Just found this text below from an Auction house listing some years ago:
One of of the two is photographed and featured as number 145 on pages 298-299 of "Historic Pistols" by Samuel E. Smith and Edwin W. Bitter. The book states that these three-shot pistols were made between 1815 and 1820 by Peter Peloux of Philadelphia. It is believed that they are the only two in existence that use the Chambers system for multiple fire in flintlocks. Speculation is that the pistols were loaded with three powder charges and three balls with holes drilled through them to ignite the next charge. The action, which is quite a distance from the breech, ignited the closest charge which then ignited the charge behind it, much like a Roman Candle. On March 23rd, 1813, Joseph G. Chambers of Pennsylvania was granted a US Patent for a system of "repeating gunnery." In February 1814, the US Navy contracted with George Tryon and John Joseph Henry for 20 repeating swivels and 200 repeating muskets. Peter Peloux was a gunsmith who had been working under M.T. Wickham at the US Arsenal on the Schuylkill in Philadelphia between 1812 and 1815. After the War of 1812, Peloux had his own shop at 190 Cedar Street in Philadelphia and was listed in city directories between 1816 and 1829. Several conventional flintlock rifles by Peloux are known. He later became the superintendent at the Krider Gun Factory. Peloux would have had a knowledge of the Chambers system and the ability to make the multi-shot system. The pair was possible made for trial, experimental purposes, or as a sample. The barrels are round, one is marked with British ordnance proofs at the breech, the other is unmarked. Both have their original iron ramrods. The intricate locks are stamped "PELOUX/PHILA"