My guess by the looks of the size and shape, is that they're somehow related to 19th century dentistry- which was about one step removed from torture! Any suggestions from anyone?
They're available on Ebay.
Here is another set also found online, not quite the same but definitely related.
My guess is it's a wood turning gage. You adjust and lock the screw to hold the desired outside diameter of the turning, then squeeze it on the workpiece as the wood is turned until the caliper leg meets the screw tip. The reason for the scissor design is so it can be easily used one-handed, probably in a production environment while the worker's other hand is controlling a turning chisel or tool feedscrew.
ReplyDeleteNot the safest design because if it got caught in the spinning workpiece say goodbye to your fingers, but it sure sped up production.
The "third leg" design may have been to get around patents for another one that had the adjusting screw between the scissor-grips:
https://thumbs.worthpoint.com/zoom/images1/1/0508/30/vintage-cast-brass-o-d-caliper-gage-wood-turning_1_0eef91bc9168341fbd3190197e9b3403.jpg
Or, maybe it was just more comfortable using the tool with the screw out of the way of the scissor-grips.
Could it be used to determine wall thickness in a bowl or pot either wooden or clay as it is being produced?
ReplyDeleteblacksmiths also use a similar caliper to determine thickness as they work a piece. I doubt with the scissors type handle it would be used on a turning workpiece. You would lose your fingers pronto! But I do really think it was used to reach inside a vase or pot to determine a consistent thickness.
ReplyDeleteThe latest info from the vintage woodworkers site is that these are woodworker pattern makers calipers. Now we can all get some sleep:)
ReplyDelete