MECHANICS AND USEFUL ARTS. 58 



The steam passes into each pipe, and the cold water is applied both 

 upon the outside, and also upon the inside surfaces ; there is therefore 

 a double cooling surface for the steam in each pipe. This arrange- 

 ment is said to work excellently in practice, and to save a large 

 amount of fuel. 



HYDEAULIC REGULATOR FOR STEAM-ENGINES. 



THIS regulator, invented by Messrs. Thurston and Green of New 

 York, is a cast iron cylinder, about 18 inches high, and 6 in diameter. 

 This cylinder contains two brass cylinders, with plungers and piston 

 rods attached, one being 3 inches in diameter, and 4 inches high, and 

 the other is 2 inches in diameter, and 12 inches high. Connected 

 with the two inch cylinder at the bottom is an escape faucet, by which 

 the fluid which is forced into that cylinder may escape when open. 

 The piston rod connected with the plunger of the two inch cylinder 

 or pump, is connected at the top with a lever attached to the stem of 

 the steam valve of the engine, and the piston of the three-inch cylin- 

 der is connected with the engine in such a manner as to drive the 

 pump's plunger 100 motions per minute. This pump forces the fluid 

 from the outer cvlinder into the two-inch cylinder at the bottom, and 



V V 



the faucet is opened just far enough to allow the fluid forced into the 

 two-inch cylinder to escape without the plunger of the cylinder being 

 raised more than four inches, being the amount of play or vacillation 

 allowed this rod and plunger when the engine makes the number of 

 revolutions per minute required. Attached to the upper part of this 

 piston rod is a weight capable of opening the valve at all times when 

 there is not fluid enough forced in to hold the plunger up high enough 

 to close the valve. By this means engines can be held, regardless of 

 the kind of work to be performed, so as not to vary more than half of 

 one revolution per minute ; for when the engine increases in speed, 

 by machinery being thrown out of gear, or on account of a higher 

 pressure of steam, the pump is driven faster, more fluid is thrown into 

 the two-inch cylinder than provided for, the plunger in the cylinder 

 is thrown higher up, and the top of the piston rod of the plunger 

 being connected with the steam valve, the valve is partially or entirely 

 closed, so that no more steam can pass the valve than just enough to 

 give the desired number of revolutions. If the engine does not run 

 so as to drive the pumps at one hundred revolutions, there is not fluid 

 enough forced into the two-inch cylinder to keep the plunger up ; 

 consequently it drops down and opens the valve, until the exact vol- 

 ume of steam to drive the engine the desired number of revolutions 

 is received. JV. Y. Farmer fr Mechanic. 



IMPROVED GOVERNOR FOR STEAM ENGINES. 



JOHN TREMPER, of Buffalo, X. Y., has invented a very simple 

 and beautiful improvement on Governors for steam engines. It can 

 be made at a very small cost in comparison with the common governor. 



