The cylinders of the main engines are 22 in., 36 in., and 57 in. in diameter respectively, with a piston stroke of 3 ft.  The high-pressure cylinders are each fitted with a piston valve, and the intermediate and low-pressure cylinders with double-ported slide valves, all of which are worked by the usual double eccentric and link motion valve gear, by which the cut-off can be varied as required.  All the shafting is forged of Siemens-Martin mild steel of the best quality, each of the three separate cranks being built up.  The condensers are placed at the outsides of the engine room, and the air, feed, and bilge pumps are between the engines and the condensers and worked by levers from the low-pressure engine crosshead.  There are two centrifugal pumps, each worked by a separate engine for circulating water through the condenser, and these are so arranged that they can be connected to the bilges in the event of an accident to the ship.  In the engine room there is fitted an auxiliary feed donkey of the duplex type and made by the Fairfield Company.

This pump has all the usual connections, so that it can be used for feeding the boilers from the hot well, for filling the fresh water tanks, for pumping from the bilges, or from the sea as a fire engine.  The engines are arranged in the ship with the starting platform between them; and the handles for working the throttle valves, starting valves, reversing gear (Brown’s combined steam and hydraulic), and drain cocks are brought together at one end of the platform, so that the engineer in charge can readily control both engines.  The two sets of engines are bound together by two beams bolted to the framing of each engine.  This feature was introduced into the design for steadiness.

The method of supporting the propeller shaft brackets is interesting, and we reproduce a photograph that indicates the arrangement adopted.  Instead of the A frame forming part of the same forging as the stern frame, the Fairfield Company have built up the supporting arms of steel plates riveted together, as is clearly shown.  There is an advantage in cost and with less risk in undiscovered flaws in material.

An interesting change has been made in the steam pipes.  Cases of copper steam pipes bursting when subjected to high pressure have not been infrequent, and Mr. A. Laing, the engineering director on the Fairfield Board, with characteristic desire to advance engineering practice, has been devoting much attention to this question lately.  He has made very exhaustive tests with lap welded iron steam pipes of all diameters, but principally of 10 in. diameter and 3/8 in. thickness of material, made by Messrs. A. & J. Stuart & Clydesdale, Limited, and the results have been such as to induce him to introduce these into vessels recently built by the company.  It may be stated that the pipes only burst at a hydraulic pressure of 3,000 lb. to the square inches.

The Tynwald was tried on the Clyde about a month ago, and on two runs on the mile, the one with and the other against the tide, the mean speed was 19.38 knots—­the maximum was 191/2 knots—­and the indicated horse power developed was 5,200, the steam pressure being 160 lb., and the vacuum 28 lb.  Since that time the vessel has made several runs from Liverpool and from Glasgow to the Isle of Man, and has maintained a steady seagoing speed of between 18 and 19 knots.—­Engineering.