SCIENCE NOTES.

Otago Witness, Issue 2437, 28 November 1900, Page 62

SCIENCE NOTES.

— The- Gouraudphone is an apparatus for i magnifying the sounds of a telephone, or • , phonograph, co as to be heard a long distance, after the mannei of a speaking trumpet, foghorn, or steam "siren." This is done by cans-ing the vibrations of the telephone disc i or the phonograph style to work a piston j valve controlling a current of steam, air, or .Other gas, entering a cylinder. The steam, ar - gas, thus controlled, works a larger piston in another cylinder, and this, again, another, until' the required force of. vibration is obtained, and may be turned into'audible sounds by means of a vibrating diaphragm resembling, that 'of a telephone, but larger. " It, is pro- - posed to use the 'apparatus at lightships and lighthouses by way of a talking "siren." — The great railway tunnels of the Alps ranlfl among'-the mosV important engineering triumphs of the "century. Mountain tunnelling on a large scale Has special difficulties of its own; arid the mariner in which these" were -solved by the engineers will always be interesting. TEe present existing Alpine tunnels are three in number — the St. Gothard{9£ miles), the Mont Cenfa (8 miles), and the Arlberg (6 1-3 miles). The first named is at present the largest railway tunnel in the world, though a new one is being driven through the Simplon which will — when completed—exceed 12 miles in length. The St. Gothard tunnel was 10 years in the making, arid -cost the lives of 600 men, including the engineer and contractor; for such a work is extremely dangerous jo health, and that for several reasons. Everyone knows that as we ' descend below the surface of the ground, the temperature steadily rises; a large part of the tunnel, therefore, being 5000 ft below the ground oivtside, has the. high temperature of 85'deg Fahr. from year's end to year's end. Moreover,,. the atmosphere is extremely damp, .t. t so that the work has to be done under conditions approximating to those of an equatorial fores! On the other hand, when the workmen 'start for their homes, they pass in a few minutes from this hot, moist region to the regions of an Alpine climate, at an elevation of 4000 ft. In addition to this danger, the necessarily poor ventilation of the unfinished tunnel is a constant source of "peril to health* It is satisfactory to note that some of these dangers And' difficulties - .have*, been * greatlyxeduced in the 'case "of *the v Simplo"n* tunnel. - The . ventilation there is .'.said 'tc be no less than 50 times better than- that supplied in the. St. Gotha'rd; and special- "provision is made. ' for cooling the injected air by means of water jets. Moreovei, When the men leave their work they .pass from the tunnel into^a building suitably warmed; where they exchange • their working garments for warm, dry clothing,^ and. obtain a, good, meal before passing to the' colder" an outside. Their working ■clothes are left in the building to be cleaned '• and. thoroughly dried before being used again. Travelling through the Alpine tunnels was, till.wiihin the last .few months, a most unpleasant 'business, owing to the bad yentilation;, but now, tfiankg to the inveubioag of

Signoi Saccardo, ventilating fans of great power have been arranged to force an air current right through the St. Gothard tunnel. The efficiency of the new arrangement was proved at its first trial; before the fan was started, the temperature was 107deg, and the moisture 97 -per cent. — abo,ufc the state of things in the Red Sea during a very bad passage — but in a few minutes after starting the fan the temperature fell 26deg, and the smoke and damp were blown out. A similar arrangement will be applied before long , to the Mont Oenis tunnel. — A few particulars (says Engineering) about some of the few important Norwegian waterfalls may be of interest. The largest river in Norway is the Glommen, which at a distance of some 27 miles from Ohristiani^ forms v a number of waterfalls close to each other, which, over a distance of about half j a mile, have an aggregate fall of 64ft. Under ordinary circumstances the quantity of water amounts to lbO metres per second, but by rational regulation and exploitation of the Mjosen lake this quantity can be very materially increased, and a capacity of 5&,000-h.p. may be reckoned upon. At present there is a wood-pulp factory in the vicinity of the waterfall, which controls four-fifths of the power, or about 45,000-h.p. Two German experts have been called to Norway in order to give then* opinion as to the exploitation of the water power, and they are understood to have reported very favourably as to the conditions for erecting and making remuneraI tive a large power station. The new instalI lations will yield power to extended woodI pulp factories, sawmills, etc., in addition to which a calcium carbide factory will be built, and power transmitted to the town of Moss, some 15 miles distant. —It is rumoured, says Electricity, that Trinity House will adopt a new form of electrically-lighted buoy to replace the old bell and gas buoys stationed at various dangerous points along the Channel. The interior of the buoy is to contain a miniature ' electric light plant, the motion of the waves working the piston of an air compressor, which drives an engine and small dynamo. The • electricity thus generated either workß a powerful flash or fixed light, or is used to control an automatic syren apparatus. • — Keeley pretended to follow the lines (or lead them) of those who believe that the destruction of matter will" produce" oa-" create 'energy. On one occasion he undertook to. produce an almost unlimited horse-power for 9A hours by the destruction of three drops of water. . His machine for the above purpose was reported to be contained "in a sardine box." The experiment did not come off, owing to an "unexpected breakdown." He called the force which was supposed to drive his motor, "Apergy," and the apparatus itself "Vilrodyne." "Apergy," he said, was a hitherto unknown force consisting of xtremely rapid vibrations of ether, "or matter of infinite divisibility" ; but Mr E. A. Scott, of the Philadelphia Engineers' Club, who visited Keeley in the disguise of .n interviewseeking reporter, came to the conclusion that "Apergy" was an "ingenious combination of compressed air and electricity." "Platinum wires," which figured very largely in Keeley's apparatus, seem to have been in reality tubes for conveyance compressed air. On Keeley's death, a .horough investigation of his laboratory showed that the walls were used to conceal compressed air-tubes, and there is little doubt that he was an arrant impostor, and did not really follow any line of investigation at all. When openly examined by scientific men, he used to hide his I lack of any discovery by the use of interminable "technical expressions" of his own manufacture, which effectively prevented his visitor from following or understanding him. — The routine treatment of diabetes mellitus usually comprised the elimination of potatoes from the dietary along with other farinaceous articles of food; but, according to Dr Mosse, of Toulouse, the potato may be eaten with advantage as a substitute for bread in most cases of diabetes of moderate intensity, especially in the so-called arthritic cases. In a number of instances he found, indeed, that patients could take from two to three pounds of potatoes daily for weeks together, ' not only without inconvenience, but with positive idvantage in respect of the general health. Even in the diabetes of pregnancy some latitude is permissible in this respect, and when* one reflects upon the grievous discomfort and even, suffering which. curtailjMut

of the carbo-hydrates causes in such patients this permission will be welcomed. — A process for preserving y wood has been invented by a German, called the xylosete process, which consists in boiling the wood in a solution of metallic and mineral salts, under a pressure varying from 151b to 401b per square inch. The solution is composed of the sulphates of copper and iron crystallised together in the proportion of 80 per cent, of copper and 20 per cent, of iron, alumina, and a salt which is mined at Strassfurt, in Germany, called "kanit." This latter chemical is a compound of sulphate of potash and magnesia and chloride of magnesia. The properties that this solution exercises upon the woods so treated are the withdrawal of the sap and its dissolution with the liquid, the destruction of the germs of decay by the action of the copper, and a chemical formation by the iron, which is insoluble in water, with the cellulose or woody fibre. Several experiments have' been treated by this process neaT Vienna. The treated wood was utilised as props in the vineyards, and never displayed the slightest tendency to decay. Sleepers treated by this process have also been employed on the Bavarian Government railways, and it has been found that even the softest woods are rendered as strong and, as durable as oak by the solution. — Another electrical tuberculosis cure ds being tried with alleged excellent results by Dr O. O. Carroll, of New York. Dr Carroll, as nearly as can be ascertained, employs a Tesla oscillator, and >by passing currents of high frequency and high voltage through the lungs of a patient, in time causes the tuberculous matter to be eliminated from the system by the emunefcories. The claim is made for this treatment that even patients in the last stages may be benefited if not entirely cured. It is to be hoped, for the benefit of mankind, that such is the case, but in the light of other experiments of this nature it is to be feared that those interested in tbe discovery may possibly be too optimistic. That an electric current suitably applied in a ease of tiibereulosis in its early stages will prove beneficial has been proven, biifc that it can be made to- cure a patient that has but a few weks to live is hardly to be expected in the present state of art. — Electricity. — Professor Sylvanus Thompson gave a most interesting lecture on electricity in the industries at a recent meeting of the British Association, referring to the schemes for distribution of electricity "in bulk" that have recently engaged the attention of Parliament. He considered it of vast importance from a national point of view that there should bs available in every great industrial district a cheap supply of electrical power. We had to compete in the mechanical and chemical industries with firms in other parts of the world who could buy electrical power at less than a half-penny per horse-power per hour. The great power stations "of Niagara and Rheingelden were creating whple industries, and new communities, living under material and social conditions greatly in advance of those with whom they severally competed. England had not waterfalls, but she had a natural source of power in her coalfields. The direct line of economy, he urged, .pointed to the creation of electrical generating centres \ right at the pit's mouth, where the generating machinery would be driven by large steam, or, better, gas, engines. From such centres electrical currents would be distributed oyer whole districts, or even countries., to drive mills and! factories, and furnish light and power far more economically than could be done in a lot of little separate electrical stations, whether private, parochial, or even municipal ; but stich great undertakings could not be caried out without the employment of large capital and high technical skill.