Circles of proportion
This famous calculator was invented by William Oughtred. This replica is based on the version by Robert Davenport , found at the National Museum of Scotland. See here
Welcome to my slide rule pages.
I have been collecting slide rules for about 20 years, on and off. This site contains images for some of my slide rules, as well as PDF files for PostScript scales that I've made.
In fact, I originally created this site to get my Postscript files off my hard drive. I've had a few PCs die on me, and needed a way to get my SR scale work out of harm's way. Recovery from a backup can be surpassingly tedious.
My overall interest is in the history of computation in the pre-digital era. I chiefly collect slide rules and abaci, as mechanical calculators tend to be too large for me to have many around the house.
Replica scales for a Sexton's Omnimetre, modelled from the National Museum of American History version.
Navigation is via the menu at the LEFT side of the page. Alternately:
Replica Slide rule scales, Items from my collection, Slide Charts and Specialized Calculators, Advertising (Gift) Slide Rules, Unusual Slide rules, Slide rule as a status item
New: The J Michaelson slide rule, US patent 556,761.
New: The GM Andrews spiral slide rule, US patent 486070.