68 7"ransactions of the American Institute. 



obtained by taking the revolutions of the engine from the register 

 and counting the revolutions of each shaft during the same period of 

 time. This gave the ratio of the speed of the engine to that of the 

 shaft, and by the use of this ratio, the mean speeds of the shafts 

 were obtained from that of the engine.. 



TABLE '^o. 2. 



Summary of the Result ft of the Experiments nnade to ascertain the 

 Economy of the N on- Conducting Steam, Engines at the American 

 Institute ExhiVition of 1S09. 



Babcock and 



Wilcox. Harris. 



«. Duration of experiment, hours ... 8.00 8.00 



h. Diameter of cylinder, inches IG.OO 16.13 



c. Stroke of piston, indies 42 . 00 42 . 00 



d. Eevolutions per minute 60 . 344 60 . 273 



e. Steam pressure in main pipe, p'ds. 81.69 80.51 



f. Point of cut-oflF, in fractions of the 



stroke .189 .226 



g. Mean effective pressure in cylinder 



per indicator, pounds 31 . 057 29 . 728 



Distribution of the Power. 



Ti. Indicated, horse imicer 78 . 792 76 . 579 



i. Friction of enw-ine, per indicated 



diagrams, H.^ 7. 225 4. 601 



j>=A — i. Diiference=gross load, H. P 71.507 71.973 



^=^'X.04. Extra friction of engine caused by 



load, H. P 2.863 2.879 



. 7 Differ- ( ]^et or effective horse pow'r po i-iw oa r^nn 

 m==7 — k. < rv -4.^ 1 xi 1 1 li. 68.704 69.099 



-^ ence ( Iransmitted through belt. 



n. Dynamometer horse power 64.752 67.314 



o=^?n — n. Difference — Friction of connecting 



shaft- 3.952 1 .785 



"Water. 



J). Feed water per hour by meter p'ds 2 > 007 . 746 1 , 995 . 547 



q. Steam per hour by indicator po'ds . 1 , 595 . 496 1 > 815 . 723 



^.__ioo q^ Percentage of water accounted for 



by indicator- 79.47 90.99 



Percentage of moisture present in 



the steam* 20.53 9.01 



