THE SCREW STEAMER ANTHRACITE.

New Zealand Tablet, Volume VII, Issue 380, 30 July 1880, Page 9

THE SCREW STEAMER ANTHRACITE.

It is now many years since Mr. Jacob Perkins demonstrated the practicability of using steam at a very high pressure for the purpose of discharging bullets from a gun, by means of his steam gun, at the old Adelaide Gallery. Although the capability of steam for taking the place of gunpowder in this respect was then proved, the former has not yet superseded the latter in practice. Working still upon the high-pressure theory of Mr. Perkins, his descendants have followed up the principle in another and more promising direction— namely, xn connection with the steam engine. It has been left to the grandson of that gentleman, Mr. Loftcs Perkins, to develop the theory to such a high degree of perfection as to bring it satisfactorily within the domain, of practice. For several years past the Perkins system of using high-pressure steam has been in use both on land and in steam ressels with every .'ucces-s. The later instances, however, being more fully developed than the earlier, are naturally more perfect. The most recent example occurs in connection with a small vessel, the Anthracite, which is about to leave for America, and which is the smallest steamer tbat has ever undertaken a voyage of this length on her own unaided resources. The Perkins system consists of a tubulous boiler, in which steam is generated at a very high pressure, and a special system of engine in which the steam is used and re-used over and over again. The boilers are charged with fresh distilled water, a small quantity only being required, and this, after being converted into steam and used in the engine, is condensed and re-used. The advantages of the system are — a very small consumption of fuel, immunity from explosion by reason of the sub-division of the boiler into numerous parts, each part having a high resisting power, and durability of the boiler, which is equal to that of the engines and ship. The boiler is constructed of horizontal tubes, welded up at each end, and connected by Email vertical tubes, and is proved to 25001 b. per square inch. The engine has three cylinders of different diameters, the smallest cylinder being placed over that of medium size, and being worked from the same piston red. Steam is used at pressures ranging from 3001 b. to 5001 b. to the square inch, 3501 b. being the ordinary working pressure. — Times.