- The Chicago Astronomer -
Copyright 2004-2014 All rights reserved by Joseph Guzman Administrator/Founder/Chief Astronomer.
All text and images are the property of the original authors/artists and shall
not be used without permission.
Early Chicago Astronomer Invents a New Calculating machine Circa 1898
The article is describing a circular slide rule. The slide rule was invented in the 1620’s and the first circular one in 1630. When I was in high school and college we used slide rules constantly. Classrooms had huge ones above the blackboard for demonstrations by the teacher. Hand held calculators were not yet available. I even had a slide rule tie clip. We used circular ones when I worked briefly for the FAA in the early seventies estimating the times for aircraft to reach various points. The circular variety was generally less accurate than the linear due to slight jostling in the axis of the wheel.
I have to wonder if that “Chicago Astronomer” actually was issued a defendable patent or simply knew how to promote himself to the public through the press. That latter skill has been finely honed by many politicians in my native Chicago, including a not to be named mayor who forced himself to wear a Cub cap yesterday.
Portrait of William Oughtred (1575-1660) English inventor of the circular slide rule