Progress in Science.

New Zealand Graphic, Volume XLIV, Issue 1, 5 January 1910, Page 45

Progress in Science.

Corrugated System of Ship Construction

THE interest of the shipping world has been aroused by a new departure from the ordinary lines of ship construction, as exemplified in the steamship “Monitoria,” which recently left the Hylton shipyards of Messrs. Osbourne Graham and Company ©f Sunderland. This vessel of 3,300 tons

marks a new development in shipbuilding design, being built upon what is known as the Monitor or corrugated system. For several years past experiments have been carried out by the Monitor Shipping Corporation of Newcastle-on-Tyne, to determine the best method of increasing the longitudinal strength of a ship without any corresponding increase of weight. To this end the underwater part of the hull between the light and load lines was corrugated for almost the entire length of the vessel. Continued investigation and experiment resulted in ascertaining the definite form of this corrugation, and at last it was resolved to test the system practically in a full-sized vessel. The Ericsson Shipping Company, of Newcastle on-Tyne, undertook to build a craft on these lines, and the •‘Monitoria,’' now on her first trip, wjjs the outcome. The vessel measures'279 feet in length by 40 feet 1J inches normal extreme breadth, increased by the Monitor projection to 42 feet, with a molded depth of 20 feet 7i inches. In the accompanying illustrations the forms of construction of the corrugation are clearly shown. The shell plating is swelled out in two places on either side longitudinally, the curve being somewhat flat, and the upper and lower edges curving gradually into the flat side of the normal vessel. The very important result is obtained in this design that the projections give considerable increase in the hogging and sagging strength, so that the stress on the material is reduced at both keel and gunwale. The construction of the Sides of the ship with these corrugations is rather an addition than a vital alteration of the main structural system, and it can be applied to any type of steamship. The builders elaim that the extra cost is slight; and the dead weight carrying capacity is increased from three to four per cent. The coal bill is reduced from 12 to 15 per cent for the.same speed; or, if the coal consumption is maintained as before, the speed of the ship with the extra dead weight is increased from 0.25 to 0.5 knot according to the size and class of the ship.

A New Zealand Steamer's Performance. The steamship Otaki, built by Messrs. Denny of Dumbarton, is the first merchant vessel to be fitted with ‘‘combination” engines, consisting of two sets of triple-expansion reciprocating engines driving wing propellers and a low-pressure turbine driven by their exhaust steam

driving a central propeller. The act of reversing the reciprocating engines closes their connections with the turbine, which is not reversible, and diverts their exhaust to the condenser. Otherwise t e Ot’aki is identical with the sister ships Orari and Opawa of the same company, fitted with reciprocating engines. On a recent round trip to New Zealand the Otaki made the same average speed aa her sister vessels with a coal consumption of 11 per cent less than their mean, and a water consumption nearly 20 per cent less, their boiler's being identical with hers. She also made a non-stop run of 11,669 miles, probably the longest continuous run yet made by a marine turbine. <S> <s> <s> More Valuable Than Diamonds. Once it was possible to buy radium at 8/6 a milligramme; now the market price is £ 18 a milligramme, equal to £500,000 an ounce. This was one of the striking statements in u very interesting speech delivered by Sir William Ramsay at the foundation stone laying ceremony of a new radium factory in Limehouse, an eastern suburb of London. The British Radium Corporation, which is going to extract radium from pitchblende found in the Trenwith mine, Cornwall, is believed

to be the first company in the world to attempt the production of the precious mineral on a commercial basis. It is one of the romances of science that the material in the old days was regarded by the Cornish miners as a nuisance, for it prevented them from obtaining copper from smelting. For a long time it was cast on the dumps or left underground. To-day the comparative value of crude pitchblende ore is far in excess of the gold quartz of Johannesburg or the blue earth of the diamond mines. •$> <s> & A Gurions Property of Minerals. Certain minerals exhibit the curious optical property known as asterism, 'L.at is to say, they show a star-shaped figure when light is reflected from them or transmitted through them. This is s?en, for example, in the star stone, a sort cf

sapphire, and in the star ruby. A note in “Knowledge” describes the asterism of mica. The photograph of a lamp flame taken through a plate of mica shows a six-rayed star, with six fainter radiations between. Outwardly star mien resembles the ordinary form, and shows the same phenomena under polarised light. Wh°n examined under the microscope, however, the star mica is found to contain fine needles of another mineral, and these are regularly arranged at angles of 120 deg. To these needles the star seen by transmitted light is due. <B> «► ♦ A Sign of the Times. Buenos Ayres, the name of which suggests palm trees and sunshine and the transaction of business with sub tropical leisurely haste, is getting sufficiently busy to demand subways. A 'bill is pending in the Argentine Legislature to authorise the construction of underground electric railways operating in connection with existing surface lines. $ ■s> Reconstructing the Siberian Railway. It appears that the Siberian railroad is beginning to show the inevitable re-

sults of the haste and cheapness with which it was constructed. The sharp curves and heavy grading have put serious limitations upon .traffic, and for great distances the reconstruction will involve an entirely new location. The road is to be changed from single to double track, and the officials are greatly regretting that the large and costly bridges were built to accommodate ona track only. On the level plains the double tracking will not be such a serious matter; but in the heavy cuts of the mountain division, and where the steel bridges over the wide rivers win liave to be rebuilt, the coat will be very high. ❖ » 4> Rapid Railway Travelling. Ip connection with the landing of the Cunard steamers at Fishguard in Wales,

At Great Western Railway cf Englanv has put on a new special train to London, which has been making remarkable time. On a recent run a train with a total weight of 300 tons was drawn b.y the nev engine “ King Edward ” from Fishguan to London, 261 miles, at an averagi speed, including one stop of four minutes of 61.2 miles per hour.