WORLD-WIDE NOTES.

Pelorus Guardian and Miners' Advocate., Volume 29, Issue 38, 18 May 1917, Page 2

WORLD-WIDE NOTES.

RANGE-FINDING IN AIR DUELS

M. Georges Prades, the French writer on aircraft, indicates the dif- • Acuity of finding the range in an air j duel. If you have two machines flying in opposite directions, each at a speed of ICO miles an hour, and ; tlius having a combined speed of 200 miles an hour, the distance between the two machines varies at the rate of nearly 300 ft. a second, which means he says, that within the space of live seconds required for aiming after estimating the range the target is 1,500 ft. closer than it was at first. If the trajectory of your missile is slightly too curved, you will fire over the target. LUXURIOUS AEROPLANES. The German military aeroplanes are equipped with a minuteness of detail almost equal to an expensive automobile. In the dashboard before the aviator’s seat are little drawers containing a flask of stimulant, a thermos bottle, chocolate cubes, a revolver, a sponge for wiping goggles, and a set of sharpened coloured pencils for marking down the enemy's position, a map case, and a set of maps. The aviator’s seat is carefully upholstered, and the exhaust pipes from the motor are brought up beneath the floor boards, so that his feet may be kept warm at high altitudes. NEVER BEEN BESIEGED. Petrograd is one of the few European capitals which have never been besieged or captured by enemy forces. On May 27th, 1703, Peter the Great founded the city by building himself a small wooden hut upon the .site. In 1710 Count Golovkin built the first brick house, and in the following year the Emperor, ■with his own hands, laid the foundation of a house of the same material for his own residence, and transferred the seat of Government from Moscow to the new capital. ‘ CLEVER PLANTS. The cleverness of some plants is indisputable. A sundew, or fly-eater, deceived by a piece of chalk, seized it in its tendrils, but upon discovering the fraud immediately withdrew them. A fly, held just out of its reach, did not tempt it to move, but as soon as it was brought a little nearer the plant prepared to take possession of it. Darwin showed that a begonia bad a habit of searching for a hole to insert its tendrils into, and even of withdrawing the tendril to insert it in another hole, if the first proved unsuitable. Nor is this power of selecting confined to any particular class. Climbers like the lianas will refuse to coil round a branch not strong enough to bear their weight. * THE ENGINE WHISTLE. It was on Saturday, May 4th, 1833 that there occurred an accident whicli gave us the engine whistle. It was on the level crossing between Bagworth and Thornton that Driver Weatherburn drove the engine Samson into a market cart containing 501 b. of butter and eighty dozen eggs. So serious an affair was reserved for Stephenson’s consideration. A meeting of directors was called, and the manager’s suggestion of a whistle which steam could blow was adopted. He went at once to a musical instrument maker in Leicester, who constructed a “steam trumpet,’’ which ten days later was tried in the presence of the board of directors. In appearance it was like a hunts-' man’s horn, 18in. long and Gin. across at the top. GROUND LIGHTS IN WARFARE. Whenever there is a night attack the battlefield is made almost as light as day by means of searchlights, special -star shells which burst in the sky and throw out a brilliant light, and ground lights. These ground lights are used to illuminate the actual ground over which the enemy may advance, and many thousands have been used by our soldiers, especially when two lines' of trenches are very close to one another. The lights consist of ■ a skeleton circular frame of iron covered over with canvas and filled • with a com- j position of resin, tar, and other combustibles. As a rule they are fired from trench mortars, towards the German wire entanglements, a short fuse lighting the composition. This burns with a dazzling flame for a quarter of an hour or more, and as long as it is burning the surroundings are lighted up sufficiently to prevent' any German attack being made without instantly being seen. j A FEAT WITH PISH. j The feat of freezing live fish and; reviving them several weeks or • months later has been achieved by a, Swiss scientist, M. Pictet. The scion- i tist put twenty-eight live fish in a box that contained water rich in oxy-1 gen, in which several pieces of ice floated. The temperature of the water was then reduced slowly until it*, froze. At the end of about two months the cake was gradually thawed, and the fish, it is said, were found alive. !

In such an experiment, the scientist reports, it is essential that the water he gradually frozen, and that .it shall have contained pieces of ice for from fifteen to eighteen hours before the whole mass is frozen. The process of thawing must also be slow.

Through this process it is believed that Siberian sturgeon and Alaskan salmon can be exported alive to distant markets.