charge, rather than using a piece of flint to strike a steel frizzen. They succeeded the flintlock mechanism in firearm technology. The rudimentary percussion system was developed by Reverend Alexander John Forsyth as a solution to the problem that birds would startle when smoke puffed from the powder pan of his flintlock shotgun, giving them sufficient warning to escape the shot. His invention of a fulminate-primed firing mechanism deprived the birds of their early warning system, both by avoiding the initial puff of smoke from the flintlock powder pan, as well as shortening the interval between the trigger pull and the shot leaving the muzzle. Forsyth patented his ignition system in 1807. However, it was not until after Forsyth's patents expired that the conventional percussion cap system was developed. The caplock offered many improvements over the flintlock. The caplock was easier to load, more resistant to weather, and was much more reliable than the flintlock. Many older flintlock weapons were later converted into caplocks so that they could take advantage of this increased reliability. The caplock mechanism consists of a hammer, similar to the hammer used in a flintlock, and a nipple (sometimes referred to as a "cone"), which holds a small percussion cap. The nipple contains a tube that goes into the barrel. The percussion cap contains a chemical compound called mercury fulminate or fulminate of mercury, the chemical formula of which is Hg(ONC). It is made from mercury, nitric acid and alcohol. When the trigger releases the hammer, it strikes the cap, causing the mercuric fulminate to explode. The flames from this explosion travel down the tube in the nipple and enter the barrel, where they ignite the main powder charge. Revolvers Percussion era In 1836, Samuel Colt patented the Colt Paterson, the first practical mass-produced revolver. It uses a revolving cylinder with multiple chambers aligned with a single, stationary barrel. Initially, this 5-shot revolver was produced in .28 caliber, with a .36 caliber model following a year later. As originally designed and produced, no loading lever was included with the revolver; a user had to partially disassemble the revolver to re-load it. Starting in 1839, a reloading lever and a capping window were incorporated into the design, allowing reloading without requiring partial disassembly of the revolver. This loading lever and capping window design change was also been incorporated into most Colt Paterson revolvers that had been produced