It's heavy, but what is it?

[Branson]

It appears to be a standard tool for Russian coopers, part of the kit rather than someone's experiment.  They're fully developed (I wish I could post the drawings, but I'm unable at this point to copy from the electronic version of the document).  They're built like a hoop driver -- socketed metal business end, and a wooden handle inserted into the head.  So not an occasional or idiosyncratic tool.  I believe that the point of their use is to render a hoop that is a segmented arch rather than a full arch -- thinner while having the same width.   

I'm currently repairing a cask whose wood hoops were made in this way.

[Billman49]

For a quick way to show anything on screen, use PRTSC and then paste into Paint - you can then crop to size... You can also use magnify screen to make things easier.... Here's part of this screen at 300%...