In my ongoing search for slide rules, I occasionally stumble across related items that catch my eye. I'll be listing some of these oddities on this page. Stay tuned ... who knows what I might find!
I received this ruler as an extra bonus with my Aristo 0968 slide rule. A simple one-sided soft plastic ruler, it features both inch and centimeter scales as well as the decimal equivalents of a large number of common fractions. A clever idea to help speed up calculations for engineers and architects that would need to deal with scale drawings.
This one is for all you surveyors out there ... it appears to be a small pocket-model leveling tool. A level bubble sits on top of the scope, with a mirror that reflects it into part of your field of view as your look through the scope. As you raise your hand up and down, you can see when the crosshairs match, and determine what is level to your visual height. The scope still works fine, and comes in a nicely beat-up all leather case. Interestingly, I've also seen a virtually identical model from K&E ... looks like they duplicated more than just each other's slide rules. Check out my surveyor's K&E 4100 Stadia slide rule as well, if you're interested. All in all, a nice little antique ...
Judging from the model number, I'd say this is a late 60's model ruler made shortly before the name change to Geotec. It is a small double-sided ruler, made of some unknown wood with celluloid scales. It features a 6 inch ruler and what appears to be a "fifth of an inch" ruler going up to 30 major gradations on the front face. Both marked bi-directionally, and are labelled as "10" and "50" respectively. It also has two scales on the back ranging up to 18 to 24, representing thirds and quarters of an inch, I'd guess, appropriately labelled as "30" and "40". I'm guessing a "20" scale would be in half an inch increments? I know K&E often made little rulers like this as well, but this is the first Hughes Owens model I've ever seen. Interestingly, it has "West-Germany" embossed on the front face, along with the name "Chuck" lightly hand engraved on both sides. It also comes with a stitched, form-fitting textured paperboard-type case with the initials C.StJ. in it. Whoever you are Chuck, I have your ruler ...
Update: Apparently, this type of ruler is known as an engineers scale, used typically by civil engineers to measure dimensions off of scaled drawings. Thus, the "50" scale would be used to read from a drawing that was scaled so that 1 inch = 50 feet, and the so on for the other scales. I understand that these are still commonly used today, although generally purchased in cheaper plastic version.
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