Slide rule with case, Richardson's Pantocrat Six-In-One, metal / leatherette, made by the Richardson Slide Rule Company, Chicago, Illinois, United States of America, 1912-1920
Richardson's Pantocrat Six In One Slide Rule, 28cm metal stock with 5 interchangeable slides. The stock and each slide has a folded tin backing with a white painted tin rule inserted into it. The scales are printed onto the white painted surface. The slides are then inserted into the stock as required for the calculation to be performed. In dark leather (snakeskin-look) case with gilt lettering.
US Patent 1911/1/31 & 1912/3/26
Missing cursor and possibly one slide.
Stock, upper: Sin, A,
1776: B, CI, C
1812: B, +-, C
1860: D2, CI, %
1860 LL: C, LL1, LL2, LL3 (folded at e) - Richardson's Logometric Slide
1865 O: C, CI, R - Engineer's Binary Polymetric Slide
Stock, lower: D, Tan, Log (equal parts)
Mfr: Richardson Slide Rule Co, Chicago, Illinois.
Richardson's Pantocrat Metal Slide Rule
on leather case: Richardson's Six In One Slide Rule