The slide valve box, F, is bolted to the cap-piece, B¹, as seen in Fig. 4.  As for the slide valve, t, its arrangement may be distinguished in section in Fig. 2.  Its eccentric is keyed at 170 deg. so as to admit steam into the small cylinder during the entire travel, which latter is 470 mm.

To permit of the expansion beginning in the small cylinder, Mr. Farcot has added a sliding plate, t¹, which abuts at every stroke against the stops, s.  These latter are affixed to the rod, S, whose lower extremity is threaded, and which may be moved vertically, as slightly as may be desired, through the medium of the pinions, S¹, when the hand-wheel, V, is revolved.  A datum point, v, and a graduated socket, v¹, allow the position of the stops, s, and consequently the degree of expansion, to be known.

Steam is introduced into the small cylinder through the conduit, i, and its passage into the large one is effected through the conduit, f.  The escape into the interior of the frame is effected, after expansion, through the horizontal conduit, h.  The pipe, H, leads this exhaust steam to the open air.

The pipe, I, leads steam into the jacket, C¹, of the large cylinder, this latter being provided in addition with a casing of wood, C squared, so as to completely prevent chilling.

The regulator, R, is after the Buess pattern, and is set in motion by a belt which runs over the pulleys, a and a¹.  It is mounted upon a distributing box, R¹, to which steam is led from the boiler by the pipe, r¹.  After traversing this box, the steam enters the slide valve box through the pipe, r squared, its admission thereto being regulated by the hand-wheel, R squared, which likewise serves for stopping the engine.

The cocks, x, are fixed at the base of the uprights, B, for drawing from the frame the condensed water that has accumulated therein.

The lubricating apparatus, V, which communicates, through the tube, u, with the steam port, r¹, permits oil to be sent to the large and small cylinders through the tubes, u¹ and u squared.

Mr. Farcot has recently adapted this type of motor to the direct running of electric machines that are required to make 400 revolutions per minute.—­Publication Industrielle.

* * * * *

IRON AND STEEL.

At the recent meeting of the Iron and Steel Institute, London, the president-elect (Mr. Bernard Samuelson, M.P.), delivered the following inaugural address: 

THE WORLD’S PRODUCTION OF PIG IRON.

He showed that the world’s production of pig iron has increased in round numbers from 10,500,000 tons in 1869 to 20,500,000 tons in 1882.  The blast furnaces of 1869 produced on the average a little over 180 tons per week, with a temperature of blast scarcely exceeding 800 deg.  Fahr.  The consumption of coke per ton of iron varied from 25 to 30 cwt.  To-day our blast furnaces produce on the average upward of 300 tons per week.