which we were to " Survey the Venus," I bought a black paper umbrella. The end of the glass was poked through, and the tube was made fast to the bamboo stick, with a string. A big deal box was pressed into the service, and on it this novel astronomical instrument was placed. There was no screw for moving the eye-piece. By dint of some trouble the sun was shot, and an image cast on a sheet of paper. The thing could be made to work, but the light was so strong outside that we had to keep the image small, and bright.

［和訳］

・これらの観測のやり方はまったくもって特筆すべきものだった。スタンドの付いた望遠鏡は誰からか借りたものだった。12月8日、私たちは三台の人力車に分乗し、丘の上に登り、そこから金星測量を行った。私は黒色の紙傘を買った。ガラスの端に小さな穴を開け、竹の杖から即座に筒を作り、そして糸を取り付けた。結構大きな箱をこの仕事のために代用し［台座のことか］、その上にこの斬新な天体観測装置を設置した。接眼レンズを動かすスクリューはなかった。このようなやり方でも、太陽光が入り込み、イメージが紙面に写った。うまく行きそうだったが、しかし外部の光が強すぎたので、私たちはイメージを明るくするためにイメージを小さくした。

--A Japanese carpenter was got and by the aid of interpreters and pencils he was told what to do. No work man could be more "gleg at the uptak." In a very short time a bundle of bamboos appeared with a lot of black paper; and a dark chamber was set up in a trice, exactly where it was wanted. Inside of it, a Japanese sliding door was propped up, with a large sheet of white paper, and thereon the sun's image was cast. The contriver of this popular observatory took charge of the end of the telescope, and managed after some practice to keep the image on the board and in tolerable focus. But he could not see clearly and work the glass, and move the screen as the sun moved ; nor could he read the time. Therefore friends came into the camera obscura, and crouched there watching the board, watch in hand. The hill was near the railway and trains shook it ; the place was crowded and people tramped about and shook the ground. The box got severe knocks; once somebody overturned the umbrella telescope.

［和訳］

・日本人大工を雇い、通訳と鉛筆の助けを借りて、やって欲しいことを伝えた。これ以上迅速にやれる作業員はいなかった。短時間の内で、多量の束の竹が黒紙とともに持ってこられ、瞬く間に欲しいと思っていた暗室ができあがった。その中に、大きな白紙が貼られた日本式引き戸を持たれ掛けさせ、その上に太陽のイメージが投影された。この簡便な観測所の考案者は望遠鏡の端っこを担当し、［太陽の］イメージを大きくかつ精確なフォーカスに保つようにある程度の練習を行った。しかし、彼は鮮明に見ることができず、ガラスを使い［色ガラス？眼鏡？］、太陽の動きに合わせてスクリーンを動かした。さらに、彼は時計を読むことができなかった。そこで、友人たちがカメラ・オブスキュラの中に入ってきて、そこでしゃがんでボードを眺めた。この丘は線路に近く、汽車が振動を伝えた。この場所は人で一杯になり、人が歩くことで地面に震動が起きた。箱に人が激しくぶつかり、一度は傘下の望遠鏡を倒してしまった。

--The hand which held it got tired, and shook ; and more than all the atmosphere over this low, marshy, hot plain was boiling. We could see the waves of air passing over the sun's disc in various directions making the edge of the disc of light bend and quiver, and wave. I had photographed the sun often, and we saw what a difficult job it must be for the observers at the legitimate telescopes. They shot sitting, we were taking flying shots. But our sun was so big and pale that we could all look him in the face without blinking and with both eyes, and so we saw remarkably well, all things considered.

［和訳］

・操作をしている手が疲れ、揺れてしまった。低く、じめじめし、暑い平原の向こう側は蒸していた。私たちは太陽のディスク面を空気流がさまざまな方向に流れるのを見ることができた。私は頻繁に太陽を写真に撮り、私たちは最も道理にかなった望遠鏡で観測者にとってとても困難な仕事であると思った。彼らは座って写真を撮り、私たちは飛ぶような速さで写真を撮った。しかし、私たちの太陽はとても大きく、おぼろんでいたので、私たちみんながそれを瞬きせずに両眼で見ることができた。私たちは思った通りのことをうまくやり遂げることができた。

--At the expected time the observers began to count one— two—three—and we inside the paper house began to quake and shake with keenness. " I see it," said one. " No." " Yes." " Yes." " YES." There it was beyond a doubt, a growing stalk first and then a mouthful bitten out of the cake. " Take the time ! " " By George we saw it long before the other fellows," whispered one. Then the counting outside stopped, and everybody gasped ; and then began the palaver. Meantime I was watching for the only thing that I hoped to see, and presently I saw a ring of light outside the star, and knew that there was a clear atmosphere about the opaque planet.

［和訳］

・予定されていた時間に、観測者は１，２，３とカウントを始め、紙の家に入った私たちは膝を震わせた。「さあ、見るよ！」と誰かがいった。「ノー」、「イエス」、「イエス」、「イエス」。間違いなく、その時は近づいており、そしてケーキの端っこがほんのちょっとかじられた。「時間を取って！」、「本当に、やっとその時がきた！」と誰かがささやいた。その後、外部のカウンティングが止み、そして皆が息をのんだ。そして、から騒ぎが始まった。その間、私はながらくみたいと思っていたこの一つのことを、今、星の外側に光のリングをそのやっと見ることができ、この不明瞭な惑星について鮮明な環境があることを知った。

--We had seen the dark stalk grow, as the atmosphere of Venus approached the Sun, we saw irregularity on the junction of the two curves, now I saw the bright ring outside of the advancing circle, and I was content. Better men were taking times, to calculate withal ; I had got my fact packed in the paper box all safe. There is an atmosphere about Venus, which refracts light and behaves as a clear glass bottle filled with any opaque matter does when in the same position. On that fact those who will may build theories. "No sabe." I don't know whether people live up there, but the atmosphere makes it more probable.

［和訳］

・金星の環境が太陽に近づくとともに、私たちは暗いストークが成長するのを目にした。私たちは二つの曲線の交差が不規則であることを見て、そして、今、私は前進する円周の外側に明るいリングを見て、満足した。より良い人物が時間を計り、その間に計算した。

--The photographic dodge was often used while striving to make solar scales for the Light-House Commission, and for divers purposes. See vol. ii., Frost and Fire. It served well to record the progress of an eclipse. A photographic camera is stopped till the sun's light is greatly reduced. It is aimed at the sun, focussed for parallel rays, and fixed. A prepared plate is placed, and the cover of the lens is moved and replaced as swiftly as possible.

--After waiting till the earth has turned the camera an angular distance sufficient to clear the sun's apparent diameter, the cap is again moved and replaced. Two images are thus impressed, and ten or a dozen can be made on the same plate, even of wet collodion, thus—oooooooooooo.

［和訳］

・写真撮影に仲間は大変慣れていた。

--From the 5th to the 15th, according to the Nautical Almanac, the sun's apparent diameter was 32' 24". It was found practically that images taken at intervals of two minutes touched. Therefore the pictures were taken by Mr. Black and his helps at longer intervals. The negatives were taken with an old ricketty camera, eked out with Japanese boxes to lengthen the focus and enlarge the image. This was the plan which I used July 15th, 1860, to produce the specimen plate which was carried abroad this time in hopes of getting some record of the transit made by this rude plan somewhere.

--Mr. Black's negatives showed the star on the sun. I have yet to see how the prints turned out. As the old saw says—

"Don Fernando cannot do more than he can do."

［和訳］

・12月5日から15日まで、「ナチュナル・アルマナック」によれば、太陽の明確な直径は。これは1860年7月15日に試験体を作成するために用いた計画であった。ブラックの雇った現地人は太陽面の星を見せた。私はできてくるプリントをまだ見ていない。老人曰く「ドン･フェルナンドは彼がやれる以上のことはできない」。

--December 10.—McVean, Scharboo, and I, went to Yokohama, and called at the Mexican observatory. Senior Diez showed photographs taken with a good telescope and camera as large and sharp as those which are taken at Kew with a similar instrument. As the Japanese Government only asked their officers to photograph the transit three days before the event, it was impossible to fit cameras to telescopes, so my makeshift was the only resource at Tokio. The Mexican observer during the transit cast an image from his large telescope on a sheet of paper, and admitted a large number of Japanese spectators, who saw and were greatly interested.

［和訳］

・12月10日、マクヴェイン、シャボーと私は横浜に行って、メキシコ観測所を訪問した。セニョール・ディアスは彼られ撮影した写真を見せてくれた。それはキュー天文台が備えている同じような装置で撮影したものと同じように大きく鮮明であった。日本政府はこの出来事の三日前に金星日面通過の撮影を許可したので、カメラを望遠鏡に取り付けることができなかった。私の間に合わせのものは東京で唯一のものだった。メキシコ観測隊は、彼らの大型の望遠鏡でイメージを大きな白紙に投影することが出来た。そこには大勢の日本人観客が訪れ、かれは大変な関心を示した。

--My audience included the prime minister and the minister of public works. What a lot of beef and beer we did consume at the Grand Hotel when we had done with the stars. As the Chinaman says, " Can do." There be things that mortal men can do, even with very imperfect helps. According to my philosophy, it is best to do them as well as possible by honest effort, and leave the " Cannot." There is an atmosphere about Venus ; and, so far as I can see, there is none about the moon, but " No sabe." I never shall know whether either or neither is inhabited. One side of the vexed question may seem more probable to men who have lungs which need air, but there, may be creatures that live in sunlight on the moon who would be drowned in air as men are drowned in the sea. " No sabe." Therefore, let us feed grossly on beef and beer, and suffer ignorance, philosophically, like Britons and Don Fernando.

［和訳］

・私たちの観覧者の中には太政大臣と工部省大臣がいた。私たちこの惑星の観測を成功させると、グランド･ホテルで牛肉とビールをたらふく楽しんだ。チャイナマンが言うように、「キャン･ドゥ」であった。

［解題］

3-3. マクヴェイン文書

 1874年8月頃からマクヴェインは家族日記執筆を止め、代わりにマリーが書くようになった。マクヴェインは業務日誌は別につけていた。

-1) McVean Diary

・McVean Diary 1873, Wednesday 24 Sep.

-(c) Went to Kensington Museum – Tomita out saw Taketa - afterwards went to Charlton with S to see the instruments in course of construction by T & S Mr Simms shewed us an apparatus for practising observing the transit of Venus

［和訳］

・9月24日、ケンジントン博物館に出かけ、冨田は外出中だったが、武田には会った。其の後、Sを伴ってチャールトンにいって、そこでT&S社が設置工事を行っている現場を見せてもらい、さらにシムスは金星通過観測のための装置を私たちに見せてくれた。

［解題］

・冨田淳久は佐野常民の指示でロンドンのケンジントン博物館（現ナチュナル･ヒストリー博物館）に博物館調査に来ていた。チャールトンとはグリニッジ王立観象台の旧地名、T&Sはトロートン･アンド･シムズTroughton and Simmsという光学器機メーカー。また、このSとはシャボーHenry Schaubauということになる。当時同社の主幹であったJames Simmsから、金星通過観測の一年以上前にその観測装置を見せてもらい、観測手法の指南を受けていた。マクヴェインがこのようなことができたのは、山尾庸三名（工部大輔代理）で同観象台に事前に協力依頼をしていたからであろう。マクヴェイン日記の別頁から、1873年に測量チェーンをはじめとするすべての測量器機はこのT&S社に、また気象観測器機はカセラ社に発注したことが分かる。現在、国立科学博物館に展示されているT&S望遠鏡は、その後に購入したものであろうか。工部省測量司は1874年1月に内務省に移管され、同年8月30日には測量司廃止内務省地理寮量地課発足となった（太政官達）。

・マクヴェインの出張は河野と同じ7ヵ月だったので、1873年暮れには日本に帰国していなければならなかった。しかしながら、T&S社は生産が間に合わず、注文した品物を受け取り、自身で梱包するまでマクヴェインはイギリスに留まることにした。そのことも含め、逐次マクヴェインは山尾に電報で報告した。1874年2月になって測量観測器機を受け取り慎重に荷造りし、その発送をシャボーに託して2月末の船便に飛び乗った。開成学校英語教師のグリスビィとボアンヴィルの婚約者のメアリを日本に同伴することになっており、これ以上遅らせるわけにはいかなかった。

・当初、1873年5月にT&S社に発注し半年以内には納品される予定ではずが、最終的には10ヶ月間掛かったことになる。遅延の理由は注文書発送に手間取ったこと（河野がそれをせずに木戸の待つパリに出発してしまった）、また同年後半に同社に大量の注文が舞い込んでいたことによる。1874年12月に起きる金星日面通過観測のため、世界各国がこの事業のためそぞってT&S社に光学器機を注文しており、同社は生産が間に合わなくなったのであろう。

-2) McVean Diary 1874, November - December.すべてメアリの記録である。

Wednesday 2 Dec Beautiful bright day. In the afternoon I drove Mrs Klasen & Mrs Cheeseman to Ueno where we walked about for a while. Mr Campbell Harry & Colin all went into the Joyners after dinner. 

Thursday 3 Dec Pouring wet day. Colin to office in Jinrikasha. Mr Campbell compelled to remain in doors he busy with curios that the Nikko men brought. 

Friday 4 Dec Lovely morning, cold. Mr C. and Harry Black went with Mr Katata to see duck netting. Colin made a around of calls at the Kogaku-rio we went according to appointment at Mrs Ayrtons but I came home after that. The de Boinvilles & Mr Stewart came up after dinner a little music 

Saturday 5 Dec Fine cold morning. went out about 8 A.M. to admire Fuji Yama. Mr Campbell out curio hunting. In the afternoon Colin & I drove to the Grigsbys & Summers found them all at Home. In the evening we all dined with the Joyners.

Sunday 6 Dec Lovely day. Mr Shaw preached a missionary sermon. Simpsons dined with us. 

Monday 7 Dec. Looked out before 6 A.M. most lovely morning. Crescent moon bright saw the rest in shade all the sky illuminated towards the Sun rising direction. Breakfast about 7 ten Mr. C. Colin & Mr Joyner off to Kurodas to see the duck netting Mrs Joyner & I followed about an hour & a half afterwards & saw them net several ducks. Colin &c busy about the preparations for the Transit of Venus. We all returned to dinner at Mr Kurodas at 7 o'clock very good dinner & very pleasant evening extempore drawing 

Tuesday 8 Dec Lovely day. Eeverybody under the delusion that the Transit was to take place today & Mr. Joyner & Mr. Campbell off to Gotenyama to prepare everything. Baby & I out driving. Gentlemen Home in the evening having been busy preparing Mr. C. & we dined at the Dyers.

Wednesday 9 Dec. Lovely day. Gentlemen off to Gotenyama to survey Venus which they did very successfully. Mr. C. superintending one telescope from which was thrown a shadow of the Sun & Venus on to a sheet of white paper Venus shewed on the paper about the size of a ten [sou] piece. Came Home tired but pleased with their success. The Mikado did not come but Sanjo Daigin did. C & I dined with the de B. Mr. C. with the Simpsons.

Thursday 10 Dec. Lovely day. Colin & Mr. Campbell went down together by the 1 15 train Mr. C. to remain Colin returned by the 6 p.m. train. He & Mr. Scharbau went to call on the Mexican observers of Venus. I called on Mrs. Anderson & Mrs. Rymer Jones. A quiet evening which was pleasant. Rain in the evening.

［和訳］

・12月2日水曜、素晴らしい晴天。私は午後にクラセン婦人とチースマン婦人を伴って上野に行き、しばらく散歩をした。キャンベルと、ハリー（ブラックの息子）とコリンは、夕食後ジョイナー夫妻のところに行った。

・12月3日木曜、小雨。コリンは人力車に乗って事務所に行った。キャンベルは部屋に閉じこもり、日光の人がもってきた骨董品をめぐって忙しくしていた。

・12月4日金曜、気持ちよい朝、寒い。コリン、キャンベル、ハリーはカタタとともに鴨狩りを見に出かけた。コリンは工学寮から呼び出しが掛かり、私たちはエアトン婦人のところに約束通りに行った。しかし、私はその後家に帰ってきてしまった。ボアンヴィル夫妻とスチュワートが夕食後やってきて、音楽を楽しんだ。

・12月5日土曜、晴天、寒い朝。朝8時に外に出て、富士山を仰ぎ見た。キャンベルは骨董品漁りに出て行った。午後、コリンと二人でグリグスビィ夫妻とサマーズ夫妻に会いに行ったところ、みんな家にいた。午後、ジョイナー夫妻を加えた私たちみんなで夕食を共にした。

・12月6日日曜、すばらしい晴天。ショーの説教を聞いた。シンプソン夫妻と一緒に夕食をとった。

・12月7日月曜、朝6時前の外はすばらしい晴天。三日月がまだ太陽が昇る方向に向かってまだ光っていた。7時10分に朝食を取り、キャンベルとコリンとジョイナーは鴨狩り網を見るために黒田のとことに出かけた。私はジョイナー夫人とおそよそ1時間半後に到着し、七羽の鴨が網にかかっているのを見た。コリンとキャンベルは金星日面通過の準備で忙しかった。私たちみんな午後7時に黒田のところに行きすばらしい夕食をごちそうになった。

・12月8日火曜、快晴。私たちみんな、金星日面通過があるものと勘違いしていた。ジョイナーとキャンベルは観測の準備のために御殿山に出かけていった。赤ん坊と私はちょっと散策に出かけた。男性たちは午後家で観測の準備に忙しかった。キャンベルと私たちはダイアー夫妻と夕食をとった。

・12月9日水曜、快晴。男性たちは金星を測量するために御殿山に出かけ、とてもうく成し遂げた。キャンベルは一つの望遠鏡を監督しそれを通して太陽と金星を白色紙の上に十分の一で写してみせた。家に戻ってきて、疲れたけれど、彼らの成功はすばらしかった。ミカドは来なかったけれど、三条太政大臣は北。コリンと私はボアンヴィル、キャンベル、それにシンプソン夫妻と夕食をとった。

・12月10日木曜、気持ちの良い日。コリンとキャンベルは一緒に1時15分の汽車に乗ってでかけ、コリンは午後6時の汽車で帰ってきた。彼とシャボーはメキシコ観測隊に会いに出かけた。私はアンダーソン婦人とライマー･ジョーンズ夫人に会いに行った。静かな夜で気持ちがよかった。夕刻には雨になった。

［注釈］

※1874年11月末、ハーディ事件を決着するための裁判に備えつつ、マクヴェインは金星日面通過観測の準備を進めた。観測手法はシャボーとともに前年にグリニッジ天文台でシムスから指南を受けており、マクヴェインは全体を指揮すればよかった。写真撮影は友人のブラックに協力依頼をした。心強かったのは博識のジョン・フランシス・キャンベルが来日した事で、このキャンベルが望遠鏡操作の指揮をとったことがメアリの日記から分かる。二つの観測所があり、公式のものはシャボー、チースマン、クレソンの三人が、キャンベル個人のものは、マクヴェイン、ジョイナー、ミエの3人が操作した。キャンベルは、日本政府工部省とスコットランド気象協会との間に支援合意書があることを知って来日したと考えられる。キャンベルが指揮した望遠鏡に装着されていたカメラで10枚の写真（10個の金星の陰？）を撮影した。この観測場面には現れなかったが、後日、工部大学校のエアトンは金星日面通過のメカニズムと距離計算手法などをアジア協会定例会で講演した。ここで大事な記述は、「ミカドは来なかったが、三条はやってきた」というところで、ミカドに招待状を出していたということである!!!(revised in August 30, 2019)

※原口孝昭「明治７年の金星日面経過観測 : 観測隊の動向，政府等の対応，派生事項について（1999年）」を神奈川県立図書館で見つけ、2019年7月5日に部分複写をさせてもらいました。(revised in August 30, 2019)

-2) McVean's Correspondenceマクヴェイン書簡資料

［注釈］

-3) McVean's Imagesマクヴェイン画像資料

・Observation of Venus Transit金星日面通過観測

［注釈］

*This is more formal than Far East's photo, as Ito sits on right hand of Sanjo, Murota is still in his right position, next to Murata. Foreign officers are engaging in operation, Klasen, Scharbau, Cheesman, Stewart, Campbell, Joyner, McVean, Witten.

・"The Far East"に掲載された写真と比べると、招待者が落ち着いており、また伊藤博文が三条の右隣に座り、室田がふさわしい位置にいるので、こちらの方が記念写真らしい。撮影者は、通過観測写真を担当したマイケル・モーサー。

IV. Consideration考察

・既往研究の再検討から新資料の分析を通して、以下のことが明らかになった。

4-1. Preparation of Observation金星日面通過観測の発端と準備

・工部省測量師長マクヴェインがどのように金星日面通過観測を行う事を決め、準備を進めたのか述べる。

・マクヴェインがいつ何のための金星日面通過観測を行おうとしたのかは、彼が残した文書には明確に述べられていない。しかし、1872年1月に技術員の雇用と機器の購入のためにイギリスへの私費一時帰国を山尾に申し出て、許可されているので、この時点で測量のために天体観測を行おうとしていたことは間違いない。

・天体観測に関する知識と経験は、海軍水路測量局勤務の経験のあるマクヴェイン、シャボー、チースマンは持っていた。海域の測量では天体観測は自分の位置を知るための必須の知識であった。

・1874年12月8日から9日にかけて金星日面通があることは、その数年前から西洋科学者の間で大きな話題になっており、『ネーチャー』などの科学雑誌に世界各国の準備状況が紹介されていた。そのことはジョン･フランシス･キャンベルの日本旅行記の冒頭に書かれている。キャンベルは法曹界の人物であったが、エジンバラ大学には博物学を学ぶために入学し、法学部から卒業した。政府の要職を務める傍ら、さらに民間の北方灯台局など科学技術関連機関の事務局長を務めながら気象や天体の知識を深めたらしい。1854年には太陽光記録計を発明している。彼の才能は自然科学に留まらず、ゲール民俗文化の研究で大きな足跡を残した。マクヴェインと文通し始めたのは1874年に入ってからのようで、キャンベルの来日前にどのように連絡を取り合っていたのかは不明。

・マクヴェインが金星日面通過のあることを知ったのは科学雑誌からだけではなく、水路測量局にいた海軍士官ウィリアム･フランシス･マックスウェルや契約測量師ヘンリー･シャボーからである可能性もある。両人ともマクヴェインと密に文通していた。

・測量司では、最新器機によって緯度経度を精確に計測し、精度の高い三角測量地図を作成しようとしていたのであろう。購入した器機は、他国派遣の金星日面通過観測隊が用いた望遠鏡と比較すると小口径のもので天体観測専用のものではなかった。

・測量司では単に金星の日面通過を観て写真撮影するだけだったが、他の観測隊は太陽の直径や地球までの距離を計測するためのデータを取ろうとしていた。

4-2. 観測器機の入手

・一時帰国に合わせてイギリスで器機を購入するため、ジョイナーとともに購入予定品のリストアップを行った。ジョイナーは地震観測については門外漢のようだった。

・1873年3月にマクヴェインが一時帰国する前に、山尾庸三に測量司の業務に気象観測と天体観測と地震観測をも含む旨の了解を得て、イギリスでそのための器機の購入と操作修得を行おうとした。山尾が太政官に提出した文書では「測量のための人員の雇用と器機の購入」がマクヴェインの公務旅行の目的で、留守政府を預かる大隈重信に直談判し、山尾は3800ドルを確保した。マクヴェインは山尾からそのお金を受け取り、河野に預けた［マクヴェイン日記］。

・1873年3月の出発前に、マクヴェインは各器機製造メーカーに注文書を送り、関係機関に協力依頼文書を作成した。工部省法律顧問であったデビッドソンの同席で、マクヴェインは日本政府の工部省測量師長として行動できるように山尾から地位保証をしてもらった。河野通久が注文書と照会文書を携え、ロンドン到着後すぐに発送するはずだったが、それを失念して木戸が待つフランスに旅発ってしまった。そのことを7月になってマクヴェインは知り、エジンバラからロンドンに出向き自ら処理した［マクヴェイン日記］。ここで2ヶ月の遅延が生じた。

・グリニッジ天文台に9月になってからシャボーと行くことになったのは、同天文台への協力依頼文書の発送が遅れたためと考えられる。

・T&S社への発注を7月に行い、12月に注文品の受け取りに行ったが、製造が遅延している事の返事を受ける。そのため帰国が遅れる事を山尾に打電した。

・1874年2月早々、ロンドンでT&S 社とカセラ社に注文した品物を受け取り、丸一日かけて慎重に荷造りした。発送をシャボーに託した。購入した器機（膨大な参考図書も含まれていた）のリストはマクヴェイン文書に見当たらない。

・メキシコ観測隊のディアスの記録によれば、「性能と大きさではわれわれ機械と比べて見劣りするが、反対に仕上がりの点は完璧な製品であり、入手して間もない全くの新品であった。その中には、子午儀、経緯儀、天頂儀および性能の良いクロノメーターが二台あった。一台は天体時間測定用、あとの一台は平均時間測定用であった」とある。

・1874年5月23日に品物は横浜に到着し、ジョイナー一緒に出向き、二人で三日間に渡り荷解きした。

4-3. 観測手法の修得

・1873年9月、グリーニッジ天文台にシャボーと出向き、そこでシムスから金星日面通過観測のやり方の指南を受けた。7月に協力依頼書を同天文台にしたと考えられる。このシムスは翌年の世界5五箇所に派遣したイギリス金星日面通過観測隊を総指揮した（下のイギリスによる金星日面通過観測を参照）。

・スコットランド気象協会にも7月に協力依頼し、マクヴェインには11月になって返事が届いたようで、12月半ばにエジンバラの同協会事務局で協力支援合意を締結した。この時、事務局長アレクサンダー・ブキャンと会い、同協会会員となった。名誉事務局長はトーマス・スチブンソン。The Natureの記事とマクヴェイン日記を参照願う。

4-4. 観測前の準備

・観測器機が到着し、大和屋敷（旧工部省官舎）に運んだが、11月28日までどのような状態であったのかは不明である。The Natureを含め、金星日面通過観測について記事が多数掲載されており、マクヴェインらは承知していた。ただ、大久保と杉浦は超多忙の中で、2月に測量司に大蔵省土木寮の一部を合流させ、8月には測量司を地理寮量地課に格下げし、課内は大混乱していたようだ。

・記録上、内務省の金星日面通過観測が動き出すのは11月24日付け「金星試験之義ニ付伺」からであるが、その前にマクヴェインとキャンベルは何度か工部大学校のヘンリー･ダイアーとウィリアム･エアートンと会談をしており、金星日面通過観測について相談していたと思われる。なぜなら、観測の直後にエアートンはアジア協会で金星日面通過の仕組みと意義を講演して、そこではマクヴェインらが写した写真を紹介している.。当時、マクヴェインがよく知る伊藤博文が内務卿を務めており、この伺を直談判することができた。翌日には、この観測の伺が大蔵省と文部省に伝達された事になっている。28日に大久保が復職する。

4-5. 観測所の選地

・11月末、マクヴェインとキャンベルは東京中心部を毎日歩き回っていた。キャンベルに日本文化を見せるため以外に、観測の場所の選地を目的としていたと考えられる。

・品川南部の御殿山は江戸末期に桜の名所として有名であったが、1862年に五カ国公使館の建設場所となった。公使館が完成すると直ぐに長州藩士の焼き討ちに会い、その後は空地になっていた。

・明治元年から横浜品川間に鉄道を通すために御殿山に切り通しが作られてしまった。旧英国公使館跡地が高台になっており、南側に遮るものがないので、キャンベルはここを選んだのだと思われる。ある意味、グリーニッジ王立天文台の立地とよく似ていた。そちらはテームズ川を見下ろす高台、こちらは東京湾を見下ろす高台。

・しかし、鉄道がすぐ西北脇を通るので、その震動が伝わる可能性はあった。線路を北側に越えたところには八ツ山があり、こちらの方は観測所に選ばれなかった。蒸気機関車が南側を通り、海風によって煙が襲来する危険性があった？

広重「御殿山花見」1850年代Sakura Blussom Events at Gotenyama around 1850 by Hiroshige.

［解説］

・下のファー･イースト誌の「八ッ山橋（品川跨線橋）」とほぼ同じ位置から、海側を描き、眼下に品川宿が見える。この山を二つに分断するように鉄道線路を敷設するために切り通しが作られた。

現在は品川女子学院敷地となっている。

Shinagawa Railway Bridge from the Temporary Observatory. The Far East, 1874.

［解説］

・ファー･イースト誌写真の左手上が八ツ山、中央に八ツ山橋、右手に品川宿の町並み。これは御殿山臨時観測所から撮影したもので、左手前から八ツ山橋に向かって線路が伸びる。この鉄路敷設のために御殿山中央に切り通しが造られ、東西に二分された。キャンベルは、汽車が通過すると観測所の地面に震動が走ったと語っている。

御殿山観測所の位置Location of the Observatory shown in 1871 Map.

［解説］

・1871年地図上に比定してみた御殿山臨時観測所の位置。上記写真とぴったり一致する。現在、御殿山の切り通しには東海道線の他に山手線や新幹線を通すために拡幅され、また第一京浜国道を通すために新八ツ山橋が架けられ、大きく変わっている。八ツ山は関東閣&原美術館、御殿山観測所は品川女子学院中学・高等学校敷地になっている。

4-5. 観測日の様子

［解説］

・1874年12月9日の「金星日面通過観測」の様子で、小屋の下で左からクラセン（子午儀）、シャボー（経緯儀）、チースマン（天頂儀）、スチュワート（時計掛かり）、キャンベル、ジョイナー、マクヴェン、ウィッテン。下段左から荒井郁之助、小林一知、三条実美、伊藤博文、杉浦譲、村田文夫、室田秀雄が並ぶ。

(1) 観測小屋Observation Shelter

・メキシコ観測隊のディアスの記録には、「われわれの観測所と同じ建設方法を取り入れて、横浜と東京の間にある品川の近くに、臨時観測所の建設を開始した」とある。間口3間、奥行き2軒程度の小屋で、南側を開放して3台の望遠鏡を設置した。和小屋に板葺きの簡単な建物で、特筆すべき工夫は見られない。こちらは政府要人と内務省幹部を迎え入れるためのもので、内務省公式観測所である。

・ジョン･キャンベルはマクヴェインと協力して膨大な数量の竹を注文して、観測所骨組みを作った。屋根には黒紙を重ねて貼り、キャンベルは「私のテント」と呼んでいたので、南側が開いた大きな円錐形の構造物だったのであろう。内部に3台の望遠鏡を設置した。公式観測所の隣に置かれ、おそらく上の写真のすぐ右側にあったのであろう。キャンベルのこの観測所の目的は、正確な接触時刻であった。キャンベル私設観測所。

・キャンベルはもう一つの構造物を造っており、それは「覗き小屋Deep Show」であった。これはキャンベル私設観測所と同じように竹を用いて円錐形の形をしていた。

(2) 観測者Observors

-Colon Alexander McVean: Supervisor, Surveyor in Chief.総指揮

-Black: Photographer記録係、写真撮影担当

-Moser: Photographer写真撮影担当

Official Observatory（公式観測所）

-Henry Scharbau: Theodolite指揮者、操作者

-Cheesman: Zenith Telescope操作者

-Klasen: Meridain Telescope操作者

-Stewart: Chronometer操作者、時計掛

Private Observatory（私設観測所）

-John F. Campbell: Telescope操作及びSuperintendent?指揮者

-McVean: Telescope操作者

-Joyner: Telescope操作者

-Mee: Telescope操作者、工部省測量司に通訳事務官として雇われたミエと考えられ（写真あり）、内務省地理寮量地課でもマクヴェインらと一緒に行動していた。

Peep Show（覗き小屋）

-Campbell: 記録係、操作者

-Black & Moer: 写真撮影者

(3) 参観者Watchers

公式観測所への招待者

-三条実美Sanjyo Sanetomi

-（大隈重信）Ookuma Shigenobu不明

-（大久保利通）Ookubo Toshimichiほぼ確実

-伊藤博文Ito Hirobumi

-杉浦譲Sugiura Yuzuru

-室田秀雄Murota Hideo

-荒井郁之助Arai Ikunosuke.初代気象台長になる人物で、当時は開拓使技官であった。

-小林一知Kobayshi Kazutomo. 二代目気象台長となり、当時はマクヴェイン配下の地理寮量地局技官。

※荒井と小林は箱館戦争に参加した旧幕臣海軍技師で、その才能を惜しまれ簡単な処罰の後明治政府に出仕した。小林は内務省では村田や室田よりも低い地位であったが、この写真に見られるように周囲を威圧するような雰囲気を持っていた。この二人は明治政府の中で復権を果たすために、薩長土肥の執行部と外国人技術者を排斥する必要があった。Japan Weekly Mail誌「明治政府は献身的な二人の御雇い技術者を失う」の記事の通り、荒井が開拓使御雇いのデイを、小林が内務省地理寮量地課のマクヴェインを排斥した。

-塚本明毅。地理寮職員であるが、顔写真は特定できず。

-水野。顔写真は特定できず。

(4) ジョイナーはどうしていたか

・1874年マクヴェイン日記（メアリ執筆）によれば、12月8日までジョイナーも御殿山観測所設営に加わっていた。フランシスコ・ディアス・コバルビアス『メキシコ天体観測隊日本旅行記』では、ジョイナーはメキシコ観測隊観測所に来る予定になっていたが、実際はこなかったと記されている。これについてはジョン･キャンベルの観測記録ではジョイナーがキャンベル側の観測所に観測者として参加していたことが記されている。キャンベルに感謝(revised in July 23, 2019)。

［解説］

・上写真の三条実美の左手にいる二人は小林一知と荒井郁之助であるが、この大物二人の列席を新聞が紹介しなかったのなぜだろうか。荒井は初代中央気象台長、小林は二代目に就任。

・下写真では伊藤博文が消えている!!!。小林一知と荒井郁之助に挟まれた和服の人物は室田秀雄。、三条と荒井の間には空隙があり、座席が用意されていた。大久保利通以外に考えられない（大久保日記参照）。

・参議の三条実美と伊藤博文が出席したというのに、事業担当の内務卿大久保利通がいないというのは合点がいかない。写真の三条と小林の間の席は隙間が空いており、ここはおそらく大久保内務卿に予約されていた。大久保日記には「十二月九日今朝伊地知子入来林子入来 九字ヨリ皇居に参昇清国随行官員一同然御学問所謁見被 仰付清国談判ニ付一同太儀之段 勅語有之難有御禮奉申上候終る内待所参拝神酒弊物ヲ賜ル控所ニ退く綿三巻紅白縮緬四匹宮内省山岡ヨリ拝領被 仰付随員ニモ夫々賜リ候 十一字此退出税所吉原同車川村氏ニ参金星経過一覧イタシ候」という記述があり、大久保は確かに金星日面通過の観測所に来たのである。問題となるのは、同日同時刻皇居内でも金星日面通過観測所が設けられ、皇室各位と太政官参議が招待されていたらしい。大久保日記を解読すれば「皇居を税所と吉原と一緒に馬車で後にし川村邸に向かい、そして金星通過を一覧した」のであり、皇居内ではなく、御殿山観測所に臨席したことになる。

4-6. 観測器機及び施設

・観測器機・大川通久記録の中の旧内務省地理寮量地局の測量観測器機写真（沼津市明治史料館）

これに関しては中桐正夫氏（国立天文台・天文情報センター・アーカイブ室 ）が、同アーカイブ室新聞 （2012年6月5日 第600号）にトロートン＆シムス社であることを特定し、現在どこに所蔵されているのか捜索中であることを述べている。また、現在国立天文台に所蔵されている子午儀（下写真左端のもの）が、大川記録の子午儀である可能性を示した。1874年金星日面通過観測記念写真に写る器機と比べると、大川記録写真の三台と同じもののように見える。1875年7月に内務省と測量司の建物は全焼しているので、これらの器機が無事だったのか焼け残ったのかは不明。中桐氏は、トロートン＆シムス社の器機は1875年製であるらしいと見ており、そうすると焼失後、全く同じものを再購入したのかもしれない。国立天文台旧職員の中桐氏とのコンタクトを試みたが、すでに退官されて、連絡が取れなかった(revised in AUgust 30, 2019)。

4-7. 観測後

(1) 内務省及び量地課の建物全焼

McVean Diary

Saturday Jul 3, 1875. Rain during the night

[Colin] Naimusho & survey office burned to the ground, All original Plans lost also Field books and many instruments.

Tuesday Jul 20, 1875.

Up about 5 with Baby who had rather a restless night. About 6 o'clock went to look for Fuji saw it beautifully at that time it was already very hot in the sun but nice & cool in the shade.

Thermometer at 7 A.M. 82

[Colin] Letters Mull - T. Cowan with copies of childrens register of Birth - Penicuik [Ja] & George asking him to send to Troughton & Simms abt Balance of Insts ordered by me. - Dresser abt birds & curios.

1875年7月3日、内務省及び量地課の建物に火災が発生し、オリジナル図面、野帳類、多くの機器が焼失した。

1875年7月20日、ジョージ･コーワン（マクヴェインの従兄）に発注した装置の代金不足分をトロートン＆シムス社に送ってくれるようにお願いした。→新しく器機を注文した？

V. 参考文献Reference

(1) 工部大学校教授エアトンによる金星日面通過の仕組みと距離計算方法の解説

Ayrton's Account on the Transit of Venus, ASIATIC SOCIETY OF JAPAN. The Far East 1875 vol.6-7.

From a Special Reporter of the "Tokei Journal" revised by Professor Ayrton.

--ON Tuesday evening Professor Ayrton delivered a lecture on the Transit of Venus to the members of this Society and their friends, who filled the large room of the Grand Hotel and who numbered about 130. The meeting was presided over by Mr. Good-win, who was supported by Sir Harry Parkes, the Russian Minister, Mr. Russell Robertson, Captain Oesterreicher, and other influential members. In introducing the lecture; the President expressed his lively satisfaction at seeing so numerous and intelligent an assemblage pre-sent to hear the approaching phenomenon discussec•and briefly explained. He presumed that all his hearers felt interested in the Transit of Venus, although if they were asked defiffitely, to explain why they felt interested, and why they ought to be so, many might find it extremely difficult to adduce sufficient reasons.

--Yet all of them knew that learned men in all parts of' the world attached great importance to the accurate observation of the event, that the Governments of various countries had appointed stations and fitted out expeditions to watch the events which were about to take place Well, why this expense was gone to, and this trouble taken, Professor Ayrton had kindly undertaken to explain, and he now had only to ask him to fulfil his kind promise. We were glad to see that the beaten path usually followed by the Asiatic Society of reading a written paper was departed from. Not only was Professor Ayrton's lecture not written, and therefore not read, but in addition no notes of any kind were used by that gentleman during the course of the evening. We feel sure that such extempore speaking carries with it a force and earnestness almost impossible to obtain with any read lecture, and in addition is the method best calculated to hold the continued attention of a general audience, such as was assembled last Tuesday evening. The Lecturer commenced by adverting to the importance of the event, to which the world had looked forward for so long a time with the deepest interest an event which, from its rarity and importance, had brought hither Mons. Janssen and his party from France, Prof. Davidson from America, Signor Covarrobias with his colleagues from Mexico —which had temporarily converted Egypt, the Sandwich Islands, New Zealand, Rodriguez, Kerguelen Land or Desolation Island into British observatories for the time be-ing—and had led to many other countries sending American, French, German, Russian, Dutch, and Italian astronomers which had been the cause of donations in the aid of astronomical science from the governments of France, America, Germany, Italy and Britain.

--The British Government giv-ing $75,000, the American $130,000, the Ger-man $90,000, the French $60,000, and the Russian defraying all the expenses at 26 stations. The Government grants for the expeditions amounted on the whole to more than one million dollars, and in addition expeditions had been fitted out by private persons.—by Lord Lindsay and Colonel Campbell in great Britain, and on the continent by several foreign astronomers. "What is there in "this transit of Venus to-morrow which causes " it to he regarded With such exceeding " interest by learned mon throughout the " world ? " The immediate answer to this is :—" It will citable us to ascertain =untidy the Sun's distance from. the Earth." And to astronomers that is everything. It cut the Gordian Knot which had long perplexed them ; though to very many per-sons it might seem an uninteresting problem. But when it was remembered that this distance being ascertained, the tables giving the imam's position at any moment will be much improved, so that the power of accurately calculating longitude will also be very much increased, it will be seen that the acourate determination of the sunrs distance from the earth is a problem of immense importance to nautical men and travellers.

--Without the knowledge of the stn's distance we know not its mass or sise ; a very slight error in the determination of the sun's distance would increase or diminish its volume by many millions 'of cubic miles, and would alter its estimated mass by many multiples of the earth's mass. The relative distances of all the planets from the sun are known ; but noi, the actual distance. We have correct celestial maps, but they are wanting in completeness—we don't know the scale on which they are drawn. The sun's distance from the earth being aocurately known, the scale of our astronomical map will be known. In order to arrive at the ends which astronomers desire to achieve, it will be necessary to determine very accurately the longitude of a very large number of out-of-the-way places. For example, at all British stations the parties of observation will wait three months to correct the longitude of their sites. Thus, each party of observation will be the means of indicating the exact position of its station on the earth's surface more accurately than has hitherto been done by geographers.

--Then, as each has been accompanied by geologists, botanists and na-turalists, the knowledge of the flora and fauna incident to their place of observation, and of its mineral peculiarities will probably be increased. He had heard it remarked :—" If there was only an eclipse to-morrow, " or something one could see ! but a mere spot " in the sun, how very uninteresting ! " But this is not the way it is regarded by men like Janssen, like Struve, like Airy.

--To them it means a world as large as oar oven coming between us and another world mil-lions of times as large as this earth ; to them to-morrow's Transit will furnish the key to the lock every astronomer longs to open. They know that their calculations will lead to almost immediate results, and those too practical ones—the rectification-of the lunar tables, after—who should say what ? Galvani's experiments on frogs which he wee dissecting for purely philosophical purposes, led to the discovery of Galvanic electricity ; and astronomers might feel that when they are dead and gone, but certainly not forgotten, to-morrow's observations will lead to discoveries and results of a kind now little anticipated,—results which now none of our ablest minds could anticipate or even divine, just as Volta's experiments which followed those of Galvani's have led to the discovery of the Electric Telegraph.

--Before considering how the Transit of Venus led to the discovery of the san's distance, he might mention that the ordinary method which a surveyor world employ in _measuring the distance of an inaccessible spot from his site, it was utterly impossible to employ in the measurement of the sun's distance, although in the case of the measurement of the moon's distance it might be utilized with very great accuracy. (The lecturer here illustrated by means of diagram I. the method by which a base line being measured and known, together with the terminal angles, it was possible to ascertain the moon's distance.) By this method., we were enabled to ascertain the distance of the moon within about 20 miles ; but if it was conceived that the method, instead of being applied to an object 31 times the distance of the earth's diameter, was applied to one 11,000 times that, then the lines of observation would become nearly parallel, and the method gave no satisfactory result. So, to determine the distance of the sun, it became necessary to apply an indirect method. We knew the relative distance of all the planets from the sun. If, therefore, we could find the absolute distance of any planet from the sun, or any planet from the earth, we should know the absolute distance of the earth from the tan. In the case of Venus, we should see that the transit enabled us to ascertain Venus' distance from the earth : knowing the relative distance, we should know Venus' distance from the sun, and afterwards, the earth's distance from the sun. Venus, we all knew, passed between the earth and the sun; in other words, the orbit of Venus was smaller than the earth's orbit. When at VI diagram II, she would be merged in the back distance and unillaminated.

--At V' she would appear like a morning star rising' before the sun ; at Vz like' a half moon ; farther on again at V' she would look like a fall moon, at V' gibbous, and at V4 like a half moon again. In the latter two positions she will be an evening star seen shortly after sunset. When Venus is nearest the sun, she is 26,000,000 miles from the earth; when farthest from us, she is about 158,000,000 miles away. Consequently her apparent size differs very much as is shown in the lower part of diagram II. Now we may consider how a, passage of Venus across the sun's disc will enable ne to ascertain Venus' distance from the earth. Venus as seen from a point El (diagram HI) in the northern hemisphere will appear to describe the chord I'm' ; from a point E in the southern hemisphera she will apparently describe the shorter chord 1.m. If we can ascertain the perpendicular distance between these two chords which is the same thing as the angle which this perpendicular subtends at the earth, we shall then know the angle that this line subtends at Venus, since this bears to the former the proportion the earth's distance front the sun bears to Venus' distance from the sun.

--In fact, it is in the ratio of 7 to 2. We then have a triangle, the base of which we know, and a vertical angle. The only point is "How aro we to know this aright 2" There are various methods of ascertaining this. The first is to photograph the sun with Venus upon it a groat number of times dur-ing the transit. Then, by combining all the photographs, you get the lino required, and find your problem solved. Another method consists iii measuring the distance between Venus and the sun's centre at every moment of transit, and taking the shortest distance in each hemisphere, which will give us the result required. The earliest method, how-ever, suggested, is the method due to Halley, which consists in observing the time taken by Venus to cross the. San. We know the rate at which she apparently does so, that is hop:, fast a telescope must be turned in order to follow her motion; therefore, if we know how long it takes for her to cross the sun we know the angle which she describes. We know the apparent diameter of the sun, and therefore we can draw the chord correctly on a picture of the sun. Thus we have the photographic method, the heliometric method, and the method of duration. It might be considered that every time there would be another transit eight years after. But another person whose name 'was Remelts, who lived at Hoole, near "Liver-pool, who was quite a young roan and very poor, who had neither elaborate tables nor Costly instruments, but only tables which gave him inaccurate results, set to work, *corrected their erroneous calculation, and himself deduced from their corrected reason-* that a, transit ought to occur in November 24th, 1639, old style. He communicated this idea to his friend Crabtree, who lived at Manchester.

--Horrocks' method of observing the transit simply consisted in making a hole in the shutter of his window, and Snmg in it a telescope—not an elaborate combination of philosophical and optical devices each as fortunes are spent on now ; but a thing costing half a crown. By this method ha succeeded in viewing a bright image of the Han cast upon the wall of the darkened room. His calculations based on the published tables all gave him November 23rd as the date of the expected transit, while the corrections he applied to these tables gave him November 24th. On the 23rd he watched and saw no transit, but on the 24th he saw the black spot passing across the bright solar imago. He, however, was not able to turn his observation to any great practical account, because he died two years after, at the age of 28. The next transit, which occurred in 1761, was predicted by Halley. Previously to that, the method of Delisle's had also been suggested. Both these methods—that of duration and Delisle's—were employed in watching the 1761 transit. The results were tolerably in accordance. In the next transit, 8 years after, both methods were again employed, but the results were far from being in accordance. At the beginning of the 19th century Encke worked at all the results which had been obtained by the two methods tip to the era of the 18th century. Ho was compelled to reject the results obtained by *certain observers as being quite wrong. By doing so, and taking the amended observations as the basis for fresh oahmlationa, he obtained a result approximating to 95,000,000 of miles as the earth's distance from the sun. This was aeoepted for many years, as correct.

--It might be thought it would have been impossible that any doubt should be east on Encke's result, until the occurrence of a new transit ; but Laplace, the French astronomer suggested a totally different method of deter-mining the son's distance The moon goes round the earth, in addition to both going round the sun, and when the moon is between the earth and the sun, it is attracted by the sun more than when it is on the other side of the earth. It is a very slight difference of attraction, but it differs sufficiently to enable us to determine the sun's distance. The method was worked out in 1854 by the distinguished astronomer Hansen, who deduced a result nearly 4,000,090 miles less than had been determined by Enoke. Leverrier considering the slight irregularity in the earth's motion, due to the earth and moon revolving round the common centre of gravity of the two, was enabled to calculate the sun's distance, and arrived at a result differing by only about 600,000 miles from that obtained by Hansen. Another experiment also led to the same result. We knew that sound took a certain time to reach us. Similarly, al-though for all practical purposes light may be considered to come to us instantly, it is not really so, when we take long distances. It was found that the moons which accompany Jupiter, of which there are four, were eclipsed by Jupiter later than the time calcu-lated, when Jupiter and the earth were on different sides of the sun, and before their expected time when they were on the same side. The Dane Roemur, in 1675, suggested, as an explanation of this, that light takes a certain time to come to us from Jupiter, and that consequently it took leas to come when they were on the same side of the sun than it did when Jupiter and this earth wore on different aides of the sun. It had been observed that 16 minutes 36 seconds was in reality the time taken by light to travel across the earth's orbit. From that Roomur decided that light must move with a velocity of 196,000 miles a second. Afterwards M. Foucault, the French philosopher, experinvented on the velocity of light with a rotating mirror, and Stead of that number obtained 186,000 miles a second, which showed either that the experiments were wrong, or that the diameter of the earth's surface could not be so great as Encke had determined it.

--This, and other experiments, showed the necessity of reducing the earth's orbit from 95,000,000 of _ miles to about 92,000,000. The lecturer now referred to a diagram VIII illustrative of the apparent contact of the planet with the sun, commenting on the apparent largeness of a luminous hemisphere as compared with a dark disc of similar size, due to the irradiation of light. When Venus crossed the sun the contrast of the dark planet on the bright disc caused the sun to appear too large and Venus too small. In diagram VIII the continuous lines in-dicated the appearance the sun and Venus would have at the moment of true internal contact if there were no irradiation, the dotted lines their actual appearance ; Venus having consequently a pear shaped form. Some of the old astronomers had noted the true contact of Venus in their observations of former transits. Mr. Stone very carefully read what they Mated and endeavoured to find the real time of each True contact and Apparent contact. To arrive at these he had to allow as much as seventeen seconds in some of the observations When he had done this, he arrived at almost exactly the same result as had already been o' tained by Laplace and Loverrier, viz : 91 millions and a half. The next diagram (No. IX) showed the appearance of Venus on its entering the sun in the transit of 1769 illustrating very clearly the "Black Drop," which had been a cause of much difficulty in getting the true time of contact.

--To obviate this an artificial transit was pre-pared in England and elsewhere—a bright disc representing the sun and across which a glass plate, on which was attached a small black disc, was made to move by clock-work at a speed corresponding as nearly as possible with that at which Venus actually crossed. Each observer noted all the particulars of each transit a great number of times, and by sending electric signals at the moment any stage was completed to record his observations, the 4.)ereonal equation of each astronomer was obtained. They will thus be prepared all to agree in their observations, and ac-curacy is ensured. In addition to this Struve the Russian astronomer had been travalling from country to country and comparing his observations with those of the various observers—Consequently this indirect method which had been pursued with indefatigable perseverance by Struve would enable the astronomers of different countries to compare their results with one another. He had said that the relative distances of all the planets were known to us. They were so by Kepler's law, but in the case of the planets, such as Venus and Mercury whiCh pass between the earth and sun, it was comparatively easy to determine their relative distances in a very direct way, (the lecturer here explained diagram No. X showing the periods of approach and recession.) The telescope was first pointed on Venus when the sun and earth were in conjunction, and then turned gradually, day by day, fallowing Venus, till it is found that to do so any longer, it is be-come necessary to turn_it back again. This maximum angle S E V was noted, and its incident ray was the tangent of Venus' path. We had then a right-angled triangle in which one of the acute angles was known, therefore the ratio of the sides. For the practise of Halley's method it was necessary to get a northern place of observation where the transit would. begin as early as possible and end as late as possible ; that is, a place where the duration would be a maximum ; and another southern place of observation where transit would begin as late as possible and end as early as possible, that is a place were the duration would be a minimum.

--We required in fact a. place both of accelerated ingress and retarded egress, and another both of retarded ingress and accelerated egress. For Delisle's method two places were required, one where it should begin as early as possible; and one where it should begin as late as possible ; or, on the other hand, one where egress should be as early as possible, and one where it should be much retarded. Now must be considered what places on the earth's surface satisfy these conditions, and which in addition are accessible and likely to be favoured with fine weather. Diagrams No. XI and XII, were here referred to for the purpose of illustrating the points of contact, and egress, together with another No. XIII, giving the appearances of the earth, seen from the sun. From diagram No. XIV, which represented the earth as seen from the sun at the moment Venus' shadow-cone VV. (diagram XII) passed over the centre of the earth at ingress it was seen that the places where ingress was most ac-celerated. were Hawaii and Woahoo.

--The next position was at Tokei, where as seen from the cross lines it would be visible about four minutes later that in Hawaii. Next, it passed to Nagasaki, where it would be observed two Minutes after Yokohama and Tokei. Thence, to Shanghai and Poking, and so on. Those were selected as northern stations. Now, these were required at which to watch the most accelerated ingress, and next others had to be selected at which to watch the most retarded ingress. There were Mac-quarie Island, Rodriguez island, Mauritius, Bimrbon, Kerguelen, MacDonald island, to almost• all of which observers had been sent. To persona there the transit would commence late, some twenty two minutes later than it would appear to persona at Hawaii, these being places of retarded ingress. Again by referring to diagram XV, which represented the illuminated portion of the earth at the moment Venus' shadow cone VV' (diagram XII) passed over the earth's centre at egress, it was shown that the places of accelerated egress were to a great extent coincident with those of retarded ingress and the stations of retarded egress coincident with those of accelerated ingress In addition, however, South Australia might be reckoned among those of accelerated egress and Peshawar and Egypt among those of retarded egress. But Peshawar and Egypt did not see the beginning. of the transit, in the Bathe way that Hawaii and Woahoo did not see the end. Consequently the very best station for observing accelerated ingress, though useless as regarded the end of the transit, was Hawaii aid, therefore admirable for Delisle's method, though useless for Halley's. Bnt at Hawaii the sun would be down, and by reason of refraction of the mass of air through which the light had to pass, Japan world perhaps, however, answer better for even Delisle's method. Similarly Peshavrnr, Alexandria and and Cairo answered well for stations of retarded, egress, but as at these it

would be night during ingress, -these sta-tions, though very valuable for Delisle's method would be useless for Halley's.

--Certain circles on the map indicated the elevation of the sun when the transit passed over each place. With reference to the photographic method of observation, it was the first time photography had been applied for such delicate observations ; but it would be largely employed by the American astronomers, though it was attended with many obvious difficulties, arising from defects in the plates on which photographs were taken, the collodion employti, etc After numerous experiments, it had been found that the dry albumen process had given the best results yet obtained. It had also been adopted by Mr. De La Rue, the English astronomer, because, in Item where the temperature was very high, the wet process was almost impossible, though the shrinkage of the film might be reduced to a minimum by the use of albumen, and the irradiation by the employment of a highly bro-mixed collodion with a strong alkaline development. The French would use the Daguer-reotype process, which also reduced the shrinking of the film. The German astronomers would employ the Heliometric method to s great extent. This chiefly consisted in measuring Venus' distance from the sun at various times, and determining the bearing of Venus with reference to a fiducial line and was effected by a very ingenious invention.

--The object glass of the telescope was divided into two, one half sliding over the other so that by optical displacement-, Venus always appeared to coincide with the sun's cehtre, and the distances ascertained by the aid of "a micrometer screw motion. England would chiefly confine herself to the employment of Delisle's method, and Halley's—the method of duration —secondarily. The Russians in-tended to apply all the methods and compare results with those obtained by other nations Lord Lindsay—who had a most complete expedition of his own,—world use photography chiefly ; but alsoother methods. The times, at which the transit would be visible at Yokohama would be .—First external contact Ilh. Chn. 42 sec. First internal Pt  la. 27m. 42 end „   8h. 22m. 24 At 8ocand external   8h. 49m. 42 lt -To the ordinan observer with a teleacope, it would be very difficult to obtaiti the elect momenta, because, owing to the irradiation, Venus would not appear to be in the sun to the eye, till sometime after it. really was go. It would also be impossible to see it with the naked eye, fox a similar reason. The transit would- take place across the Tipper part cif the. sun, to-morrow. To give some idea of the deitettcy of astronoinical niessurethent, he might state that the times of' contact could now be calculated to the first place of decimals of a minute. This was a very situ.: in fact; but what was wanted now was to . obtain, if possible, the right figure for the second place of decimals, and tills under favourable circumstances, would pro-. bably be obtained.

--Mr. Ayrton 'here de-monstrated the minuteness of the observations of Stone, Laplace and others With regard to Measuring the distance of the sun, tantioning as an illustration that the 're-cent corrections were equivalent to accurately measuring the diameter of a five yen piece at eight miles distance. He drew especial attention to the erroneous idea of relative sizes and distances of the planets that Must be obtain-A from any ordinary diagrams, and showed how correct notions might be arrived at, namely, by considering the slip as a globe twd feet in diameter Venus a small pea about 1443 feet away from the sun, and the earth atibthor small pea about 200 feet from the ann. He then resumed his seat. M. Goodwin tendered the thanks of the assemblage to the lecturer for the remarks just heard, which must have so greatly in-creased the interest of all present in the ap-proaching event, a former repetition of which phenomenon had 240 years ago been witnessed by one obscure Englishman alone of all mankind.

--Let them bestow a thought in de-vout reverence upon the memory of that man. Professor Ayrton showed us the advance the human mind had made up to this moment, how we had attained an accurary of observation almost beyond dispute, how the degree of intellectual science we had attained enabled our learned men to calculate the movements of the heavenly bodies, to observe the fulfil-ment of their anticipations with an accurracy of record almost incredible. But lets es not be too elated. We eqtre hat pigmies 'abrading upon the shoulders of a few intellectual giants, whose aid mai:fled its to intelligent/Ty witness some of the great wonders of the universe. lie would !lay no more, but only ask them to award their thanks to the lecturer for his admirable exposition of the subject he had treated upon; and also to Mr. Smalley, who had prepared the diagrams under the direction of Mr. Ayrton, by which the points, somewhat 'difficult to understand without their aid, haft been so skilfully elucidated. (Applause). Mr. Ayrton acknowledged the compliment, observing that a piece of smoked glass wee all that was necessary, to see something of the transit ; and suggested as a hint to the ladies not to put the smoked side towards their faces, as by that moans they might avoid extraneous black spots. lie added that the transit would be across the upper limb of the sun. There had been some confusion, be-muse some people thought the eclipse would occur on the 8th. The reason of this was, that astronomers reckoned the day to commence—not from twelve at night—but, from twelve at noon, and to end at twelve at noon. So thus, the next morning, the morning of the 9th, vies a portion of the 8th to astronomers. The local time, of the eclipse written in astronomical time would be 8th December 2312 0.7m. The meeting then separated.

(2) Mexico’s international scientific expedition to observe the 1874 transit of Venus

Sep 182010

In an earlier post, Novelist who loved geography set a story in Mexico, which his publisher labeled South America, we referred to Mexico’s first international scientific expedition in 1874.

This is the expedition that social historian William H. Beezley says was linked by many Mexican writers to Jules Verne’s fictional epic, Around the World in 80 Days, published the year before. (Mexican National Identity: memory, innuendo and popular culture).

Beezley’s account has one significant error; he mistakenly writes that the international expedition was to observe an eclipse of the sun, when in fact its purpose was to make measurements during a transit of Venus across the Sun. Venus only transits the sun infrequently, but then usually does so twice in eight years.

Mexico is not commonly associated with astronomy, despite the fact that archaeologists and archaeoastronomers have worked out that several indigenous groups including the Zapotec, Aztec and Maya all constructed astronomical observatories and were able to predict eclipses and other events in the skies with incredible precision. Perhaps even more remarkably, an international astronomical congress appears to have been held in Xochicalco in the 8th century BC.

We can not be certain how much the ancients knew about astronomy, but by the 18th century, British astronomer Edward Halley had worked out that if only the transit of Venus could be observed from several different places, the differences in timing could be used to calculate the precise distance of the Earth from the Sun, a distance known as the astronomical unit. Unfortunately Halley died in 1742, before he had the chance to observe the next transits of Venus in 1761 and 1769. [The most recent transit of Venus across the Sun occurred on 8 June 2004; the next is expected on 6 June 2012.]

Obtaining an accurate figure for the astronomical constant was one of the greatest challenges for astronomers of the time. In 1760, a French astronomer set out for India (for the 1761 transit) but failed to arrive in time! Undeterred, he remained in India, waiting patiently for 1769. Alas, on that occasion it was too cloudy to make any worthwhile observations.

Mexico’s connection to the astronomical constant began at this time. For the 1769 transit, Spain had granted permission to another French astronomer to join a party of Spanish astronomers setting up a temporary observatory near San José del Cabo on the southern tip of the Baja California peninsula. A short distance away, a creole astronomer Joaquín Velázquez de León had traveled from Mexico City to make independent observations. Only days after the transit, three members of the Franco-Spanish party, including the two principal astronomers, died of yellow fever.

By the time of the next transit in 1874, large scientific teams had been assembled by several countries including France, Russia, Germany and the USA to collect better data for a more accurate calculation of the astronomical constant.

Mexico had a fledgling astronomy community, but decided it must send a team to Yokohama, Japan. The team consisted of:

Francisco Díaz Covarrubias (the expedition’s leader) who had written various books and had installed the first post-Independence astronomy observatory in Chapultepec Castle, Mexico City, in 1863.

Francisco Jiménez – whose offical qualification was as a “geographic engineer”. He had fought in defense of Chapultepec Castle when the USA invaded in 1847, written about the 1769 transit, and been a key member of the Mexican Border Commission which fixed the definitive Mexico-USA boundary in 1856. He helped coordinate research for the great map of Mexico produced by Antonio García Cubas. Jiménez was the first person to use telegraph signals to determine longitudes in Mexico with precision.

Francisco Bulnes was the expedition’s chronicler and the youngest member of the team.

Agustín Barroso had wide interests in natural science and engineering, and became an early enthusiast of photogaphy and its applications to astronomy. He was responsible for the outstanding sequence of photos of the transit of Venus taken as part of the Mexican scientific expedition’s work.

Manuel Fernández Leal was an expert surveyor and educator who had also participated on the Mexican Border Commission.

The team traveled to Japan and were able to make valuable measurements. Commendably, they published their first results very much more quickly than did the astronomers from all other countries.

Mexico’s scientific community has continued to play an active part in major international research ever since. See for example, our earlier post about Mexicans involved in the work of the Inter Intergovernmental Panel on Climate Change (IPCC). Scientific globalization was under way…

Source: Odisea 1874 o el primer viaje internacional de científicos mexicanos by Marco Arturo Moreno Corral (Fondo de Cultura Económica, 1986)

(3) Sir George Biddell Airy, Account of Observations of the Transit of Venus December 8, 1874, 1881.

INTRODUCTION.

THE first occasion, I believe, in late years, on which the attention of the British public was pointedly called to the approaching Transits of Venus, was ray communication to the Royal Astronomical Society, dated 1857, April 8, " On the means which will be available for correcting the measure of the Sun's distance in the next 25 years." This paper was not limited to the consideration of Transits of Venus, a part of it being devoted to the Oppo- sitions of Mars. Much attention, however, was given to the selection of stations for observation of the Transits both of 1874 and of 1882. On 1864, May 5, I addressed another communication to the same body, relating only to the Transit of 1882, and to the necessity for a reconnoissance of antarctic countries if an observation with the Sun below the pole should be contemplated. On 1868, October 10, I began a correspondence with the Hydrographer, Captain (now Sir George) Richards, on the general subject. On 1868, December 11,1 read a communication to the Royal Astronomical Society, " On the Preparatory Arrangements which will be necessary for efficient observation of the Transits of Venus in the years 1874 and 1882." This paper was accompanied with eight maps of the regions which appeared proper for the observations of. Ingress and Egress, accelerated and retarded by Parallax, in the two Transits. An active discussion followed, in which the Hydrographer and several Navy Officers took a prominent part. On 1869, February 15, I sent certain papers to the Secretary of the Admiralty ; on April 9 I wrote more formally with Estimate of Expense of Instruments ; and on May 25 I sent a printed copy of the discussion of 1868, December 11, including also a paper by Mr. De La Rue on the application of Photography. About the same time an Estimate was furnished by the Hydrographer for expenses of travelling, residences, &c. [Each of these estimates proved ultimately much too small, the deficiency of my own being mainly in respect of observing-huts and general packages.] Approval to a certain extent was given by the Admiralty, and instrumental and other preparations were begun. Those transactions were reported to the House of Commons on July 6.

The Board of Visitors of the Royal Observatory, at their meeting of 1871, June 3, passed the following resolution : " After a discussion it was " resolved, that, as the Board deem it most important that photographic- " be combined with eye-observations at the approaching Transit of Venus, " an opinion in which the Astronomer Royal fully concurs, the Chairman " apply to the Lords Commissioners of Her Majesty's Treasury to sanction " a grant of five thousand pounds (5,0001.) for the purpose ; a sum which it is " considered will cover the cost of photographic apparatus and observations " for all the stations." The Board of Admiralty requested my opinion on this proposal, and in reply, though expressing myself guardedly on its success, I gave my opinion in favour of it. Meantime the general plan of the proposed Expedition had become the subject of much public discussion ; and in particular, letters appeared in the " Spectator" of 1873, February 8, and the " Times" of February 13, strongly urging the adoption of Bnderby Land (which after careful consideration I had rejected) for a southern station. The Board of Admiralty sent these papers for my opinion, and in my reply, dated February 21, after elaborate discussion of the question, I declined to recommend that adoption. At their Lordships' request, my reply was communicated to the Royal Astronomical Society, and it is printed in their Monthly Notice of 1873, March 14. On 1873, March 22, a statement on the general plan was made to the House of Commons. Preparations had now advanced for collecting an efficient body of observers from all classes, Naval, Military, and Civilian, and for their instruction at the Royal Observatory in all the practical details of observation with the Transit, the Altazimuth, the Equatoreal, and especially with the working model of the Transit. Among the candidates who early offered their services was Captain Gr. L. Tupman, R.M.A. I soon found that this gentleman might be trusted with a large portion of the superintendence of preparations and instructions, which, amid the engrossing business of the Royal Observatory, it was impossible for me to undertake completely. On 1873, March 21, I gave in an elaborate Report of preparations, and stated that valuable assistance had been received from Captain Tupman. The Board of Visitors of the Royal Observatory, at their meeting of 1873, June 7, passed the following resolution : " That in consideration of the fact " that the successful result of the entire scheme of observation of the" approaching Transit of Venus will depend to a great extent on observations " being made in the Southern Hemisphere, to compare with those which are " already amply provided for in Siberia and China, it is in the opinion of " the Board of Visitors very desirable that parties suitably equipped be " despatched to the South, in the hope of finding some additional practicable " places at which the entire duration of the Transit may be observed." The Admiralty, in reply to the Board of Visitors, adverted to the voyage of the " Challenger," and to the prudence of waiting for reports from that ship. I may here state that subsequent information thus obtained justified the entire rejection of the Heard Islands, on account of the extreme uncertainty of communication (the Crozet Islands had been previously rejected for the same reason), and indicated unexpected facilities in the adoption of the southern part of Kerguelen Island. On 1874, January 24, I placed before the Admiralty a general statement of arrangements, and on March 11, Captain Tupman was first put in commu- nication with the Accountant-General, the Director of Transports, and the Hydrographer, for management of the expedition when afloat and of its money-affairs. On May 4, in reply to a letter of the Admiralty, I offered my strong testimony to the value of Captain Tupman's services. The greater portion of the observing parties sailed in the early part of summer ; that for Egypt naturally much later than the others. Time, however, was occupied by the Egyptian party at Greenwich in practice for the operations with the long submarine telegraph. The several parties returned at different times : the breaking up of their residences depending, for the most part, on the completion of operations for longitude. On those points information will be found in the several Parts of the following work. Some advance had been made by each party in the orderly record and partial reduction of their observations. As soon as Captain Tupman returned, all the observers were placed under his superintendence, at the Royal Observatory, for completing their share of the reductions and for measure of the photographs. As the work of each observer was finished, he was discharged from the service. The last was Lieut. Neate, R.N., from Rodriguez ; his return was late, and his calculations voluminous ; and they were not finished before October 1876.

(4) The Royal Observatory Greenwich Telescope: Simms No.1 & Simms No.2 (6-inch equatorials)

The 6-inch refractors known as Simms No.1 and Simms No.2 were two of the six 6-inch refractors on an equatorial mount purchased by the Government for the British Transit of Venus expeditions of 1874. Whilst the four other instruments were all purchased second hand, the two ‘Simms’ telescopes were purchased from new and were made by the firm of Troughton and Simms, from whom five transit instruments, four portable altazimuths and several other instruments were also commissioned for the various expeditions. The Object Glasses had a diameter of 6-inches and a focal length of 78 inches. Prior to being sent abroad, both Simms instruments were set up at Greenwich for testing. The two photographs (right and below right) were taken in 1873 or 1874 in the Reserve Ground in the north-east corner of Greenwich Park.

The 1874 Transit of Venus expedition

The British set up five Stations across the globe from which to observe the 1874 Transit.Designated stations A to E, the locations were:

Station A – Egypt

Station B – Hawaiian (Sandwich) Islands

Station C – Rodriguez Island

Station D – New Zealand

Station E – Kerguelen Island

The two Simms Equatorials were sent to Station C (Rodriguez Island) and Station D (New Zealand). Referred to inititially as the C and D equatorials, Simms No.1 is believed to have been sent to the former and Simms No. 2 to the latter. On their return, the telescopes were put into store at Greenwich.

Transfer of the instruments from the British Government to the Royal Observatory

Together with many of the other Transit of Venus instruments, including the four other 6-inch Equatorials as well as two 4-inch Simms Equatorials (confusingly referred to as Simms detached No.1 and Simms detached No.2), the two 6-inch Simms instruments were formally transferred to the Royal Observatory in 1876. It was at this time that the two six-inch Simms instruments appear to have become formally known as Simms No.1 and Simms No.2, though the earlier designation was still ocassionally used. In 1876, the Station C Simms (Simms No.1?) was sent, together with a number of other of the Transit of Venus instruments, to the South Kensington Museum for their loan exhibition of Scientific Instruments (RGO6/278/670).

Despite the fact that the telescope shown in this photograph and the one below is in a hut marked Station B, it is thought to be one of the two Simms 6-inch equatorials. This attribution is based on the fact that it was so identified by Forbes (who was on the expedition to the Sandwich Islands) in his book The Transit of Venus (published 1874) and also on two other photographs of what are said to be a Transit of Venus Equatorial by Troughton and Simms (one in a hut marked station C?) which are in the collections of the Science Museum in London. Reproduced under the terms of a Creative Commons Attribution-Non-Commercial (CC BY-NC) licence courtesy of Cambridge Digital Library (see below)

The telescope is on a German mounting. In this image, it is on the eastern side of the meridian. In the top image, (which was reproduced as a woodcut, in the 27 June 1874 edition of The Graphic) it has been reversed and is on the western side. A third, wider angle photograph, was also published as a woodcut in Forbes' book. Reproduced under the terms of a Creative Commons Attribution-Non-Commercial (CC BY-NC) licence courtesy of Cambridge Digital Library (see below) The 6-inch refractors known as Simms No.1 and Simms No.2 were two of the six 6-inch refractors on an equatorial mount purchased by the Government for the British Transit of Venus expeditions of 1874. Whilst the four other instruments were all purchased second hand, the two ‘Simms’ telescopes were purchased from new and were made by the firm of Troughton and Simms, from whom five transit instruments, four portable altazimuths and several other instruments were also commissioned for the various expeditions. The Object Glasses had a diameter of 6-inches and a focal length of 78 inches. Prior to being sent abroad, both Simms instruments were set up at Greenwich for testing. The two photographs (right and below right) were taken in 1873 or 1874 in the Reserve Ground in the north-east corner of Greenwich Park.

(5) ジョン･キャンベルの「金星日面通過観測」の記録（一部）Report of the Observation of the Transit of Venus by John F. Campbell

MY CIRCULAR NOTES.Extracts from Journal, Letters Send Home, Geological and Other Notes, Wtitten while Travelling Westwards round the World, From July 6, 1874 to July 5, 1875 by J. F. Campbell, London, MACMILLA.N AND CO. 1876.

The Japan Gazette.

"The Transit of Venus, so long, so anxiously, and so universally looked forward to by the astronomers and scientific men of all civilized nations, made its appearancetrue to its time, and has become a thing of the past. In Yedo and Yokohama the day was happily everything that could be desired, and as our readers have already been told of the observations successfully made at Yokohama and its neighbourhood, by various observers, so we now relate that Japan did not allow the occasion to pass without having her observers at work at Tokei.

" Unfortunately she made no preparations until within the last fortnight. Magnificent instruments of the necessary kind had, however, just been received from home, for survey purposes. They are of the very best kind made for such uses ; and though probably not quite so powerful as would be especially prepared for such important observations as that to which they were applied yesterday, yet they wore sufficiently so to make observations which will be of great value, as the contribution of Japan to the congress of scientists, to whom will be submitted all the observations taken every where, for the grand calculations of the distance between the Earth and the Sun.

" Although so short a time was left in which to make preparations, Mr. McVean, the head of the Survey Department, whilst officially notifying the Government of the great disadvantages they would labour under, as compared with those who had taken time by the forelock and got everything in order long before, yet set to work with great energy. Mr. Scharboo, who has been engaged for upwards of twenty years in the Meteorological Department of the British Admiralty, and who has been specially engaged for similar duties in Japan, also exerted himself, and, assisted by Messrs. Klasen and Cheeseman of the Survey Department, managed to get a temporary observatory erected, good solid granite foundation blocks placed, and the necessary instruments levelled and well adjusted on them. The Japanese officers were equally anxious to forward the operations, and thus evinced the true spirit in which Japan seeks to take her place among the nations. It was too late to have any proper apparatus fixed for photographing the transit, but two days before, Mr. Black having been requested to give his aid in this way, had cameras on the ground, and took the sun at intervals of from two-and-a-half to ten minutes, taking, in all, seventy images.

" The instruments used were a twelve-inch theodolite and a transit instrument; at which were, respectively, Messrs. Cheeseman, Scharboo, and Klasen. Mr. B. Stewart attended at the chronometer. The observations taken by them were confined to the exact moments of contact of the outer and inner edges, both in the passage of the planet on and off the snn's disc ; this date we hope to be able to present in a few days.

" A most admirable picture of the transit, throughout its entire course, was thrown by means of a telescope on a sheet of double elephant paper, stuck on a Japanese door. This was suggested and entirely carried out throughout the day by Mr. Campbell of May, who, as a traveller round the world, happens, to have been staying with Mr. McVean in Tokei for some days. The telescope was on a stand placed on a box about six feet high, and the door with the white paper was in a little dark chamber about six feet square, made of a framework of bamboo covered with black paper. The box standing in front of the chamber, the eye-piece of the tele scope was admitted into the latter through a slit in the covering, and being properly focussed, a beautiful image of the sun, fully three feet in diameter, was thrown upon the white paper, and the planet, when fully on, was like a round black water about an inch in diameter. At the first moment of contact Mr. McVean, Mr. Joyner, Mr. Campbell, and Mr. Mee, the latter a native gentleman connected with the Survey Department, were watching; and they saw the first contact some time before it was shown by the instruments, thus evidencing the advantage of size in such observations. The appearance of the planet as shown by the instruments was only about one-tenth or one-twelfth the diameter as shown on the paper. It was a fortunate thing for all visitors that Mr. Campbell was present, and had the forethought on the previous day to suggest the erection of this little " peep-show," as he humorously called it. To the numerous Japanese visitors who during the day arrived on the ground it gave at once a clear conception of what was going on, without the trouble of applying their eye to any instruments what ever ; although most of those who did present themselves were permitted to see what was to be seen with the more scientific appliances.

"His Majesty the Mikado, who was expected, did not visit the observatory ; but His Highness Sanjo Daijin arrived about noon, and was evidently very much interested in the proceedings. As Mr. Mozer (who had kindly accompanied Mr. Black, to help in the photographic operations) was about to take a picture of the observatory for the December number of the Far East, His Highness very kindly seated himself in front, with a number of other Japanese gentlemen and others connected with the day's doings, and the picture was taken.

" Throughout the day, Mr. Mozer prepared the whole of the plates, while Mr. Black exposed them and took the time, The images are very small ; but, if enlarged, from their con tinuity throughout the entire day, from the commencement to the close, they should be valuable, as showing precisely the course taken by the planet."