This is a very small vise, just 6 in. long and having jaws that are 1 3/4 in. wide and a maximum opening of 1 3/4 in. It was patented on Feb. 6, 1871(no. 187,131) by James F. Hall and Elbert P. Cook of Havana NY. The patent was for the spring loaded plunger on the side that could engage different holes in the swivel base to lock the vise securely in position. The patent date is stamped on the top of the plunger.
When I bought this I had noticed the pin that stuck up in front of the anvil pad but didn't pay too much attention to it since it seemed to be frozen in place. When I got it out to clean it I decided the pin needed to come out. After a little persuasion with a brass hammer it loosened enough so I could withdraw it with my fingers. It turns out that the rear jaw is now free to swivel so that an irregular workpiece may be held more securely.
In addition, the anvil pad is threaded on the bottom so that it may be removed. I assume so that in the event of damage, a new one could be ordered from the factory.
One of the things that had caught my eye was the nickel plating on all parts of the vise. My guess would be that these would have been marketed to jewelers. I'm sure it added substantially to the price.
Apparently the swiveling rear jaw was also available on the larger vises, although I have never seen another Prentiss vise. I'm curious when they went out of business.
Mike
