SCIENCE 



THE SHORTT HIGH-SPEED ENGINE. 



The new type of steam-engine illustrated on this and the follow- 

 ing page possesses several points that will naturally attract the at- 

 tention of engineers and steam-users generally. There are features 

 about it that will specially commend it to marine engineers and 

 yacht-owners, as well as to others interested in compact high-speed 

 reversible engines giving a maximum of efficiency with a minimum 

 of fuel, and as free from complication of parts as possible. 



results as to strength and stiffness are got from a given weight of 

 metal. The pistons are double-acting ; thai is, slgam is admitted 

 to them at each end of the stroke. An engine of this type, with 

 cylinders two inches in diameter and two-inch stroke, will develop 

 two horse-power under ordinary conditions, but with high steam- 

 pressure it is capable of doing much more. A launch engine of 

 this size and power, running at four hundred revolutions a ininute, 

 has been used to run a twenty-five foot launch during the past year 

 with e.tceUent results. Though the model of the boat is not one 



FIGS. I AND 2. — THE SHORTT DUPLEX HIGH-SPEED ENGINE. 



The engine shown in the illustrations is known as the Shortt 

 duple.x high-speed engine, and it is being placed on the market by 

 the Hussey Re-heater and Steam Plant Improvement Company of 

 this city. Figs, i and 2 are perspective views of a reversing engine 

 designed more especially for steam-launch and yacht service. Fig. 

 3 is a section showing the frame, cylinder and piston, steam-valve, 

 connecting-rod, etc. It will be observed that there are two cylin- 

 ders and a double crank, the crank-pins being set at an angle of 

 ninety degrees with each other, thus preventing the engine from 

 ever being on a dead-centre. The cylinders are made in one cast- 

 ing, and are supported on a frame of .-\-paitern, in which the best 



calculated for speed, it is said to have run along easily and con- 

 tinuously at a rate of ten miles an hour. 



The valves, though cylindrical in form, are the same as the regu- 

 lar slide-valve in action and principle. They take their motion 

 from the pistons, the piston and valve of the right-hand cylinder 

 controlling the admission and cut-off of steam to the left-hand 

 cylinder, and vice 'ivrsii, the steam ports being crossed. Fig. 4 is 

 a diagram of the valve-seat and ports, the dotted lines showing the 

 crossed steam-passages. The steam-ports are designated by the 

 letter D. and the e.xhaust ports by C. The valves are shown in 

 Fig. 5, £■ being the reversing- valve, and /^ the main valves. The 



