Hemmi-Frederick Post Versalog 1460-1461
The POST Versalog 1460 models were manufactured in Japan by the Company HEMMI Bamboo Slide Rule Company Ltd., and commercialized in the United States by Frederick Post Company from 1951 to 1969, with a selling price in the late 1960's of $22.95 (about $174.00 USD in 2020) Frederick Post Co, began to commercialize the Sun Hemmi rules in 1931. There was a break during the WWII years with Japan.
This rule was fabricated from a large-diameter variety of bamboo grown in Kagoshima Prefecture on the island of Kyushu, coated on all sides (except the ends) with white celluloid, and held together with metal posts. The glass indicator has a metal frame screwed to plastic ends. The Versalog was a version of the HEMMI 258, and was manufactured in two sizes: 1460 (rule 12 in long, scales 10 in long), and 1461 (rule 7 in long, scales 5 in long), produced since 1957.
With its double scales for square roots and trigonometric functions, was very popular among scientists and engineers. The Versalog has the scales: LL/1, LL/2, LL/3 [ T/T, Sec T/ST, Cos/S, C ] D, LL3, LL2, LL1 on the front face, and LL0, LL/0, K, DF [ CF, CIF, CI, C ] D, R1, R2, L on the back face, This rule did not have changes during the 18 years it was produced. It was replaced in 1969 by the Versalog II.
The Versalog models were produced even after The Frederick Post Co. was acquired by Teledyne Inc. in 1967. After the acquisition, the Versalog models were branded Teledyne Post. The POST Versalog is a high quality and beautiful rule, it is considered by experts a classic, and a must have for collectors. Next pictures include a comparison with the Versalog II model
Next is a Post Versalog 1460 simulator:
A skilled user is able to solve the next problems with a precision of two-three decimals:
SlideRulePractice-2.pdfNext is a scan of the User Manual:
M34_Post_Versalog_1951.pdfNext is a Post Versalog brochure scan (sorry I had to make it in parts)
PostVerslogPoster.pdfClick on the next links to see professional panoramic pictures of the 1460 and 1461 models.
References.
Roos, Paul - Hume, Ted: Slide Rules of the Frederick Post Company. Journal of the Oughtred Society, Vol.9 No.2 Fall 2000. http://www.oughtred.org/jos/articles/V09.2_p37-46.pdf
Roos, Paul - Hume, Ted: Post Slide Rule Archive. Sphere Research Corporation: https://www.sphere.bc.ca/test/post.html An extensive classification of Frederick Post slide rules can be found in this web-page.
Roos, Paul - POST Slide Rule Cross Reference: Every slide rule sold by the Frederick Post Company of Chicago starting in 1903. http://srtco.us/PostCrossRef/Index.htm