This bad idea seems to be an 8-cylinder, 48-shot percussion revolver with what looks like a pepperbox-style of hammer. Exactly how the multiple cylinders would be indexed into place in sequence is unclear.
The basic shape of the original weapon reminds me somewhat of the lines of the Savage-North .36 Navy Revolver, but the dropping hammer is characteristic of the older pepperbox revolver era.
As Mark Twain testified in his account of his own adventures in the American West, Roughing It (1872), even ordinary 5 or 5-shot pepperbox revolvers had atrociously long and stiff trigger-pulls inevitably resulting in great inaccuracy, and they were highly liable to multiple ignition.
He wore in his belt an old original “Allen” revolver, such as irreverent people called a “pepper-box.” Simply drawing the trigger back, cocked and fired the pistol. As the trigger came back, the hammer would begin to rise and the barrel to turn over, and presently down would drop the hammer, and away would speed the ball. To aim along the turning barrel and hit the thing aimed at was a feat which was probably never done with an “Allen” in the world. But George’s was a reliable weapon, nevertheless, because, as one of the stage-drivers afterward said, “If she didn’t get what she went after, she would fetch something else.” And so she did. She went after a deuce of spades nailed against a tree, once, and fetched a mule standing about thirty yards to the left of it. Bemis did not want the mule; but the owner came out with a double-barreled shotgun and persuaded him to buy it, anyhow. It was a cheerful weapon–the “Allen.” Sometimes all its six barrels would go off at once, and then there was no safe place in all the region round about, but behind it.
Take the inaccuracy and ignition hazards of Mark Twain’s Allen pepperbox, throw in lots of weight and really terrible balance, then multiply the opportunity for multiple ignition by eight, and you have this contraption.
Hat tip to Theo.