WHAT BIG GUNS EAT.

Pukekohe & Waiuku Times, Volume 4, Issue 47, 18 June 1915, Page 7

WHAT BIG GUNS EAT.

GUNPOWDER IS ALMOST PI'KE COTTON.

lhe lady who asked at the country stone for "powder" was met with the polite query, "Face, gun. or flea?" The first and third varieties are still what they were of yore, but gunpowder is really powder no longer, except when it

. used for the manufacture of fireworks. That used for the modern high, power artillery is in tiie form of cylinders, sticks, or blocks, some of tliem of considerable size.

A single grain of the powder, for instance, for the great ltjin. gun to be set up at Panama is as big round a.s a broomstick and three inches long. (~>> mans make their powder in strips that look like thick tape. They cut it oil in lengths and tie in up in bundles tthicli lit into the breeches of their big guns. The British powder is made in long sticks which look like macaroni without the large single hole, while the French powder looks like flat pieces of chewinggum.

The bigger the gun the bigger the grain of powder. For the rifles the men carry, the grains are half a: big as a pin-head; for the largest guns they are tlir.ee inches long and three-quarters of an inch thick. Every grain is perforated lengthwise. Sma'l grains have a single hole, while the larger sizes have seven. 'ihese holes regulate in a wonderful way the rapidity with which the powder will burn, if you light a scrap of paper all round the edge it will burn towards the centre and the burning surface will steadily decrease. if, however, you make a hole in the centre of the paper and start the conflagration there the flame will steadily grow, and the most rapid burning will take place just before the fire has reached the outer edge. Thi* is the exact principle which governs the arrangement of the perforations in biggun powder. The burning starts along the surface exposed by the perforations, and spreads always faster a.s the hole is enlarged, burning fastest at the instant it is consumed.

Jt is not intended that the charge in big guns shall exhaust its force instantly, says Mr. William Atherton Pupo>, writing on "Powder for the World's Guns." The beginning of the explosion starts the projectile on its way. The explosion continues, and as the projectile gains speed the force behind it continues to push. The powder is burning fastest and pushing hardest at the iustant the projectile reaches the mouth of the gun. At that instant also it burns out and exhausts itself. Its work is done.

It is wonderful to reflect that gunpowder is almost pure cotton. It requires but little juggling—scientific juggling, to be sure —to convert the harmless crop of the cotton-field into the most effective of modern smokeless powders. Those big grains of cannon powder which look like pieces of stick candy are but cotton refined to this form and treated with nitrate. All nations make their powder of the same materials, the ony difference being in the mechanical form the product takes.