Relatively scarce, quite early, made by Joseph Long and using the early address of Little Tower St London, 1830 - 1860 at this address, late Georgian early Victorian. Unusual as its a long slide rule measuring 12 1/2 inches long for the main unit, a little longer with the slides included about 13 inches , and it has a double slide system. The use is basically all to do with alocohol / spirit / proof etc calculations for casks , bushels etc. No bad warping, the slides moving freely.
All as per the images. The item "ANTIQUE C1840 GEORGIAN double SLIDE RULE BOXWOOD 12 1/2 LONG TOWER ST LONDON" is in sale since Sunday, October 18, 2020. This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "sentinel-collectables" and is located in feering.This item can be shipped to North, South, or Latin America, all countries in Europe, all countries in continental Asia, Australia.