Replica Instruments
A note on materials: I am an inveterate "recycler" and the materials used for the instruments I construct often reflect what I have on hand at the moment. Thus, although brass is the most common traditional metal for instruments, and has the best working/use qualities, a number of instruments are fabricated from copper because I was given a large sheet of 14 G copper. I have also used bronze (from cast plaques) because it was available, though in this case I also find it exceptionally attractive and easy to work. If you are purchasing metal brass is generally your best choice. If you are on a budget, I strongly recommend periodic trips to your local salvage yard, building up a stock of metal as you find it.
Most of my projects involve graduated arcs and/or circles. I have provided a page on graduation techniques with illustrated examples to help others with these processes.
Astrolabes
Astrolabes are probably the the sini qua non of ancient instruments. They have been collected for centuries, and forgeries have been made for centuries, though genuine, working, astrolabes were made in Islamic countries up through the nineteenth century. For background information on astrolabes a number of books are available. Some which I have used extensively are listed among the references for this site. *
For many years I had multiple links to The Astrolabe site. Unfortunately, James Morrison, the creator of that site and its associated items passed away and they are no longer available. His book, "The Astrolabe" is the best source for making astrolabes and associated objects. I sincerely miss him. In his memory I reproduce the note and links here: "The Astrolabe site on the Internet provides a brief essay on the astrolabe, museums having astrolabe collections, a history of the astrolabe, and finally, astrolabe links, references, and reproductions (including my own), including a "personal astrolabe" available for a fee made by that site's creator. "
Planispheric Astrolabe
This is the classic universal instrument of the Middle Ages. A complex project requiring many hours and high skill to do well.
Transitional Mariner's Astrolabe
Based on an example claimed to be Christopher Columbus' own instrument. Probably derived from large wood measuring instruments used by astronomers, which were derived in turn by simplifying the planispheric astrolabe to its measurement basics. An intermediate level project, much simpler than the planispheric astrolabe, but still challenging.
Mariner's Astrolabes
The "wheel" form and weighted "classic" form of the navigator's astrolabe as used by the Portuguese and the Spanish in the 16th and 18th centuries. Somewhat more difficult than the transitional instrument above if fabricated, as here for the wheel form. A realistic model should be made of very heavy stock, and would be better as a casting, as for the traditional model.
Armillary Sphere
This was a teaching/demonstration instrument representing a Ptolomaic model of the universe. Such models were characteristic of the late Middle ages and up into the 17th century. This is a difficult and time consuming project, involving fabrication with a number of different media: metal, wood, and stone.
Torquetum
Also known as a turquet, this is a complex and sophisticated instrument characteristic of Medieval astronomy and the Ptolemaic tradition. This recreation is based on contemporary diagrams, descriptions in the literature, and the requirements for a functional instrument. It is not intended to replicate any specific instrument, but rather to be made in the spirit of the period - it could have been made by a scholar/cratsman of the 13th or 14th century. This is a difficult and time consuming project, involving fabrication and shaping of metal and wood, along with extensive scale division.
"Canterbury" Sun Dial
"Canterbury" dial: modeled after a dial found in the walls of Canterbury Cathedral during repair work in the 1930's. Thought to be 9h or 10th century. This is a relatively simple metal project which I have done as a fabrication from bronze plate, and in a simple workshop project in aluminum. It would also be excellent as a casting.
Quadrants
I have created a number of Quadrants over the years. Currently I have them grouped into three categories:
Simple Quadrants
This is a measuring instrument used from the early middle ages through the Renaissance. This is one of the least demanding of the projects listed, requiring some woodworking (or you could substitute cardboard), paper, and ink. I have also used the quadrant as a workshop project using plywood. A nickel-copper quadrant is also discussed.
See description/construction page for these instruments.
Horary Quadrants
A few years ago I became aware of an article describing a marvelous medieval quadrant found in an archeological dig in Canterbury, England. It inspired me to try and create modern replicas of a number of instruments.
See description/construction pages for these instruments.
Nunes Navigation Quadrant
Kamal
Used by Arab sailors since time immemorial, this very simple instrument shares the same principle as the cross-staff, but here the cross piece is replaced by a card, and the staff by a piece of cord. This is a beginning level project, requiring little skill or time.
Cross Staff
One of the most popular navigation instruments of the Renaissance and Age of Exploration, the cross-staff was derived from a larger astronomical instrument invented in the 14th century. The cross-staff largely substituted for the mariners astrolabe in Northern Europe. This can be a simple or an intermediate level woodworking project. In addition to the original project illustrated, a workshop version based on half-inch dowel is also described.
Dry-Card Box Compass
This project was modeled after a 13th-15th century Italian compass. This is a relatively straight-forward project for those with a wood lathe and some lathe experience. The box was turned from a solid block of maple, the card is made of "parchment" with an ebony bearing sitting on a needle. A magnetized oval of steel wire is glued under the parchment.
Water Clock
Automatic Water clocks such as this were described by the Greeks by 300 B.C.E. They were also known to Europe in the Middle Ages. This is a fairly complex project. Depending on the materials chosen it will take intermediate to advanced skill levels to complete. A labeled diagram is provided here to help in understanding this instrument.
