Jim Gurney has posted my photos of the antique drawing tool I foud at an estate sale a few months ago. Some folks on his blog requested a measured drawing, so I have scanned the parts and put measurements on them for those of you who want to make their own!
Some people have asked about the hardware and the wood type used-
The wood appears to be cherry, a good fine grained hardwood, that is obviously tremendously stable, as it has not warped in 111 years!
The hardware is all brass. small wood screws to attach the head to the main ruler and screws with square heads and a washer and wingnut on the top side.
Hope that helps.
Another bit of helpful information was sent to me by a visitor, so I thought I would share it with the rest of you- There is a book online about mathematical drawing tools and it has a pretty good instruction guide on how to use the tool! Go to page 169, here is the link: