7.11 Specialty Slide Rules

While the majority of slide rules consisted of logarithmic scales for performing general calculations, many were designed for specific computations for very specific tasks. Just as a modern computer program might be used to perform a repeated calculation rather than typing in a series of similar computations again and again on an electronic calculator, special slide rules were developed for repeated calculations such as those found in the fields of electricity and electronics, chemistry, surveying, and so forth. Below is a list of slide rules that may be considered specialty rules in that they have scales specifically designed for use in a particular application or for a particular profession.

Maker Model Year Type Size Note
noID Comparative Rule
1880 L 9.00 nice boxwood Comparative Rule for alcohol taxation, likely from a Sikes’ hydrometer set; one side does comparative values; other side does reducing calc
K&E 4133 1913-1922 L 8.00 Roy Lance Electrical Slide Rule, mahogany, early release; prod mark 255; used and in poor condition; missing original 3-hairline cursor
K&E 4100 1915-1922 L 10.00 Stadia rule, early model, for use in surveying; instructions on back; all-glass cursor; prod marks 268 on end
noID Engraving Rule
1928 L 5.50 Engraving Proportion Scale; sold by Art Brown & Bro. Inc. NewYork; similar item on MIT Museum page
Hemmi 80/3
1935 L 10.00 Electro; tables on back and text on box in French
Novotni Weight Calculator
1935 L 4.00 Novotni, but not marked as such; 13 inch o/a length; By-Products Steel Corporation; Commercial Trust Building, Philadelphia, Pa.
Lawrence 10-C 1935-1938 L 5.00 Lawrence Engravers / Photographers Proportion Calculator; Wabash, IN
Baetzmann Spring Calculator 1941 L 2.00 Spring Load Calculations slide rule; large format 17 x 2.5 x 0.75 in^3; two slides on front, one on back; owner (maker?) R. K. Baetzmann, 1941
K&E 4139 1946 L 10.00 Cooke Radio Slide Rule; Case: Polyphase Duplex DeciTrig 4071-3S
Lawrence 10-D
1946 L 3.75 Lawrence Lumber Calculator; Peru, IN
Lawrence 10-N
1946 L 6.50 Lawrence Printer’s Proportion Rule; Peru, IN
American Blueprint Military 1948-1957 L 10.00 US Military slide rule, for field artillery problems
Blundell Rules Limited Radiac No. 1 1952-1956 C 2.00 radiation exposure calculator; log log scales; reversible land/sea discs; instructions on back
Pickett N1040-ES 1954 L 10.00 Fisher Control Valve Sizing Rule; made for Fisher Governor Co, Marshalltown, Iowa
Hemmi 257 1956 L 10.00 Chemical Engineering; owner Frank Banks of CA
Concise 380
1959-1966 C 2.00 Radio Computer, with instruction sheet; Concise Co., Ltd. 
Pickett N1010-ES Trig Demonstration
1960 L 40.00 Demonstration rule; originally used in Michigan high school; 1/2 in x 9 1/2 in x 48 in
noID Engraving Rule
1960 L 12.00 18 inch proportions rule, used in printing, engraving; maker? American Blueprint?; A/B scales range from 1 to 30, 12 inches from 1 to 10
Pickett N-515-T 1962-65 L 10.00 Electronics model; leather case, strap – great condition; Cleveland Institute of Electronics
Pickett N-515-T 1962-65 L 10.00 Electronic; basically new-in-box; leather case, strap – great condition; Cleveland Institute of Electronics