Last year I was searching for a massive bell that was used long ago as a mooring block. At that time I posted what certainly looks like a bell but it was not nearly big enough to hold down the boat that was tied to it.
With help from the person who told me the story and a relation of the owner of it I found it this year.
While covered in rusted accretion that indicates it's ferrous metal, I am surprised by it, expecting it would-and might be-made of bronze or similar metal.
Probably 5 feet across in size. I would estimate its weight at perhaps 1/2 ton., maybe less.
http://youtu.be/aEdvvM6dz_Y