SCIENCE AND INVENTIONS.

Nelson Evening Mail, Volume XLVII, Issue XLVII, 11 April 1912, Page 2

SCIENCE AND INVENTIONS.

GIANT LOCOMOTIVE. One of tile largest locomotives in the world has just been built for the Pennsylvania Railway. From the point of the pilot t.o the pulling-fh.ee of the \ coupler on the rear of the tender the J length is 98ft 33m. The weight of the engine in working order and with tender loaded is 668,5001b5. COST OF LIGHTHOUSES. An account published in Parliamentary papers shows that during the last complete fiscal year the light dues collected in the United Kingdom were £460,819, the total expenditure on the lighthouse service £465,677, of which Trinity House spent £248,288. A further sum of £14,900 was expended on the upkeep of lighthouses abroad. CORK VARNISH FOR SHIPS. In • order to protect the interior of steel ships from the humidity caused by condensation upon the metallic walls during sudden changes of temperature, the Italian Government is experimenting with a ■"cork varnish." Ground cork is consolidated by pressure with copal and litharge, and the resulting mixture with suitable liquids is applied to the walls like an ordinary coat of - varnish. The tests are said to show that the coik varnish absorbs the watery vapour of the atmosphere to the extent of loz. for each 30 square feet of surface exposed. A MOTOR STREET-SWEEPER.

One more additional use has been found for the automobile —this time in the street-cleaning departments in Paris. The new motor vehicle is a combination sprinkler and sweeper, which gets ovei the roadway at a good, steady pace, leaving a trail of well-swept and wateied highways behind it. The automobile sweeper has been found to do as much work in a given time as ten horse-drawn sweepers or a hundred liand-sweepeis could do. When the automobile streetsweeper was first tested the dust quickly clogged the gearing and motor and put the" machine out of business. This has been remedied by enclosing all the motor parts in a dustproof casing. LEECHES AND THEIR YOUNG. It is known that leeches of the Clepsine family show an interesting particularity in the fact that the females carry the eggs oil their uutler-surface, and. j when the young are hatched they like- i wise fix themselves to the surface by means of their suckers. Ihey lemain there for some time, until they reach about one-third of the length of an •adult specimen, then they drop off and become independent. Recently MMoltschanov, a Russian scientist, observed the fact upon no less than five species of Clepsine from Central Russia. The number of young is variable, being usually from seven to twelve, but in the case of the Hemiclepsis marginata there are often as many as 35 siiian leeches fixed upon the female. If one of them is taken off it crawls until it meets with an adult leech, upon which it becomes fixed. This, says the Scientific American," may even be a specimen of a different, family. Sometimes the female is seen carrying the young, but tliere are one or two of these which are larger than the rest, and these no doubt came from outside and fixed themselves upon the female. CURIOSITIES OF PLANT LIFE.

• Those who are persevering in their efforts to follow Nature in her slow, ! steadv, and wise methods have many secrets revealed to them which are hidden from others. By them Nature is put before us like an open book, full of interesting lessons in purpose, wisdom, and harmony. Fruit, for instance, to most people,, is nothing, more than a piece of palatable matter,- while in reality it is an active living body, having the power of breathing and of using its ; cells in the doing of it just as we do. It is thought to cease living after it has been picked, and to lose size and weight, because of the drying-up of the water in it; yet to those who have taken the trouble to find it out it is known that these phenomena are due to the lack of food to compensate for the loss of cells caused by the breathing after the picking. Hence it has been found that fruits are preserved best in cold cellars, because the breathing is s;x times as. slow in a cold as in a warm atmosphere. It is interesting, also, to know that what we sometimes mistake for dew is nothing less than the perspiration of the plant. This perspiration is considerable at times, as in the weeping willow of one of the Canary Islands, which is able to form a pool at its base with it. In the edible, arum the excretion is thrown out every minute in jets of ten to one hundred drops to a distance of an inch and a-half . The pitcher plant, with its curious long leaves arranged in cylindrical cups, helps the traveller by preserving this clear liquid. It keeps the drink fresh and clean for him by closing the hinged lids at night and opening them in daytime, which allows the sun to evaporate the fluid, a fresh supply of which is then furnished by the plant. Some plants in South America, which have a similar arrangement, go as far as purifying the water from the marshes around them. These processes of breathing and exhaling my be observed •by placing the plants in question in airtight jars. OIL-DRIVEN BATTLESHIPS. The Uvo battleships Texas and New York, which have recently been laid down for the United States Navy, will be unique vessels of their size and power, in that they will -be driven by means of o : l, and no coal, will be carried. Unlike most of the new men-of-war of other fleets, these ships will not be fitted with turbines, but will have reciprocating engines of a new type, which, it is calculated, are about 30 per cent, more economical at cruising speeds than turbines, and cost about the same to run at high speefl. The engineering department of the United States Navy expresses itself highly pleased with the results that have been obtained during a long series of trials. The machinery designed for these two battleships marks, it is claimed, a distinct advance over any other machinery in America or in .any other country. As compared with Tiie United States battleship Delawere, of equal power, the machinex-y weights in the boiler compartments have been reduced by 300 tons, or about 30 per cent. The length of the space required for boilers has been reduced by orie-half, and the fire-room space is one-half that required for the Delawaro. The tactical qualities of the vessels have been improved by diverging the shafts from aft forward, this being made possible through a radical change in the arrangement of engineroom auxiliaries. Each main engine will be fitted with two condensers, instead of.one, as heretofore, and provision is made fov running on one condenser. By reducing the weights in the boiler-rooms it has been possible to greatly increase the armour protection of these battleships, and the boilers will be grouped under one funnel, thus clearing the upper deck and improving the arc or train of the turrets. It is thus evident that the new vessels, with only one funnel, will be remarkable additions to the American fleet. Moreover, each ship will mount ten 14in. guns—throwing a all el 1 of 14001b—and twenty sin quick(irers. Tli.j former will be pl»eed in five elliptical turrets on the centre line, so as to enable them all to be trained on either broadside, while ahead or astern four guns will bear. These vessels, owing to the economy of weight In the enginerooma, will be well protected by armour, behind which the sin. guns will he carried.