Solving the puzzle.

Heartless Lib was first and mostly correct, and Grumpy was also correct, and Terrapod was assertively incorrect.

But no one got the complete answer (which, to be fair, wasn't going to be likely, anyway, since I was cheating, as per usual).

They are, indeed, powder charges.  Inert, of course.  From left to right - a typical bagged charge of black powder for a Revolutionary War era 3inch cannon (but representative for any black-powder gun of that era).  The second (of which only the base charge was in yesterday's picture) is the M203 powder charge for the 155mm howitzer.  And the last is the base charge increment for the 16"/50 guns of the Iowa-class battleships. 

Read the complete post at http://www.thedonovan.com/archives/2010/10/solving_the_puz.html