Double Caliper ??

[randyjaco]

I picked this up today at a yard sale. It looks like it might have been made by Starret or Lufkin, but has no markings on it other than the number 24 stamped on it. Any Idea of what it is and what it must have been used for. Obviously it must have been used to measure something large and something else smaller.



<a href="http://s640.photobucket.com/albums/uu124/randyjaco/?action=view&amp;current=DoubleCaliper_zps5b0a32e9.jpg" target="_blank"><img src="http://i640.photobucket.com/albums/uu124/randyjaco/DoubleCaliper_zps5b0a32e9.jpg" border="0" alt="Photobucket"></a>

TIA
Randy

[Mel Larsen]

Randy, here is a link to a page about double calipers.  http://www.habairon.org/May09/
Also do a google search for Double Caliper and then click on the "images" link that shows up on the left side of the page, it will show a bunch of double calipers.  One artical I read said they where used in turning wood bowls.
Mel

[anglesmith]

Long handle double calipers are for forging under a large power hammer. Most of the DCs I've seen have been self made by a blacksmith probably while doing his training.  There was a thread on these before? but maybe it was Lost.
Graeme

[randyjaco]

Thanks guys. This one looks like it was factory made, but it could have been put together from parts from factory calipers.

Randy

[Billman49]

Also used by wood turners for repetition work - saves having two pairs...

Some early c 17th century, and some 19th/20th century from a wheelwrights shop

[anglesmith]

Interesting I've always looked at them with blacksmith's eyes, the long handle to get away from the heat of a large rectangular bar. Did the wheelwright use them in making the hubs (turning) or in shaping other wheel parts (spokes and felloes) with draw knives and spoke shaves?  My thought is that the handle seems too long to be used effectively on a lathe, especially a treadle lathe. I'll have to go back to books a bit more I think!
Graeme