208 



ENGINE TESTS. 



a pound, or about 2 %. The nature of the action which the 

 jackets produced is shown in the analysis of the diagrams. 

 With the jackets on, the steam accounted for in the low-pres- 

 sure cylinder is the greatest ; whereas, with the jackets off, the 

 steam accounted for in that cylinder is the least. 



Another noticeable thing in the action of the jackets is in 

 the distribution of the power between the cylinders. With 

 jackets on, the low-pressure cylinders developed 92 horse- 

 power more than the high-pressure cylinders, or about 30 % ; 

 whereas, with jackets off, the increase was only 24 horse-power, 

 or about 7 / . 



NOTE. The quantity of steam condensed in the jackets on the first three 

 trials was respectively, 11.4 %, 10.8 %, and 10.8 % of the total quantity con- 

 sumed ; and these are included in the figures given in the tables. 



