The origin of the name "snaphaunce" is somewhat unknown. One speculated origin is from the Dutch phrase "snap Haens", which means "hen thief". It seems poachers used this type of lock for their captured. Others say it's derived from the German word "Schnapphahn" or "snapping hammer".
The flintlock prospered especially in military firearms. The mechanism was relatively simple, strong, reliable, and inexpensive. It eliminated the danger of carrying burning slowmatch. The majority of early colonial American firearms were modeled after European weapons, particularly the flintlock shoulder and handguns. Muskets were copied of the Charleville (Ardennes), a famed French rifle.
About fifty years later, a man named Patrick Ferguson took a serious interest in LaChaumette's invention. He made many substantial improvements on the design, and it resulted in the creation of the most advanced military rifle of the 18th century. One of the improvements Ferguson made was modifying the design of the breechblock. He designed it so that it formed a flat breech face at the rear of the barrel of the rifle when the breech was closed. This minimized the build of fouling on the mechanism which could cause misfires and other dangerous accidents. Another modification by Ferguson was the design of the screw threads and providing recesses at certain areas of the breech plug. Fouling would accumulate in these recesses instead of on the screw threads, which would lead to the mechanism to malfunction.
British military authorites doubted the effectiveness of Ferguson's design. On April 27, 1776, Ferguson demonstrated the effectiveness of his rifle. At a range of 200 yards in hard wind and rain (all of which are conditions that made the current military standard-issue rifles extremely inaccurate if not unusable), he continously fired at targets while both standing and moving all at a steady rate of four shots per minute, a rate of fire unheard of at the time. Impressed by the demonstration, the British military ordered 100 rifles to be produced under the supervision on Ferguson. The following year, Ferguson was given command over 100 riflemen in the special Light Company regiment to test the rifles in actual combat in the American Revolution. On September 11, 1777, the first real test of the Ferguson rifle turned out to be its last. Ferguson was shot in the right arm and wounded, rendering him incapable of leading the regiment which dispersed after the battle and all survivors returned to their former regiments. The rifles in use were taken away and seemingly disappeared, with only a rare few surviving to modern day even though other similar rifles were manufactured by the East India Company for private buyers.
Ferguson remained in the British military after recovering, becoming an Inspector General in Georgia and the Carolinas. Ironically, Ferguson met his end in 1780 at the Battle of King's Mountain, where he was killed by American sharpshooters armed with flintlock rifles, the rifle his invention was designed to replace.
The percussion-ignition system was an important invention in the history of firearms. Before then, the most advance firing mechanism in firearms was the flintlock. The main problem for the flintlock and its predecessors was that they had a slow discharge. Reverend Alexander Forsyth of Belhelvie, an expert in chemistry, mechanics, and sharpshooting, began work to develop a firing mechanism capable of instantaneous discharge. In 1800, a scientist named Edward Howard of the Royal Society discovered fulmate of mercury, a substance capable of a violent explosion if struck. Using his findings, Forsyth began experimentation with explosive powders. In 1807, he patented an ignition mechanism, which relied on a detonating powder consisting mainly of potassium chlorate.
Another important feature of the percussion-ignition system was its ease of modifying current flintlock rifles. This was very important for the military, since upgrading from flintlock rifles to percussion-ignition systems was as simple as removing the flintlock and replacing it with a percussion lock.
"A machine gun firing at 1000 rounds a minute generates about 200 horsepower. The Maxim gun would begin to boil the water in the jacket after about two minutes sustained firing." (The Complete Illustrated Encyclopedia of the World's Firearms)
A man named John M. Browning used Maxim's firing mechanism to create the famous Colt-Browning .30 caliber machine gun. Introduced in 1895, the water-cooled machine gun became a standard, lasting for many years in the military services.
Here is a picture of a tripod-mounted machine gun.