NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXV, Issue 9142, 25 August 1888, Page 4 (Supplement)

NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

IMPROVEMENT IN COMPOUND ENGINES. An improvement in compound engines and in valves employed therein has been patented. In this invention the loss of heat in the live steam resulting from the exhaust steam through the live steam ports and distributing valves of the hiph pressure cylinder is obviated by a special construction of compounding valves. The exhaust steam is thus caused to pass through a separate hollow compounding slide valve and set of ports direct into and through the lower pressure cylinders.

HANDY DEVICE FOR DETECTING GAS LEAKAGE. A handy apparatus for detecting leakage of gas from houi*s service pipes has been devised. It consists of a small pipe bent twice at right tingles, and connected with the service before and after the main cock. A small glass bulb, partly filled with a mixture of glycerine ana water, is placed on the pipe. A tube dips into the liquid in the bulb, and is so arranged that any gas passing through the small pipe bubbles through the liquid. The bulb is also provided with cocks at its inlet and outlet. If these latter are opened, and the main cock closed, and the burners shut off, any bubbles in tho liquid show a leakage of gas in the pipes or fixtures beyond. A DANGEROUS INVENTION. A Russian lieutenant of engineers has perfected an apparatus for intercepting telegraph and telephone messages in time of war. The apparatus is contained in a small oblong box and weighs rather less than three pounds. The telegraphic receiver is of the recording typo, anil a battery for returning false messages to the enemy forms part of the equipment. An invention of tho nature above described cannot fail to be dangerous in the hands of unscrupulous persons. APPROACHING EXHAUSTION OF PETROLEUM. It is estimated by Professor Lesley and others who have made a careful study of the petroleum supply that the American stock is now rapidly approaching exhaustion, and that within a score of years the accumulations of millions of years of geologic time will be practically used up. Up to the beginning of 1885 the quantity raised in the United States had reached the enormous total of 261,000,000 barrels. In 1885 the yield was 21,042,841 barrels. METALLISED WOOD. The recently invented process, says the Iron, by which wood is made to take on some of the special characteristics of metal, has been turned to practical account in Germany. By this process the surface becomes so hard and smooth as to be susceptible of a high polish, and may be treated with a burnisher of either glass or porcelain ; the appearance of the wood being then in every respect that of polished metal, having, in fact, the semblance of a polished mirror, but with this peculiar and advantageous difference, namely, that, unlike metal, it is unaffected by moisture. TO SOLIDIFY PETROLEUM. Dr. Kauffman, an Austrian scientist, has hit upon a method of solidifying petroleum and so permitting it to be used in ordinary furnaces for the production of steam —at once doing away with the employment of special apparatus- for its utilisation. The process consists in heating the crude oil with from 1 to 3 per cent, of its weight of common soap for from thirty to sixty minutes, at the end of which time the soap will be found to have amalgamated with the oil and so constituted a solid mass, of the consistence of tallow, which is then cut with wires into the shape of bricks without any difficulty. This can be used even in an ordinary grate, in the same manner as coal. It is tardy of ignition, but, when once fired thoroughly, burns slowly without smoke, leaving about 2 per cent, of black, colourless, odourless residue. Compared with coal it is stated that such bricks are consumed at a rate about one-third as rapid as coal is exhausted, and that the quality of heat produced is far superior to that derived from. coal. TEA AND TEETH. A correspondent of the British Medical Journal (Surgeon W. T. Black) makes the following interesting remarks on the injurious effect of tea on the teeth : —Some years since, when on duty at recruiting stations in the north of England, I took observations on the great amount of disease and loss of the teeth existing amongst the class of men offering themselves. It became a cause of rejection of itself in great numbers. As far as my inquiries went I was led to trace it to the excessive teadrinking indulged in by the working classes in the manufacturing towns, and this went on all through the day, whether with food or not. In fact, instead of five o'clock tea being the invention of the upper classes, it was found to exist to an injurious extent in the working classes long before that time. Tea seems to have a peculiar tendency to cause hyperemia in the tooth sacks, leading to inflammation, and, eventually, abscess of the fang, with, of course, aentralgia at every stage. Whether this special tendency was due to theine or tannin having an elective affinity for dentine, it is not possible for me to say. It would be curious to know if medical men, practising in such manufacturing districts, had observed the deterioration of teeth to be coincident with tea-drinking. THE WESTING HOUSE COMPOUND ENGINE. The Westinghouse Machine Company has issued a circular letter giving some results of tests made in connection with their new automatic compound single - acting steam engines—condensing and non-condensing. They say : —The results thus far obtained are almost as surprising to ourselves as to others who are conversant with the facts. The tests are still in progress, principally to obtain statistics at a higher range of steam pressures than has heretofore been available in our own works. In designing the new engines the aim has been to cover all the features now so popular in the automatic engines, and to add the following points, which are considered desirable : Ist. To obtain the recognised economies in fuel, to be had through compounding, without any complication or excessive cost, so that these engines can be placed on the market, in the strictly commercial sense, from the smallest size to the largest. 2nd. Practically .no more complication or mechanism than exists in the simplest engine. 3rd. A greater economy of fuel than heretofore obtained by anyone in engines of equal horse - powers. 4th. A complete and perfect control of the steam supply to both high and low pressure cylinders, through the medium of a single balanced valve. sth. The ability to maintain an absolute constant speed, under varying steam pressures and loads. 6th. The best results throughout, combined with the greatest simplicity and the least cost. MISCELLANEOUS. Edison has a contract from the Spanish Government to build a flying machine, to be worked by an electric battery on the ground, from which photographic views can be taken of the position of an army. In a German botanical journal, a new method of retaining the natural colours of flowers when put under pressure for preservation has recently been published ; it consists of dusting salicylic acid upon the leaves, and removing the powder with a brush when the petals are dry. Or the same acid may be used as a solution, one part of acid to fourteen of alcohol. Cotton-wool or blotting paper impregnated with the solution is laid above and beneath the flowers as they lie in the press. It is said that red colours in particular are well preserved by this simple process. The Railroad Gazette says that the mechanical construction of the bicycle is well worth study. The requisite amount of strength is probably obtained with a smaller proportion of weight than in any other machine, and considering the trying nature of the strains, a fair amount of durability is obtained. The price per pound, however (about 12s), of the best and lightest machines is considerably in excess of that of almost any other machinery. Dr. W. A. McCorn of the New York City Asylum for the Insane, has found hyoscymine, sub-cutaneously administered, a very useful remedy in quieting mania, and attended with less unpleasant symptoms than are chloral or the bromides.

An agent of the Forestry Department, Mr. Farris, has reached the conclusion that the rings on trees are not an accurate record of the ages of the trees. Mr. Farris lias found twelve rings in trees only six years old, five in those eight years old, and eleven those of only nve years. Seven varieties of fishes examined by naturalists of the Challenger expedition h<*ve been found to be totally blind in the deep soji, but can see when inhabiting shallop w^tftr.