the rate of fire were developed, the earliest involving multi-barrelled weapons which allowed two or more shots without reloading. Later weapons featured multiple barrels revolving along a single axis. A matchlock revolver with a single barrel and four chambers held at the Tower of London is believed to have been invented some time in the 15th century. A revolving three-barrelled matchlock pistol in Venice is dated from at least 1548. During the late 16th century in China, Zhao Shi-zhen invented the Xun Lei Chong, a five-barreled musket revolver spear. Around the same time, the earliest examples of what today is called a revolver were made in Germany. These weapons featured a single barrel with a revolving cylinder holding the powder and ball. They would soon be made by many European gun-makers, in numerous designs and configurations. However, these weapons were complicated, difficult to use and prohibitively expensive to make, and as such they were not widely distributed. In the early 19th century, multiple-barrel handguns called "pepper-boxes" were popular. Originally they were muzzleloaders, but in 1837, the Belgian gunsmith Mariette invented a hammerless pepperbox with a ring trigger and turn-off barrels that could be unscrewed. In 1836, American Samuel Colt patented a popular revolver which led to the widespread use of the revolver. According to Colt, he came up with the idea for the revolver while at sea, inspired by the capstan, which had a ratchet and pawl mechanism on it, a version of which was used in his guns to rotate the cylinder by cocking the hammer. This provided a reliable and repeatable way to index each round and did away with the need to manually rotate the cylinder. Revolvers proliferated largely due to Colt's ability as a salesman, but his influence spread in other ways as well. The build quality of his company's guns became famous, and its armories in America and England trained several seminal generations of toolmakers and other machinists, who had great influence in other manufacturing efforts of the next half century. Early revolvers were caplocks and muzzleloaders: the user poured black powder into each chamber, rammed down a bullet on top of it, then placed a percussion cap on the nipple at the rear of each chamber, where the hammer would fall on it. This was similar to loading a traditional single-shot muzzle-loading pistol, except that the powder and shot could be loaded directly into