94 



BOILER TESTS. 

 Results of Tests, Boiler No. 10. 



Tests No. 19 and No. 20, made on Boiler No. 10, had for 

 an object the determination of the economy of automatic regu- 

 lation of the draught over hand regulation. On the test with 

 hand regulation the method pursued was to alternately open 

 and shut the damper through its full range during the whole 

 progress of the test. When the damper was open it was kept 

 in this position till the steam pressure rose to a certain figure 

 determined upon beforehand. It was then closed and kept in 

 that position till the pressure fell to a certain lower figure. 

 Test No. 19 gives the average of three trials, on the first of 

 which the variation in pressure, in the manner noted, amounted 

 to 4 pounds, on the second, 7 pounds and on the third 1 

 pound. On the test with automatic regulation the type of 



