Page:Science vol. 5.djvu/416

 [Vol. v., Nf>. US,

��EKperimeuts show that the prnsressive ai^celeration or the rhythm brings about the moiiifioalions rei)re- «<) in the following table. The acceleration of rhythm from slzly to eight; atejM per i

���Francis Ei.oar. professor of naval architecture at the UniTcrslty of Glasgosr, devoted his inaugural address, on entering upon his duties in November, o a history of the science.

Until within comparatively tew years hut little at- tention has been paid to the study ol naval architec- ture. Fifty years ago tiincly-ninfl per cent of the British merchant-ships were under five hundred tons, and fpw measured more than a hundred and thirty

��feel. They were coinparalively uniform; and, being built after an established plan, they were perfectly seaworthy when properly balla9ted. In the case of war-ships llie matter was more difScult; as It was necessary to get a type of ship whirh should be \B.Tge, high out of water, and able to carrymany l.ii^ guns, without Interfering with lier sailing-cjuulltles, or ren- dering her top-heavy.

In 1811 ft school of naval architecture was started in England, and during twenty years it traineil forty students. This was followed In 1818 by another at Portsmouth, and In 1861 by a third at South Kensington, which Is now united with the Royal naval college at Greenwich. Sonie excellent designers have been graduated from these three schools.

Before the use of iron, ship-bullditig required no elaborate calculations: it was simply a highly devel- oped mechanical art Ships were built of great rela- tive depths in proportion to their breadth, and Initial stability was deliberately sacrificed to rednce the tonnage measurement. Usually these ships would not stand up, when fnlly rigged and light, without ballast; and, judging from the proportions given to them, they must also have required ballast when laden with cai^oes which were not composed of heavy dead-weight What Is now required of the ship- builder is to predict with great aucuracy the weights of complicated Iron and steel slructures, with all their Iittings and machinery; the weight of cargo that such structures will carry at sea; the stablltly they will possess In dlSerent conditions of loading, and the treatment necessary to insure a safe amount of stability being preserved upon all occasions;, the amount of steam-power aiid the rate of coal-consump- tion required U> maintain given speeds at sea; and vary frequently the strength that is possessed by the hull to resist the stralning-actlon of waves.

The reason that the English schools tor this study have not been better attended, is that the courses are too technical In character, and the requirements too rigid, to attract any except advanced students. The Idea of the newly established chair of naval archi- tecture in the University of Glasgow is to teach In a less technical manner the new science, and to adapt the course to the requirements of the students. The policy will be first to fix what they already know, and then to go forward to a compleU study. Special stress Is to be laid upon long-continued and arduous prac- tical training, combined Willi true science. Theoniy way in which superiority In shlp-Uulldlug can Iw at- tained is by possessing a class of ship-builders who have gone through just such a traiuing, and who by long study and work have acquired these theoretical and practical principles.

��RECENT BRITISH LOCOMOTIVES. Enqines recently designed for the London, Brigh- ton, and south-coast railway of Great Britain by Mr. Stroudley, were described by their designer at a recent meeting of the British Institution of civil e gineers. They were designed for freighl-l raffle, or

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