4.5 Years 1930-1939

Number of slide rules: 35.

The vector slide rules became readily available, and a modified Rietz system for the needs of engineers – the System Darmstadt – was established in Germany in 1934. The Darmstadt arrangement placed log-log scales on the back of the slide, and typically includes a P scale on the front. An expansion of Specialty Slide Rules began to take place.

Some notable technical developments: radio, discovery of neutron, nuclear fission, cyclotron patented; radar.

Year Maker Model
c.1930 Hemmi 40
1930 K&E 4093-3
c.1930 MARC promo
c.1930 MARC promo
c.1930 Nestler 24
1930-1935 K&E 4058W
c.1931 Gilson Atlas
1931-1934 Hemmi 153
1933 K&E 4092-3
1933 K&E 4093-3
1933 K&E Mystery
1933 K&E Mystery
1934 K&E 4095-3
1934 K&E Mystery
1935 Faber-Castell 387
c.1935 Hemmi 50/1
c.1935 Hemmi 80/3
1935 K&E N4096
c.1935 Novotni Weight Calculator
1935-1938 Lawrence 8-B
1935-1938 Lawrence 10-C
1936 K&E N4092-5
1936-1940 Hemmi 153
1936-1943 K&E 4058W
1936-43 Hemmi 32
1937 K&E N4053-5
1937 K&E 4081-3
1937-1945 Nestler 23R
1938 Festus Acu-Rule 10D
1938 Festus 50
c.1938 Hemmi 153
1938 K&E N4100
1939 K&E N4053-3
1939 K&E 4080-3
1939-1947 UIF Shanghai 4083-3