APPENDIX. l8/ 



to these records of the coal and the feed-water, half-hourly 

 observations should be made of the temperature of the feed- 

 water, of the flue gases, of the external air in the boiler-room, 

 of the temperature of the furnace when a furnace-pyrometer 

 is used, also of the pressure of steam, and of the readings of 

 the instruments for determining the moisture in the steam. 

 A log should be kept on properly prepared blanks containing 

 columns for record of the various observations. 



When the " standard method" of starting and stopping 

 the test is used, the hourly rate of combustion and of evapo- 

 ration and the horse -power may be computed from the 

 records taken during the time when the fires are in active 

 condition. This time is somewhat less than the actual time 

 which elapses between the beginning and end of the run. 

 This method of computation is necessary, owing to the loss 

 of time due to kindling the fire at the beginning and burning 

 it out at the end. 



XIII. Quality of Steam. The percentage of moisture in 

 the steam should be determined by the use of either a throt- 

 tling or a separating steam-calorimeter. The sampling-nozzle 

 should be placed in the vertical steam-pipe rising from the 

 boiler. It should be made of -J-inch pipe, and should extend 

 across the diameter of the steam-pipe to within half an inch 

 of the opposite side, being closed at the end and perforated 

 with not less than twenty ^--inch holes equally distributed 

 along and around its cylindrical surface, but none of these 

 holes should be nearer than j- inch to the inner side of the 

 steam - pipe. The calorimeter and the pipe leading to it 

 should be well covered with felting. Whenever the indica- 

 tions of the throttling or separating calorimeter show that the 

 percentage of moisture is irregular, or occasionally in excess 

 of three per cent, the results should be checked by a steam- 

 separator placed in the steam-pipe as close to the boiler as 

 convenient, with a calorimeter in the steam-pipe just beyond 

 the outlet from the separator. The drip from the separator 



