Dempster

Wow. Just Wow.

John Dempster, with help from his family built this rule in his basement, using a steam press they also built. Here's a great article about Dempster and how he did it. Dempster wrote the manual, and his wife made the case. Only the cursor and the magnifier were outsourced.

Here are two more articles about Dempster and the RotaRule, both also c/o the Oughtred Society:

Article 1

Article 2

The instrument is just beautiful. The quality of construction is fantastic. The accuracy is phenomenal. What a tour de force!

As of this writing, there are only 49 known RotaRules, and only 2 others as complete as this one - with case, magnifier, and manual. I'm thrilled to own it.

(Please be sure to click on these pictures to see them in full detail.)