Crystal Palace International Electric Exhibition 1881-82

(devised by Professors Ayrton and Perry) for measuring the power transmitted to electric generators or other machinery driven, by belting, &c.; Dynamometer Couplings for showing the power transmitted to electric generators or other machines when working direct from the shaft of the engine, or for measuring the power transmitted "by lines of shafting, &c. ; Dynamometer Pullies for use upon the machine shaft. North Nave. 365.—Thomson, Sterne, & Co., Limited (Managing Directors, L. Sterne and J. B. Handyside), the Crown Iron Works, Glasgow ; 10, Victoria Chambers, Westminster, London; and 10, Rue Laffitte, Paris. Clerk's Patent Gas Engine. The engine possesses the distinctive feature of making an explosion at every revolution. The engine comprises two cylinders, one the working and the other the so-called “ displacer” cylinder. The diameter of the former is 6 in., and the stroke is 12 in.; the piston is connected to the crank in the ordinary manner, but the piston of the dis- placer cylinder, in which the pressure is very slight, never exceed- ing 41b. to the squai’e inch, is driven off a pin in one of the arms of a fly-wheel. The pin is at right angles to the crank, and in advance of it. When the piston in the displacer advances, a combustible mixture of gas and air is drawn in during the first half of the stroke, the admission valve is then closed, and air is admitted during the remainder of the stroke. On the return of the piston a valve is opened automatically, making a communication between the two cylinders. At this time the piston of the motor cylinder is at the outer end of its stroke, and an annular port opens, communicating with the exhaust. Through, this opening the products of combustion from the last explosion pass, the pressure in the cylinder falls, and the cylinder is ready to receive its next charge from the displacer chamber. The first portion that enters the cylinder from the displacer is the pure air that passed in after its piston had reached the half-stroke, and the combustible mixture of gas and air had been cut off. This flows through the motor cylindei’, scouring it out at each, stroke, and escaping through the exhaust ports until the latter is closed by the piston on the return stroke. Meanwhile the explosive mixture has followed the pure air into the motor cylinder, and remains there, as the exhaust ports have now been closed. The piston, on its return stroke, compresses this mixture in a space at the end of the cylinder to about 451b. pressure, when the chai’ge is ignited, the pressure rising to some 2501b. per square inch, and driving forward the piston of the motor cylinder, when the exhaust ports are again opened, and the exploded gases escape, leaving the cylinder free for the next charge from the displacer. This series of operations takes place at every stroke. This engine can be worked up to its full available power without irregularity, and for electric lighting is specially adapted, and all other power where a steady power is absolutely necessary. West Corridor. 366.—Turner Gas Engine Company, St. Alban’s Iron Works. 1 horse-power Patent Gas Engine, £65 ; % horse-power Patent