LOGA, 1920
Inventor
Daemen SCHMIDT
Invention date
Unknown
Manufacturing date:
1920
Manufacturing location
Switzerland
Manufacturer
LOGA
Dimensions
L 58 H 20 W 22 (143)
L 47 H 10 W 12 (158)
Reference Number
143/158
History and Functionality
The LOGA Company manufactured these instruments between 1900 to 1970 from a patent filed in Zurich by Daemen-Heinrich SCHMIDT (1856-1934).
The machine consists of an inner cylinder which can rotate on its axis on which 60 sections of a logarithmic scale are printed.
Regarding the first machine: the length of the cylinder is 50cm of which 40 are used for the scale leading to a total logarithmic scale length of 24 meters. Around this cylinder is a grid of rules parallel to generatrices of the cylinder. There are a total of 60 rules of 25cm which is the equivalent of a 15 meters long rule. The numbers on the black circles help to quickly identify the number that is sought on both scales.
Six different models are made with scale lengths: 1.2m, 2.4m, 7.5m, 10m, 15m and 24m.
The two models of the exhibition have lengths of 24 meters and 15 meters.
About The Inventor
Heinrich Daemen Schmid founded Loga Calculator AG in 1900 in Zurich, later moving to Uster near Zurich. Under his leadership, Loga became a prominent manufacturer of cylindrical slide rules, renowned for their precision and length, with some models featuring scales up to 24 meters.
Loga Calculator AG was known for producing the world’s largest commercial cylindrical slide rules with a scale length of 24m
The company was a significant player in the analog computing world until it ceased operations in 1978.
