NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXVIII, Issue 8682, 26 September 1891, Page 4 (Supplement)

NOTES ON SCIENCE, MECHANI CAL INVENTIONS, ETC.

THE CHEMISTRY OK THE OCEAN.

The study of the 685 densities of tho water of the sea made during the expedition of the Challenger, and the report of 108 aeries, of which each extended from tho : bottom of the ocean to tho surface, the discussion of tho results of the deep sound* < ings obtained by the Pola in 1890, the various theories relative to the chalk formations by chemical action with the necessary intervention of living creatures, and, finally, ho different observations of oceanic analysis with which M. J. Thoulot has been occupied for several years past, relative to the existenco at tho bottom of tho ocean of two bolts of water, one in repose, and the other in motion, are all in accordance with the following hypothesis : The surface of tho ocean, submitted to climacteric changes, is in a state of heating and evaporation more or less intense, Iho variations which result in the real density and in the chemical composition of the waters joined to the mechanical action exercised by the wind, give in the place of horizontal marine currents those more or loss vertical, which cross between these where they overlie each other, with extreme quickness and in different directions. These together constitute oceanic circulation, which is c flee almost entirely in a very shallow belt, about 500 fathoms in depth. The substances, only slightly soluble, contained in tho waters of the seas, and brought to the ocean by the fresh waters which are far more dissolvent, attain, at a cor tain depth, their limit of solubility and form precipitates. Becoming solid, they descend vertically, penetrate into the still belt, and at last reach the soil at tho bottom. Surrounded by immovable water, they dissolve and increase tho proportion of salt contained in tho deepest stratum of tho water, and that immediately in contact with tho soil. They then spread, and with extreme slowness, increase the saline quality of the adjacent waters, and at tho same time extend to the stratum next to the soil is not saturated, and consequently continues to dissolve the new material which arrives without cessation. Tho submarine soil is then a kind of centre of chemcal activity, fed by fresh material from the surface, and radiating slowly toward the surface. NEW PBOCESS IN* IKON MANUFACTURE. A series of experiments wero recently conducted at the Crown Point Foundry, Leeds, according to tiio London Colliery Garden, with a new aluminium flux called Stephenite, from the name of its inventor, the late Mr. Stephen, of Birmingham. Tho patent flux, which is composed of alumina and emery, contains about 70 per cent, of alumina. In its natural state this tlux is not volatilisablo like the refined commercial aluminium, bub in a blast cupola, or reverberatory furnace, it gives off its metallic gases or vapours, which unite with the fusible iron, for which they have great affinity, and which acts as a condensing agent, whilst all impurities go to the liquid slag and are drawn off in the usual manner. Metal manufactured by means of this flux, it is claimed, will work equally well under tlio hammer with the most malleable wrought iron, and will harden up to Lho hardest steel. It is also stated that the metal will work over and over again, becoming hard or soft at the will of the _ operator ; and tests havo proved that in its soft state it will stand a tensile strain of 3S*3 tons on the square inch, and when hardened 48*3 tons per square inch. Another point upon which stress is laid is that tho use of the flux causes the iron to flow in a much more liquid state, and to remain in that condition a considerable time longer than by tho ordinary, process, thus preventing blow-holes and faulty castings. By means of this invention, the promoters affirm, iron founders will be able to make their own steel castings, independent of steel works, by simply smelting scrap steel in their own crucibles. In experimenting, the cupola was charged in the ordinary way with common pig iron and coke, and then the flux, which is in tho form of briquettes, was added. In duo course the molten metal v 'as run off, and several castings wero made. Some of these were immediately chilled, and examined by experts present, who considered the experiments had been successful. A TELEPHONIC SYSTEM FOR SHU'S.

A system has been devised by means of which a ship having a telephone installation on board can bo placed in connection with tho Central Exchange whenever it comes into port. A telephone is placed in the captain's office, and tho wire connecting with it is attached to a flexible cord, fitted with a conductor at the side of the boat, lhe wire leading from the exchange is brought down to a corresponding position on the dock, and is also fitted with a conductor. When tlio ship cotncs into port all that is necessary is to"make the connection, which is simplv done, and anyone on board can at once communicate with any of the business houses of the town. lUIUDKSCKST CLASS. Examples of ancient Cyprian glassware aro noted for their gorgeous irriilesccnce, surpassing in brilliancy of colour anything over produced by-artificial means. So far as is at present known, this effect can be produced only by the corrosive action of the air and moisture of the soil in which these objects havo been buried for centuries. A microscopical examination of this "lass shows that the surface is covered with° exceedingly thin transparent films formed by matter dissolved from the glass. The body of the glass is pitted over its entire surface with minute cavities, which are circular, elliptical, or oblong in outline, and either spherical, ellipsoidal, or cylindrical in respect to their concavity, and the films confoim to the pitted surface of the "lass. These films, of which there are many superposed, are so thin as to float in air like down when detached. They decompose the light by interference duo to reflections from the front and rear surfaces of the film, and give rise to the gorgeous play of colour. THE END OK Til TSETSE FLY.

The latest news from South Africa (says ! the Daily Graphic) is that a Natal man is so confident of having discovered a remedy against the tsetse fly that he has accepted a'contract to transport the Portuguese military stores through the infected district on the backs of bullocks. If ho has, that Briton is worthy of a monument as big as Table Mountain ; for ho has removed the only great obstacle to the settlement and civlisation of vast regions, where tho ono pest, is not fever, or Kaffirs, or heat, but the bite of an insect not larger than the house fly, and not unlike u. Harmless to man, large game, goats, and apparently all animals while suckling, it is death to horses, oxen, dogs, and in most cases to donkeys. A. few days sufiicc to end the life of the bitten boast. Ail examination of the body exhibits tho, extraordinary changes which the speck of venom has wrought. Among other transformations, tho biood is thin, small in quantity, and so colourless that it will scarcely stain paper. No cure, no preventative of much value has yet been found. Lion's fat, and milk and manure smeared over the threatened victims modify the attacks. But inoculation has no effect. MISCELLANEOUS.

A medical journal states that five clergy men live as long as eight workingmen.

A ready way to cool a hot journal in machinery that cannot be stopped is to hang a short endless belt next to the box, and let the lower part of it run in cold water. The turning of the shaft- carries the belt slowly round, bringing fresh cold water continually in contact with the heated shaft, and"without spilling or spattering a drop of water. A substitute for emery in grinding has been found, it is said, in crushed steel. Highly tempered steol is heated and plunged into water. This renders it so brittle that it can be pulverised, and in this shape it has been found to do the work of emery better than the genuine article. A bulletin of aluminium, issued by the Census Bureau, indicates that this metal is gradually working its way into the indus trial economy of the people. Large deposits of the ferruginous hydrates, from which the metal may be most cheaply produced, have recently been found in Arkansas, and aluminium roofing, pipe, ornamental work, bridges, and the like may not be so far distant. The French manufacture a paper linen so cleverly that it is almost impossible without examination to detect the difference between it and damask ; and even to the touch the articles made of papier linge are very much like linen, and are used for many purposes to which linen is applicable. *