238 ENGINE TESTS. 



Engine No. 59 is a horizontal four-cylinder engine, arranged 

 in the manner of a pair of tandem compound engines. The 

 cylinders nearest the beds are the low-pressure cylinders, of 

 which there are two. The high-pressure cylinder is in front 

 of one of the low-pressure cylinders, and the intermediate 

 cylinder in front of the other. The cylinders are jacketed on 

 the system which allows the steam which is supplied to the 

 cylinder to first pass through the jacket space, each jacket thus 

 being filled with steam having the initial pressure of supply. 

 The jackets are drained into receivers, and these are provided 

 with pumps operated by the engine. They discharge the 

 water into reheaters placed in the flue of the boilers. The 

 steam which is formed in the reheaters is supplied to the re- 

 ceiver between the intermediate and the low-pressure cylinders. 

 This receiver is provided with a coil of live steam pipe pre- 

 senting 33 square feet of exterior surface. The total quantity 

 of water condensed in the jackets and withdrawn from them 

 amounted to 691 Ibs. per hour, or about "> </, of the total quan- 

 tity of steam supplied to the engine. About one-half of this 

 was re-evaporated in the reheater and utili/ed in the low- 

 pressure cylinders. Tin- condensers, of which there are t\\... 

 are of the jet type, and operated by direct connected air-pumps. 

 Steam is supplied from vertical tubular boilers, and <>n the test 

 it was superheated 39 at a point near the boilers. With the 

 exception of the high-pressure piston, which leaked quite badly, 

 the valves and pistons were all in a practically ti^ht condition. 



The load on the engine consisted of cotton machinery. The 

 loss of steam which, referring to the analysis of the diagrams, 

 took place between the intermediate cylinder and the low-pres- 

 sure cylinders is noticeable in view of the arrangements made 

 to reheat the steam in the receiver, and augment the supply 

 by means of the jacket-water re-evaporated in the flue heaters. 

 It shows the powerful action of cylinder condensation, and the 

 necessity of employing more efficient means for overcoming 

 the loss. 



