Science.

Wairarapa Standard, Volume XX, Issue 2030, 25 February 1887, Page 2 (Supplement)

Science.

Welding by Elcctriciiy. Acem'ding to the ricul II erW, Profess ir Eiihu Thomson, u£ thoThomson-Hous-ton Electric C mpany, has invt nted a'method by which metal wires can be welded together without the application of external heat, but simply by pa-siug strong currents of electricity between the joints of the two pieces to be welded. The apparatus used is exceedingly simple, ami consists of a pair of metallic clamps, by menus of which the ends of the wins are gripped and held so as to touch each other. The clamps are made of heavy section, so as to be go ,r| conductors, and are elcclrieaily joined by a spiral of a few tarns of thick copper bar, which forms the sccondry coil of a transformer. The core of this transformer consists of a circular ring of iron wins, and the primary coil occupies about a sixth part of the circumference. It is wound in the same way as the coils on a (irauune ring. A machine producing alternating currents, and a suitable rheostat, by which the strength of thecurrentcan be varied, complete the apparatus. Since the secondary coil and the heavy metal clamps present hardly any resistance in (he secondary circuit, the current therein is very large, and raises to a high temperature the protruding ends of the wires to he welded, so that, practically, the ends fuse togather. Professor Thomson states that his invention is not confined to copper wires, but is also applicable to other metals, viz.. Herman silver, steel, iron, and brass. Some borax or other llux may be used, but it is not essential. The advantage of electrically welding joints on this principle is that Urn joints arc homogeneous, and of the same thiekm ss as the rest of the wire. Where the conductors to be Soldered together are largo, as in E li.soii mains and all mains for direct supply.uncof the main difficulties has been that the i xternal heat applied to the joint runs back along the conductor and into the protecting tube almost as fast as it is applied, thus making the operation very tedious. With Professor Thomson's apparatus no such difficulty need be expected, even when joining the heaviest bars, as the. heat is localized to the fraction of nn inch on either side of the joint. The invention should also Ire very valuable in joining the ends of steel band saws, as the metal need not be healed along any distance on either side of the joint, tints keeping the temper and finish of the saw the same. When the pieces are very large. Professor Thomson suggests the us-; of outside heat in addition to the heat applied electrically.

A New Material for Railroad Ties— A foreign technical paper, with an unpronounceable name, says that a now and important application of ozokerite has been recently discovered in Russia. It is now used for making ties on the Transcaspian Railroad, which has already pas-e l Oseliabat and nearly reached Mcrv. The process of manufacture is very simple and inexpensive. Kyra, the local name for ozokerite, is found there in thin layers of seven-inch thickne-s. In its primitive state, it contains a certain percentage of decayed matter. To remove this, the ozokerite is melted in large caldrons, the refuse sinks to the bottom, and the pure ozokerite collects at the top. This purified ozokerite, melted and mixed with 7d per emit, of limestone and gd per cent, of line gravel gives a very good asphalt, which is pressed in box s shaped like railroad tics. Notwithstanding the high t- mperaluiv. which re.iehai degrees R. (.1 In degrees Fahr.) the tiflfaetaiu their shape ami hardness. TlieiwHbliait ties are used ail along the roasLjnljfct at the ends and centre of ■MHpßnvnere as yet wooden tics arc emeconomised.

Vertical Wind Pressure— One of the strangest of cyclone freaks is recorded by a correspondent of the Pittsburg Jtiyiutch. The scene of it is at Washington Court House, 0., and concerns an •• apple tree with long spreading, heavy branches, perhaps extending to a height of twenty-live feet, iris a tree of perhaps twenty-live years' growth, an<l, undoubtedly, has roots as stout and almost as wide spreading as its boughs. Its trunk is not less than fifteen indies in diameter; it was a thrifty, vigorous tree without an unsound branch, and the family have for years driven their hi eh top buggy beneath its branches, for it shades the driveway into the yard. A short and stubby man cannot now walk under it without ducking his head. Docs the reader imagine it was uprooted? That might, indeed, seem possible, hut it is not true. Without breaking so much as a twig of its foliage, the atmosphere drove that tree right down two and a half or three feet into the ground. The hole enlarged about the base of the tree as it now stands shows how much larger is the base that has been forced beneath the surface.” A patient suffering from malignant pustule, died recently in (iuy’s Hospital, London. He was employed on a wharf, in handling of foreign hide's, and undoubtedly contracted the disease from the hide'it an animal which had been all'eeled with the disease known by the French as eharhen, by the Hermans milzbrand, but by English speaking people as anthrax. The patient noticed a pimple on the back of his neck, which intwenty-fourhours became greatly enlarged, and the glands of the neck were swollen. The surgeons removed the enlarged pimple at once, but without avail, the man living in about four days from the time he first noticed the pimple. This disease may also he contracted by the bile of an insect, a lly fur instance, which has been feeding upon the carcase of anjinfeetod animal. The microbe of the disease is a bacillus (bacillus authraeis), and was observed in the blood of cattle as long ago as ISP.t by IVllendrr. although its importance was first recognized by Uavaineiu l-SIO.

The passage Of the Suez (.'anal, which until recently occupied from thirty-six to forty-eight hours, can now be made in sixteen hours for vessels fitted with the electric light apparatus. This important advance is the result of a very interesting report by Commander Hector, of the steamer Carthage, belonging to the Peninsular and Oriental Company, and addressed to the directors. This report was written after the Carthage made the first continuous passage, under the authorization of the Canal company, given the first December ISS.I. The Carthage arrived at Suez after a run from Port Said of eighteen hours. The actual running lime was sixteen hours, there having been two delays caused by impediments in the channel; the mean speed being .VRi miles per hour. Boiler Corrosion M.M. Klienmul iierg have communicated to the Societe Chimique de Paris a note in which the;, state that the internal corrosion of steam boilers is grcally increased by the presence of organic matters in the water employed. This is not exactly news; but organic matters are fivipicntly placed in boilers to prevent incrustation and it is necessary to discriminate between those which are injurious and those which arc harmless. MM. Klein and Derg have discovered that sugars of all kinds intensify (lie action (they do that in ships), while glycerine and mannitu have no effect. Cheap Writing Paper—Paper of a very good quality can ba cheaply made of seaweed. The weed is boiled with carbonate of soda, and the filtered solution is treated with sulphuric acid, yielding a substance dial has more viscosity than starch or even gum arable, and that can be profitably employed in textile fabrics.