ANNUAL OF SCIENTIFIC DISCOVEKY. 



end of the cylinder, and thus drives the piston toward the other end, tighten- 

 ing all the brakes by its connection with the usual compound levers. Turn- 

 buckles are provided, by which the rods may be taken up to compensate for 

 wear. The brakes are of the usual proportions, shod with iron ; the cylinder 

 is six inches in diameter ; the stroke or motion allowed the piston is ten 

 inches, and the diameter of the pipe one and a half inches. The pipe connects 

 with the upper portion of the boiler, and a lever is provided by which the 

 engineer allows steam to flow for a longer or shorter time, then closes the 

 valve and allows the steam to act by expansion. By turning the lever in 

 another position, the steam in the cylinder and pipe is discharged into the 

 atmosphere, and the brakes immediately released, so that the friction may be 

 taken off and let on again, with any required degree of strength, several 

 times in a minuto if desired. Wheels should never be entirely stopped while 

 the train is in motion, as the slipping on the rail is very injurious; and by 

 properly proportioning the parts, a very close approach to this resistance may 

 be obtained without ever exceeding it. 



A small self-acting valve, opening inward, is provided in the lowest part of 

 the pipe, under each car. This valve is operated by a spiral spring, and opens 

 the moment the steam is discharged. It allows all the water to dribble out 

 at leisure, and keeps the whole always ready to act in the coldest as well as 

 in the warmest weather. The invention has been tested on the Michigan 

 Central and other lines in the "West, and has been recently introduced on the 

 New York and New Haven road. In case of sudden danger it allows the 

 engineer to put on the brakes in a second of time, and again to release them 

 as quicklj r , if he discovers Ms fears to have been unfounded. The steam con- 

 sumed is usually taken when it can best be spared as the engine approaches 

 a station, and is found too small in amount to be of any importance. The 

 strain being necessarily equal on every brake, the banging of cars together is 

 entirely avoided, and the elasticity of the steam renders the action of the 

 brakes in every respect smooth and uniform. 



A rail-road brake, embracing some novel points, has recently been intro- 

 duced upon the Orleans (France) road. The objection to the ordinary hand- 

 brake is. that it requires half a dozen turns before taking effect, and that its 

 efficiency depends upon the watchfulness, vigor, and constant attendance of 

 the brakeman. There is no certainty that the six or eight brakemen upon a 

 train invariably, immediately, and simultaneously bring their forces to bear. 

 The new instrument is such that the greater the speed and weight of the train, 

 the greater its effect. Each car is fitted with one, which has no need of any 

 one to manage it. Upon the tender is an ordinary brake of the old construc- 

 tion, which is put down by the stoker as the engineer turns off the steam. 

 The result is to bring all the cars down upon the engine, with the whole 

 weight of the momentum acquired. They press upon each other, and this 

 pressure the tender resisting powerfully, as its wheels are no longer turning, 

 but sliding is sufficient to put the instrument into play, and the wheels of 

 the whole train are almost immediately blocked. The stoppage of movement 

 is prompt, without being sudden, and the entire control of the train is cen- 

 tered where it ought to be, upon the engine. 



