SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XL, Issue 12225, 21 March 1903, Page 4 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

SUNLIGHT IN THE SEA.

The question of how far does sunlight penetrate beneath the surface of the sea has often been discussed without arriving at any definite conclusion. However, the query has at last been solved by the camera. The most sensitive photographic plates were exposed at various depths, with the result that it was ascertained how much sunlight • there.is in the water with each descending foot. There is a point at which no action of light is found, and that point is 600 feet under the surface. Below that is absolute darkness. RADIUM, THE NEW METAL. A pinch of radium, the new metal, and the most costly of all, has been sent to St. Petersburg, and a correspondent writes that the tests made with it at the Electro-Tech-nical Institute by Professors Mendeleieif, Yegorofl, and Borgman have led to results which promise a complete revolution in science. "The theory of light," he continues', " seems to be a false one.'' Among the scientists in England who are working on radium is Professor Sir William Orookes, who was good enough recently to give some interesting particulars regarding it. Radium is a very rare mineral found in " pitchblende" in small quantities all over the world. The chief source of supply is a Cornwall mine. Probably a ton of pitchblende does not contain more than a gramme (15£ grains) of radium, and it is extremely difficult to extract. Hence the cost. The infinitesimal quantity called a milligramme costs Bs, the gramme costs £400. and ix kilogramme (2.20461b) would run to £400,000. But there is not so much in existence. " A great deal of scientific interest attaches to the metal," said Sir William, "and it has altered our views on many scientific points. I cannot agree that any experiments Have proved that the theory of light is wrong. Light is a vibration of the ether as much now as it ever was." The metal has many curious properties and dangers. " Probably," he continued, "if half a kilogramme were in a bottle on that table it would kill both of us. It would almost certainly destroy our sight, and burn our skin to such an extent that we should not survive. The ; „ smallest bit placed on your arm would ' raise a blister which would take a month I to heal." Finally, radium emits electrons $. at such an enormous velocity that "the en- | ergv of one gramme of electrons is- enouph to 'lift the whole of the British fleet to the top of Ben Nevis. And lam not quite certain," added the professor, with a smile. " that we could not throw the French fleet in as well.'' The new metal must always be a laboratory subject, but experiments with it may lead to many important discoveries. A NEW ELECTRICAL DISCOVEBY. Professor Braun, of Strasburg, announces that he has made a great discovery with regard to wireless telegraphy, having found means to produce electric energy in unlimited volume, which can be projected into space in the form of electric waves to any distance. This new method, he assert", secures increased accuracy of transmission, and promises to lead to a. method of confining the current to the direction in which ft is sent, so that the possibility of messages being intercepted will be much re- . duced. IK MAES HIT US. Our world is spinning through space at a speed of over 1000 miles a minute, says an astronomer. Should it come into collision with a globe of equal size going at the same rate of speed-, what would be the result? The very best thinkers of the age tell us that heat enough'would be generated by the shock to transform both of the colliding bodies into gigantic bails of vapour many times their present circumferences. Some have thought that, in case the centre of the earth is composed of solid and colder matter than is the generally accepted belief, this might not be the case ; but after searching all the leading authorities it must be admitted that there cannot be found a more appropriate "finis" than the following, which is from an eminent scientist: —Should such" an unheard-of event occur the heat generated would be sufficient to melt, boil, and completely vaporise a mass of ice fully 700 times the bulk of both the colliding worlds—in other words, an ice-planet 150,000 miles in diameter. OIL FUEL. Mineral oil, wheih, being liquid, is one stage in advance towards combustion, has many obvious advantages as regards cost, economy of space, and handling, etc., especially for steamships, saving stokehold staff, and weight. It is used exclusively on the river fleet of steamers on the Volga, and, to some extent, by the Russian, German, and Italian navies. On the South Caspian Railway, 1600 miles m length, no other fuel is used. In the United States'the South Pacific Railway has 300 engines fitted to burn oil, and its use on railways in America is extending. In this country, the Great Eastern was the first railway to burn oil fuel on a large scale, and others of our railways are following the example of the Great Eastern.—Engineering Magazine. ' AN IMPROVED AUTOMOBILE. An automobile, in which there is a total absence of belts, chains, or gearings, has been designed two New Yorkers. C. J. Dorticusand E. W. Schneider. The only noticeable feature of the vehicle is the con- . struction of the wheels, each' one of which contains an electric motor in the hub. The current is supplied from a dynamo hidden in the seat of the carriage, and driven by . an oil engine. One of the advantages of this system is said to be that there is almost no occasion for a vehicle becoming stranded on the road. Even if three of the motors should become disabled, which is almost out of the question, except in case of a smash up, the one remaining motor is sufficient to bring the carriage home. The vehicle is steered by shutting off the current to the wheels on one side while it is applied to those of the other. ATHLETICS AND INTELLIGENCE. Professor Karl Pearson, F.R.S., stands kneedeep amid sheaves of statistics. His investigation of the correlation of the mental and physical characters in man has been necessarily prolonged by reason of the immense mass of anthropometric measurements and other data that has accumulated. It will take years, he says, to exhaust all his facts in discussion and publication, but every now and then he gives some of the conclusions arrived at. Three ladies—Miss Alice Lee, Miss Beeton, and Miss Lewenz— are, it may be said, associated with him in most of the inquiries. The material is based on statistics obtained among hundreds of Cambridge undergraduates, supplemented by a series of school measurements, and Pro-' - fessor Pearson has lately given the results of the preliminary work on the vexed question of the relation of athletics to 'health and intelligence. Tables have been constructed setting forth the statistical relationships which obtained between the health and intelligence (ability) of 2253 boys, health and athletics of 1743 boys, and intelligence and athletics of 1703 boys. In each category, of course, classes were established, such as " strong,", " delicate." " quick," "intelligent," " slow," very dull," and so on. Similarly, he has made at table based on 1664 cases, showing the percentages of athletic to non-athletic boys for the tempers, " quick-tempered," " good-natured," and "sullen." Schoolmasters may ponder and boys take heart of grace. The athletic lad is popular and noisy, although , popularity is not directly correlated with noise. He is slightly - self-conscious, and his temper tends.to be quick rather than sullen. He : is considerably more intelligent than the non-athletic. School life, in short, furnishes absolutely no statistical evidence for such : expressions as "the flannelled fool at the wicket," to say nothing of "the muddied oaf at the goal."—Daily Telegraph. '',"•- . WIND PRESSURES. .. The fact is fairly well established that the wind pressure on the inclined roof of a house is greater near the eaves 'than.near the ridge, and, according to the Engineering Magazine, some experiments would lead us to .believe that there may even be a nega- : .tiye.pressare near this ridge. Experiments and observations have shown that there may be, and probably always is, ' a; negative • . pressure or upward suction over the top "/■''-.of a gasholder during a heavy wind. Every-' one is familiar with the, corresponding up- ;" ward; pull: exerted; by; a > strong.; wind on - an, *i; umbrella. -' • ■■■•..■.•'■ .