Report of Superintendent. 67 



The experiments with the Babcock & Wilcox engine commenced 

 at three p. m., but on account of- a small misunderstanding in regard 

 to the supply of steam for the feed pump, it was thought best to 

 commence again at four p. m., after which the trial proceeded unin- 

 terruptedly for eight hours, until midnight. The trial of the Har- 

 ris engine was commenced also at four p. m., and continued the 

 same time. During this trial some of the instruments used gave 

 trouble ; for instance, the counter stopped working and had to be 

 twice replaced, making it necessary to get the average revolutions 

 from the time in which the registering took place. The hand indi- 

 cating the power passing through the north dynamometer also 

 dropped off and it became necessary to stop the engine in order to 

 replace it. This was done without any loss of steam. The loss of 

 time was estimated from the loss in revolutions shown by the coun- 

 ter. By this means the revolutions caused by the momentum of the 

 parts in stopping balanced the extra steam required to put the 

 machinery again in motion. 



The details in table No. 1 are given more particularly than the 

 judges may require, to enable the exhibitors who may see this report, 

 to compare their own memoranda with the official record. For 

 instance, in taking the readings of the meter, it was necessary that 

 the water should be at the same height in the boiler in all cases. 

 To accomplish this, strings were tied around the glasses of the water 

 gauges, three and one-half inches above the bottom. The water was 

 brought to this level as nearly as possible, at the end of every hour,, 

 the feed pump stopped, and the time noted in seconds. The read- 

 ing of the meter was then taken and the pump again started. It 

 was thus ascertained that the difference between the time of taking 

 the meter at starting and stopping the experiments was, for Babcock 

 & Wilcox, 7.98 hours, and for Harris 8.029 hours ; but as the latter 

 engine stopped .045 of an hour, the water was actually used in 7.98 

 hours. From this, the water used in eight hours was easily calcu- 

 lated. The dynamometers were designated, according to position, 

 as north, middle and south. The mean reading of the dynamome- 

 ters are given, to which are added, in some instances, the small 

 correction required to bring their indices to zero after stopping. 

 The readings of the middle and south dynamometers show the power 

 due to a speed of 100 revolutions per minute, and the north instru- 

 ment the power due to 200 revolutions. These readings must there- 

 fore be corrected by the actual speeds of the shafts which were 



