SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXXVIII, Issue 11686, 22 June 1901, Page 4 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

ELECTIUCTTY V. STEAM. It is only within the last five or six years that electrical driving in workshops Las begun to make way. The advantages over the old systen are so many and so obvious that there is no doubt that electrical distribution of power has come to stay. Protestor Crocker, of New York, enlarged upon these advantaged in a recent discussion, to be found in the Journal of the Franklin Institute. he first cost of the necessary equipment is greater, but not much greater, than the prime cost of shafting and bulling. Against this the depreciation and the cost of lubrication are less. New buildings will cost less owing to the absence of overhead shafting. Machines may be brought to their work, and need no longer be placed in a permanent position. Overhead shafting was dirty; electrical machinery is clean. In the Government Printing Office ;.■„ Washington the sick list is 20 to 40 per i i m. lower than before the introduction of electric motors. The authorities of the Baldwin Locomotive Works assert that if they had to re\ert to steam the cost of labour would be increased by 20 to 25 per cent., and their buildings would have to cover 40 per cent. more floor space. The plant at the printing office mentioned above cost 50,000d015. It shows a total annual gain of 16 2-3 per cent, on this sum. Taking 6 2-5 as the rate for, insurance, taxes, and interest, this gives a clear fain of 10 per cent, on gas and coal alone. As for space, the new system permitted of the addition of no fewer than forty printing presses on the old ilooi area. The increase in production was 10 per cent., and the net gain will pay for the whole plant in live years. It is thus seen that it is really in the indirect ins that electrical driving has the pull over steam, quite apart from the economy of power. Thesa tacts are sure to tell. VITIiniKII QUARTZ. Mr. 0. V. Boys was, we believe, the first to point out the value to the physical laboratory of "quartz fibres.'' These fine threads of melted silica possess enormous strength in proportion to their sixe, and amongst other desirable qualities have great elasticity and insulating power. Up to the present it bus not been found practicable to make vessels of silica except of small size. Mr. W. A. Shenstone. in his lecture at the Royal Institution, announces that a process lifts been, completed which will allow of vessels of silica, hundreds of limes larger than any made in recent years. The vittilled silica can be cut trod polished like glass, and. being harder than glass, is less subject to abrasion. It is as transparent as gins'; to the ordinary lays of the spectrum, but it also allows the ultra-violet rays to pass.

most of which ordinary i_'l;'.ss tibsorh I *. It takes lOOOdeg. C. to soften It: in fact, itis only moderately softened at a temperature which will [use platinum. The most remsrkablc of its valuable properties is its indifference to changes of temperature. Rods, tubes, and oilier vessels- of silica may be safely plunged at red or while heat info cold water without fear of fracture or other injury of any kind. tiiky LIVE ON sTAit-mrsT. Is it possible for any living creature to pass from one planet to another? Scientists now say that it is not only possible, but that i minute living creatures have actually reached I this world from other worlds hundreds of j millions of miles away. Every year hundreds of tons of matter caTied star-dust are j attracted to the earth. This star-dust con- j sists of small meteoric fragments, which have been hurtling through space until they have been drawn toward:-- our planet, like ironfilings towards a magnet. Many years ago it was suggested that the lowest." form of life ! bacteria might have been brought in this j way; but it was thought that the intense cold of space - otild have made it impossible. Experiments with liquid air, however, have shown that the lower forms of life are aide to survive the intensest cold. Temperatures of 300 degrees below zero do not kill them. After exposure to such cold, they begin to multiply again as soon as placed in favourable conditions. i JirSTS AND TIIKIK COMPOSITION. The phenomenon of dust showers, or : blood-red rain, so recently exhibited in ! Italy, is by no means unprecedented. About ; the middle of the eighteenth century, dust, ! to the depth of an inch in man}' [daces, I covered an area of ISOO square tail'-- _'tt the j North of Italy. Most of this dust, no i doubt, is transported from the dried Idas j or riverbeds of North Africa. Ehrenbere (Passat-Staub und lihit-Regen 1847) was led by microscopic examination to believe that it had come across the Atlantic, inasmuch as it- contained diatoms of South American species. Nordenskjold made an exhaustive examination of dusts on Greenland surface ice. lie divided ihe'-e dusts into three classes, one containing diatoms, and a second consisting of siliceous sua!, The third class contained metallic iron, cobalt, phosphorus, nickel, silicon, and carbon. Most of these elements are found combined in iron meteorites, and very rarely in terrestrial matter. ITeiue-he concluded that cosmic dust of this nature is continually falling on our surface. Professor Hartley and Mr. Ramage have been for some time making a detailed spectrograph ie examination of dusts,, terrestrial and celestial. They find that dust showers in Dublin (November 16, 12. 1897) contained matter akin to that of meteorities. The dust collected from hail, snow, sleet, and rain is regular in its composition, containing the same proportions of iron, nickel, calcium, copper, potassium, and sodium. Volcanic dust shows bands of lime and magnesia., with strong spectra of the alkali metals. The dusts from flues of gas, iron, copper, and sulphuric .acid works all contain quantities of rubidium, gallium, thallium, and indium. Nickel and manganese are also present, with more lead, silver, and copper than in the other types of dust. Domestic dust and the soot, from the harm- ' less necessary chimney contain more lime than does dust, of celestial origin. Manganese, copper, silver, and lead are constant constitufpnts, together with nickel, the latter probably being due to its presence in coal. A nRKAKFAST TABLE BAROMETER. When talking over the plans for the day over breakfast, one naturally wishes to know what sort of weather one may expect to have, and a cup of hot coffee forms a handy barometer. Drop in a hoop of sugar, and watch the bubbles rise, without disturbing the coffee. If they collect in the middle, the weather will be fine; if they adhere to the cup, forming a ring, snow or rain will fall ; while if they separate, but do not assume any fixed position, changeable weather is to bo'expected. gasf.ous DIFFUSION. It is not uncommon for a, branch of one science to assist the development of theories in a branch of another science. The relations between every section of physics and the science of mathematics are well known. The connections between chemistry and physics are sufficiently intimate. Astronomy is evei appealing to mathematics, nor does it a] peal in vain. Put it is comparatively tare for biology to have to appeal to physics, and rarer still foi physics tc benefit from the consequent investigations. The problem of plant nutrition has been productive of this unusual result. Dr. lit own, in a Royal Institution lecture, explains how the treatment of this problem has led to an extension of the laws of diffusion of gases. It has only recently been discovered flint the minute quantities of carbonic acid in the atmosphere enter the plant to perform their function of nutrition by minute openings known as sinmales. This fact in itself was a valuable find. But as the total area, of the stornates is but a fraction of the leaf surface, it was that the rate of entry must be prettyhigh. Experiments and inference showed that this rate is 50 times taster than if each stomate were kept filled with strong caustic alkali solution. Accepted theories could not explain this. But it was found that the rate in a cylinder varies inversely as its area of cross section. And if the line of flow of the gas were obstructed by a thin diaphragm pierced with a circular hide, the smaller the hole the more rapid the rate. This afforded an explanation of the rapid manner in which the thirsty stoinatc relieved its craving. And —for stornates —.his has proved to be the best, of all possible worlds, toi they are arranged on most leaves at a distance from each other which has proved to be ideally the most economical. 'Many interesting illustrations were given by Dr. Brown. The remarkable analogies between the stream lines followed by a diffusing substance and the distribution of electric potential around | electrified bodies within each other's sphere of influence were, it obvious, tit any rate ] suggestive..