Gunpowder

a well known explosive. Historically gunpowder, or something very like it, was known to the Chinese and possibly the Hindus from the remotest times, and was employed by them in the making of fireworks, especially rockets. The credit of its invention has been given Roger Bacon about 1250, or to the German Schwarz, 1330; but the probabilities are that the Moors brought the knowledge to Europe about this time. Powder was used in the battle of Crecy, 1346, but its common use in warfare began two centuries later. In England the manufacture began in Queen Elizabeth's time. Common gunpowder is a mixture of the following ingredients, which are ground fine and incorporated thoroughly:

American powder mills use 175,000 bushels of charcoal and 1,300 tons of sulphur a year. A spark from a gun cap or a hot iron causes gunpowder to explode or pass instantaneously into gases which occupy 280 times the space required by the powder itself. The gas exerts a pressure in a gun barrel of 100 atmospheres upward according to the charge, etc. The manufacture of gunpowder is a dangerous business. Powder mills are located usually in a lonely locality, and workmen take every precaution; yet accidents are not infrequent, and powder mills blow up with loss of life and property. After the grinding into a fine dust, several operations follow, including the pressing into cakes and crushing into grains, which are polished and sifted into powder of different sizes. A smokeless powder has of late been invented, and is in favor with sportsmen and military authorities.