Science Siftings

New Zealand Tablet, 1 June 1911, Page 1027

Science Siftings

BY ‘VOLT’

A Pitch Lake.

It has been estimated that the Great Black Pitch Lake of Trinidad yields annually 80,000 to 90,000 tons of asphaltum. Dimensions of Ocean Waves. Dr. Vaughan Cornish recently communicated to the Royal Geographical Society his estimates of Jhe dimensions of ocean waves. With a heavy gale blowing tjjese reach a height of 42 feet in any position ij*)t less than 600 nautical miles from the windward shore. In his report he exonerates of any exaggeration sea captains who have reported waves of from 80 to 100 feet in height, by stating that they reported the altitude of large waves of broken water flying aft from the impact of the steamer’s bow on a head sea. Rubber from the Banana Plant. The constantly increasing demand for rubber and the exorbitant prices now placed on this product have led to extensive experiments in regard to the extraction of rubber from the juice of the banana plant. Thus far it has been established that there is a yield of a thick and pliable rubber, which, when compounded with other rubber, has a distinct value in that it increases both the weight and the elasticity of the rubber with which it is compounded. Petroleum and Plant Growth, A recent study of the action of petroleum on plant growth has disclosed some very interesting results. The experiments were made with a 10 per cent, solution of the oil -in plants of stramonium and plantain. No injurious effects were noticed except in cases where the petroleum was allowed to accumulate thickly about the roots, thus making it possible for the roots to absorb the oil and so drying up the soil as to prevent absorption of moisture. Nor was any direct poisonous action of petroleum detected like that which it exerts on animal organisms. Putifying Rock Salt. Evaporation has heretofore been the. commercial method of extracting pure salt from rock salt. This cleansing required one ton of coal per ton and a-half ■yield of salt. A more economical process is now used, which makes it possible to manufacture fifteen tows of salt with one ton of fuel. The mine salt is placed in a furnace, where it is readily converted into a molten mass. Thence it is run into a container, through which a current of compressed air is forced. All impurities are thus blown off or precipitated. The molten salt is then moulded off and allowed to solidify. A Remarkable Effect. Perhaps the most striking instance to be seen In the whole world of the wonderful apparent coloring of bodies of water is the marvellously beautiful ‘ Blue Lake ’ in Switzerland. Encompassed on all sides by lofty mountains, their lower ranges luxuriantly clothed with verdure down to the edge of the water and adorned with many fine forest trees, while their higher acclivities are garbed in a mantle of eternal snow, the little lake, nestling in its deep hollow basin, and protected from winds and storms, is quite startling in its singular and strange beauty. The water, although really pure and colorless, appears to be of a most vivid and intense sky-blue. And its transparency is so remarkable that a small nickel coin dropped into the water in the centre of the lake can be seen gyrating downwards until it reaches the bottom, apparently more than a hundred feet beneath. The Detonation of Large Gems. A. recent Italian invention offers a unique and at the same time effectual protection to gunners against possible injury to the sense of hearing consequent on the detonation of large guns. The muffler consists of a solid mass of glass of such dimensions as to fit snugly the external meatus, into which it is inserted. A perforation traverses it horizontally, the inner end of which fairly reaches the tympanum. The outer end of this passage does not quite extend to the external surface of the glass, but joins with a second bore running in the vertical and communicating above and below with the atmosphere. With every violent concussion an aspiration is caused in the horizontal passage, with a subsequent rarefaction of the small body of air cushioned between the ear-drum and the glass protector. This attenuation of the air greatly reduces the aerial vibration. The sensitiveness of the ear for lesser sounds is not diminished, as the atmospheric compressions produced are not effectual in causing rarefaction. This invention is a neat application of the well known principle of Sprengel’s aspirator.