Dating faber castell slide rules
Dating faber castell slide rules - whoppi goldberg dating
1944 - The word 'POST' surrounded by an ellipse becomes the permanent logo.
COPYRIGHT XXXX and © XXXX 1943 - 2 digit Postal Zone codes to increase efficiency of delivery because of a wartime shortage of staff. 1963 - The use of 5 digit Postal Zip Codes in USA addresses adopted but not mandantory. 1898 After a fire, Bruning rebuilds the New York Blueprint Paper Co., only to close it and return to Chicago. It is not uncommon to find rules in the 1960s in 68 xxxx series packaging but 4000 series model numbers on the rules.We are sure that this was in the early 1960s while they were working through old 4000 series stock.Post sold a wide variety of slide rules, both under its own name and under the names of various manufacturers.1931 to 1941 Slide rules manufactured by Hemmi Seisakusho.1932-1941 - Hemmi-manufactured rules have no date code and are marked "Made in Japan" 1942-1946 - WWII.1963 - The change from state abbreviations to two letter codes (Colo. to IL) 1967 - The use of 5 digit Postal Zip Codes in USA addresses now mandantory. 1896 Charles Bruning leaves Post & Jacobi, and after a honeymoon in Europe, returns to the US and settles in NYC. He sells his blueprint business interests to George W. 1899 In April, Charles Bruning returns to NY and starts the Charles Bruning Co. The Fuller and Thacher's slide rules had their own serial number systems. There were logical groupings of numbers and dash numbers were used to depict length variations of a given rule type.
1983 - The use of Zip 4 Postal Zip Codes began used by USPS Many of the founders of United States firms producing slide rules had their roots as employees in other firms, just as modern entrepenuers break off from their employers and create their own start-up companies. Gustavson, in her article Necessity is the Mother of All Invention (Modern Reprographics, June 2000) is a good example. "N" was used as a prefix many times to denote some change in a given model.
1903 to c1917 Slide rules manufactured by Dennert and Pape c1920 to 1924 Slide rules manufactured by Nestler; Koch, Huxhold & Hannemann; and possibly Faber-Castell.
1924 to 1930 Slide rules manufactured by Koch, Huxhold & Hannemann.
Having contact with the original owner of a slide rule that remembers the year it was purchased helps on determining the age. In general it is safe to assume a linear production rate between the rollover dates particularly for the common types rules.
Other Slide Rule dates are currently in development. Please refer to the museum library and individual galleries as this page is being built. Serial numbers can be used to approximate the manufacture date of a given rule however not necessarily the sales date.
1950 - Two character date codes appear (see Hemmi date codes).