Science Siftings

New Zealand Tablet, 6 April 1911, Page 643

Science Siftings

BY 'VOLT'

Artificial Sapphires. News comes from Paris that at last artificial sapphires have been produced, after many unsuccessful experiments. Artificial rubies are now an old story. The artificial stones have all the properties, chemical, physical, and optical, of the natural gems. The only way in which experts can detect them is by finding them too perfect, as the natural gems have microscopic irregularities and enclosed imperfections that are absent from the artificial product. The stumbling block in the making of sapphires has been the color. Either the experiments could not produce the desired blue, or the stone would have a crystalline structure that made its detection easy. Now, however, M. Verneuil has submitted to the Academy of Sciences stones which he has made, colored with oxide of titanium, which, after a severe examination, are pronounced identical with true sapphires, though it is just possible that cutting them in gem form may reveal some irregularity of reflection or refraction.

Cane-Sugar in India.

India is the greatest cane-sugar producing country in the world, the country's crop amounting to 4,000,000 to 5,000,000 tons. Notwithstanding this fact, its sugar market has been captured first by the beet sugar, and later by cane sugar from Mauritius and Java. This condition of affairs has been brought about because of the backward state of the Indian sugar-cane industry in the matter of machine appliances. It is estimated that with modern machinery and better organisation of the industry, India could produce 50 per cent, more sugar. Sugar-cane is a crop particularly well suited to the country, and in the matter of sugar production India ought to be an exporting rather than an importing country. The native mills are either the ' kolhu,' a mortar and pestle arrangement, in which the cane is bruised and pressed, or else wooden-roller mills, of which there are two kinds — ' gundi,' consisting of two, sometimes three, upright wooden rollers, and the ' belna,' used in the Punjab and made of two horizontal wooden rollers. These mills are hard to work and do the pressing very ineffectually.

Smoke-consuming Furnace.

At Carlsbad, Austria, a form of smoke-consuming furnace has been introduced which has been patented all over the world and has shown excellent results in practical use. The idea is a simple one, but so effective that the poorest quality of Bohemian coal, a soft lignite, may be used with a combustion of 84:7 per cent, and practically no smoke or soot. This invention insures a draft cf hot air driven down on the fire from above, beating back the smoke as it endeavors to rise and consuming it completely. The coal is placed in a feeding box and slides therefrom over an inclined grade to a flat grate, until the whole surface of the two grates is uniformly covered. The inclined grate is provided at its upper half with narrow air appertures like a polygonal grate, and at its lower half with wider longitudinal apertures. The flat grate likewise has longitudinal apertures. The fire is started on the flat grate and forms an intense flame jet which extends over the inclined grate to the flues. During this operation the coal on the upper half of the inclined grate up to the feeding box gives off its gases and slides gradually downward on to the flat grate as the combustion on the latter proceeds, thereby continuously replacing the consumed coal. The necessary air is supplied to the grate through an air valve arid this can be regulated in accordance with the degree of heat to be attained.

Improvement in Sleeping Cars.

An improvement in sleeping cars that will appeal to the travelling public consists in the addition of windows in the upper berths. The construction is such that the berths can be swung and locked to the sides of the car. It is not intended that passengers shall be seated in these compartments except just before retiring and after arising. The two berths in each section occupy the full length of 6 feet 5 inches between the cross partitions of the car. Each berth is hinged to the side framing of the car, and its weight is balanced so that it may be folded up against the windows. Some of the advantages that this new type of berth is said to have, as compared with Pullman construction, should claim the appreciation of the passenger. The features of cleanliness and sanitation are important. And in addition to these a passenger sleeping; in a lower berth may, when arising in the morning, fold his berth against the wall and have the entire floor space and room below the upper berth for dressing. A neat leather-seated folding chair is stored under each berth and available for use when the berth is lifted. A novel feature for the convenience of passengers is the installation in the side wall at each berth of a plush-lined steel locker provided with a Yale lock. The locks are so designed that two keys are required for opening. A master-key will be carried by the car conductor and each passsenger will be provided with an individual key for the box in his berth. These keys will be attached to rubber rings, so that they may be slipped over the wrist at night,