Found this....

[AlphaLobo]

I was wondering if anyone could tell me what this is. It seems like some kind of clamp but I'm not sure how it would be used. I can't find any manufacturing number on it and the only identifying marks on it are, No. 1 and 1 1/2, that are stamped into it. From what I can tell it's made out of cast iron and has a wooden handle on it. Thank you for your help.

[OilyRascal]

How long is the wooden handle?  From the picture it looks like the handle to a cross cut saw to me.

[Branson]

We need a better picture.  It's very hard to make out this clamp.

[AlphaLobo]

Sorry, I hope this picture helps. The wooden part of the handle is about 4.5 inches long.

[gibsontool]

Still may not be enough pics to tell but it looks to me like it is two pieces that clamp individually onto a piece of 2x4 or whatever and the piece on the left is the base of the clamp and the right hand piece is the top portion you would position the two pieces onto an appropriate length piece of 2x4 and tighten them separately with the side clamps them tighten the screw on the top piece to clamp whatever your working on tight together.  Most likely a woodworking clamp,That my guess,Jim

[AlphaLobo]

We were thinking that maybe it's used to spread something apart? The piece with the crank on it has to be at the end of the board though otherwise it won't turn. It only fits on a 2" board, so it could only be used on a 2x4 or 2x6 or anything simmilar. The farthest the crank will go out is about 3.5" before the crank runs into the base. We're not sure where or when it's from but we are pretty sure it belonged to my great-grandfather. We only just found it in my grandfather's possesions.

[jimwrench]

 Looks like a furniture clamp to me. Clamp handled piece to 2x4;adjust non-handled end to position to span work piece;use handled end to apply pressure.

[AlphaLobo]

Here is another view that might help too.

[scottg]

Its definitely a cabinet/furniture clamp.  Lots of loose clamp fixture sets were sold and probably still are.
 The fact that it clamps on, instead of the standard pins, its really unusual.
  yours Scott

[wvtools]

I edited my whole post because I was wrong (if anyone read it in the last 30 seconds).  I thought it was a flooring clamp, although the one piece could be used as one.  It is listed on page 47 of the 1924 E.C. Stearns catalog as a Universal Clamp.

[m_fumich]

Old version of a pipe clamp.

[Bill Houghton]

I've got one of those too.  I figure it's either a furniture/bar clamp or a clamp/vise for use in the field/on the jobsite (that is, a carpenter's clamp).  Great heavy creature, with some nice ridging on the clamps that fasten to the 2xwhatever and would mark the heck out of it but hold well.