Скачать или смотреть Genaille Lucas rules (redubbed Sept. 2025)

Henri Genaille worked as a civil engineer for a railway. Edouard Lucas: a French mathematician. This video starts by describing how the rulers were used to calculate the results of simple multiplications. There are many resources online and texts that do an excellent job of doing this such as the book by Michael R. Williams "A History of Computing Technology". I'd always pondered why the rulers were laid out the way they were how they were designed. After fiddling around with the rulers for a bit the answer was surprisingly simple which made it astonishing that no one bothered to provide any explanations. The last part of the video briefly explains the design.