Science Sittings

New Zealand Tablet, Volume XXXVI, Issue 3, 16 January 1908, Page 35

Science Sittings

By^ 'Volt' n

• Seasoning Wood. Wood is seasoned by placing it in a solution of resin and soda and subjecting it to electrical influence.- The sap is drawn out, and the * solution enters the wood, which is then dried artificially. Wood can thus be ' seasoned ' in three days. To Engrave Egg Shells. Make the drawing of any figure or design you plcaise upon the egg, in melted tallow or thick oil. Then immerse the egg in strong vinegar. , After some time in the vinegar it will be found that the parts, untouched by tallow have been eaten away, leaving the design in relief. Bee Comb. Bee comb or beeswax, the material of which, the honey cells in the beehive are composed, is a wax - produced by a system of chemistry carried on in the 4 wax pockets ' which are located in the abdomen of all i working bees. It is a peculiar substance and is said to be analogous to the fats of higher animals. Originally it was supposed that this wax was taken up in an almost pure state from the flowers by the bees, but recent experiments carried on by the leading bot- " anists and chemists of the world conclusively prove that the bee is cap,abie of elaborating his peculiar wax, although confined to a diet purely saccharine in. its nature. The Barometer. That the barometer should be so important a factor in indicating meteorological conditions is to. many an unsolvable mystery. There should, however, be no difficulty in understanding tbat the simple principle underlying" the construction is that the free and unfettered air balances a column of mercury, varying in height, according to the circumstances of the moment, whose average elevation at the level of the sea is thirty inches. It is known, because directly ascertainable, that thirty cubic inches of mercury weigh - close upon fifteen pounds avoirdupois, and therefore, as commonly expressed, the pressure of the atmosphere is, under normal conditions, .fifteen pounds on every square mch — equivalent to nearly a ton on a square foot, more than eight and a half tons on a s'qiuare yard and of 100 tons on a square of ten and a quarter feet side. Scientific calculations also place the aggregate weight of the atmospheric envelope surrounding the world at about 5,000,000,000,000 of tons, and this may be represented as the weight of a solid leaden ball having a diameter of sixty miles. Such figures are really beyond human comprehension. The Latest Wonder of Electricity. In engineering works the electro-magnet is taking a very prominent place. This device dispenses with hooks, slings, and other lifting apparatus. By throwing a switch controlling the current, the magnet is energized and thereby attaches itself to the bars, castings, scrap, or pig iron which it is desired to lift. The magnet poles are shaped according to the nature of the material to be raised. For heavy rails they are oblong, and are slung from the crane hook by a short chain. Castings weighing over two tons are successfully handled by electro-magnets. Another use to which the electro-magnet is put is in breaking, old castings so that they may be melted and utilized. To accomplish this the magnet is made to lift and drop a steel ball weighing from one to six tons. The time lost in an engineering shop by what is known as sling- - ing pieces is saved by electro-magnets, connection being made instantaneously, and the weight liberated in the same expeditious manner. The magmet'is lowered to the object needed with the current turned off. When the switch is closed the magnet, becoming active, holds the articles to be lifted while they are raised and transported to their destination.. When they are lowered,, the switch is opened and the magjnet immediately releases them. As the operator of the crane controls the- action of the magnet through the switch, this one • man can attend to all the details of transferring heavy metal objects. No assistant is needed to attach them to the conveyer or to release them when they reach their destination.

Some idea of the mass of correspondence which Members of Parliament are called upon to. deal with may be gleaned from the following, fad»s relating, to the past Session. No fewer than 780,000 letters' nun. packets had been posted at the House of Commons post-offi.ee, and 1,087,45,0 delivered.; .