Science Sittings

New Zealand Tablet, 2 June 1910, Page 875

Science Sittings

BY ‘VOLT’

Art of Papermaking. In the matter of making and using paper we are not in line with the Chinese and other Asiatics, who not only make the finest paper in the world, but apply it to all sorts of uses, making window panes, fans, umbrellas, sandals, and even cloaks and other garments of it. The art of making paper from mulberry bast is said to have been invented in China in the second century B.C. Afterward bamboo shoots, straw, grass, and other materials were also used. The manufacture spread to the adjacent countries. The Arabs learned it in Samarkand, and their learned men carefully kept secret the process by which they made paper for their own use. The crusades made Europe acquainted with the art, and the first paper mill in Germany dates from the twelfth century. The Art of Making a Billiard Ball. Few persons who wield a billiard cue are aware of the time, trouble, and expense of making the ivory spheres. The billiard ball in its natural stale is the principal means of defence for an elephant. In time the elephant falls a victim to the venturesome hunter and he parts with his tusks, which are the most valuable of all his possessions to commerce. Most of the tusks find their way to London, which is the greatest sales market for ivory. In the window of one of the large manufactories of billiard balls in that city lies a tusk about two feet long. It was purchased some years ago, and while being sawn in two the saw came in contact with an obstruction. It proved to be a rifle bullet, which had penetrated the elephant’s tusk when quite young, for the whole inside had a decayed appearance.

There are different kinds of ivory, and only the finer kinds are suitable for making billiard balls. The best comes from the small tusks, which are from four to six inches in diameter at the thickest end. They are sawn into blocks, each section being large enough to allow of the turning of a single ball. The factories devoted to the billiard ball industry in England usually receive the ivory in this shape, the sections being marked so that the turners know from what part of the tusk each piece comes, and in this way can calculate as to its grain and quality. It takes a long time to produce a perfect billiard ball, and only skilled labor is employed. The exact centre of the ball is first discovered by means of measurement. The block is then placed in a socket, and one-half of the ball is turned by an instrument made of the finest and sharpest edged steel. The half-turned ball is then hung up in a net for a while; then the second half is turned and the ball hung up as before in a room, the temperature of which is kept from sixty to seventy degrees. The roughly-turned ball is kept in this position about a year. Then comes the polishing, whitening, etc. A good deal of hard rubbing is also necessary, as the ball, before being used, should be as near a certain weight as possible and measure two and three-eighth inches in diameter. It has been found impossible .to get two balls exactly the same weight. Very often they will'be heavier on one side than on the other, and frequently they split right through the centre. This is due to decay. c The price of ivory for making billiard balls has greatly increased within the last few years, and the demand exceeds the supply. '.- Not until after it has been placed on the table is the real life of the billiard ball shown. The pores of the ivory may close, and then, if the ball is kept m a hot room, it is likely to crack, or it may crack by reason of concussion with other balls. This is one of the great difficulties to contend against. To overcome this the balls should be kept in as even a temperature as possible. When a billiard ball is first used it occupies the first rank. A crack may soon be exposed, and then it is returned to the factory. The nick is shaved off and it comes back slightly smaller in size. It may then find its way into some second-rate billiard room. After some more hard usage it is again returned to the factory, and comes forth again much reduced in size, and probably becomes a cue ball in pool. ' After it is found to be practically useless for the purposes for which it was originally made it is bought by dealers in bone and ivory- and the ball is then turned into buttons or burned and used in the making of ivory black.