64 TRAXSACTIOyS OF TUE AMERICAN INSTITUTE. 



A copy of the regulations for the trial (exhibit E) was also posted 

 in the engine room. 



During some preliminary trials, the load was found insufficient at 

 certain hours of the day,- and varied too greatly for a satisfactory 

 trial. To remedy this, a pressure blower, on exhibition, of the Eoot 

 patent, producing a positive blast by piston displacement, was fitted 

 with wider belts, and the discharge orifice closed, so as to cause an 

 additional resistance of eleven horse power. A five-foot Dimphel 

 blower was also obtained (of the Novelty Iron Works), and after 

 some delay, erected and put in motion at 900 revolutions per minute. 

 This gave most satisfactory results. Working at full capacity, it 

 furnished a resistance of about twenty-five horse power, and this 

 could be reduced at will by simply closing the discharge orific. 



During the trial all the machinery that the exhibitors would leave 

 in our charge, was kept in motion steadily. Some of the exhibitors 

 were so accommodating as to remain late at night to keep their 

 machines in operation. With all the machinery and the blowers in 

 motion, the indicator diagrams showed over one hundred horse-power. 

 Of this, it Avas /found that eighty horse power could be kept up 

 steadily with the outlet of the large fan, partially closed, so that it 

 could be opened to regulate the load when any macliinery of impor- 

 tance was thrown off. Before commencing the experiments it was 

 ascertained that the boilers and all their steam and water connections 

 were perfectly tight, and the whole steam pipe was thoroughly felted. 

 During the test of each engine all outlets in the steam pipe leading 

 to other engines or pipes were shut oft", not only by the valves but bj 

 putting blank flanges in the unions provided for the purpose. All 

 surplus steam and water connections were cut off from the boiler, and 

 the steam feed pump was, during the experiments, supplied with 

 steam from the boiler of the Baxter portable engine. By these pre- 

 cautions it is certain that all the steam that passed through the engine 

 was measured as water by the meter before entering the boiler. The 

 tension of the dynamometer springs was carefully adjusted before 

 starting, and to avoid all questions in regard to friction, the belts 

 were removed from all of the engines except the one undergoing trial. 



A log, or record, was kept of the experiments on which was 

 recorded, every fifteen minutes, the pressure of steam and readings 

 of the dynamometers. The revolutions of the engine were counted 

 by an engine register, the reading of which was taken every half 

 hour. The temperature and quantity of water used were recorded 



