4.2 Years 1900-1909
Number of slide rules: 13.
The early K&E Mannheim slide rules began to compete with their European counterparts. Inverse, folded, and cubic scales began to become available on the European slide rules. Manufacturers appear to have experimented with a variety of standard scale arrangements this decade in search of more efficient computational power. See, for example, the Dietzgen rules with their special “B” scales (1762-B), as well as the inverse scales and “triplex” scale arrangements on the Kolesch slide rules. The “log-log” scales, invented nearly a century earlier, are re-introduced by K&E on their duplex models at the end of this decade.
Some notable technical developments: Zeplin first flight; Wright Brothers and Kitty Hawk flights; Einstein’s development of special and general relativity; Ford’s Model T automobile.
|1909||Stanley||Fuller’s Calculator Model No. 1|