Found this letter yesterday while looking for something else in the Library of Congress. Rather than explain its importance to all you cannon-cockers, I'll let you explore it yourselves. There are many facts in it that I've never heard before, most amazingly that the Navy took Army M1841 6-pounders with them aboard boats (!!!!) through the surf, into Mexico during the Mexican War. You wouldn't get me on any boat with a 6-pounder! The letter is basically Lt. Fairfax's objections to Dahlgren's proposed boat howitzers. Fairfax, among other objections, doesn't want to get rid of either trunnions or the tulip-shaped muzzle on cannons more familiar to him.
Notes on the brief slideshow: There are 4 pages or so that are unavoidably duplicated in the main screen since the minumum slideshow is 9 frames. I may fix that in future by puttiing blank photos in them. Mouse over a thumbnail, then click on it to enlarge, then click again for larger so you can read it.
http://s17.photobucket.com/albums/b62/cannonmn/miscforumsetc/forums25/?action=view¤t=ad8de818.pbw