26 MR. JOHN GRAHAM ON CONSUMPTION 
considered as 6.09 Ibs. of water evaporated by one pound 
of coal. 
Or by adding one-sixth to that quantity for the heating 
of the feed water from 60° to 212°, the evaporating power 
will be 7.1 lbs of water evaporated by one pound of coal. 
I have already stated that as these experiments pro- 
ceeded, the deviations from uniformity became less per- 
plexing, and when such deviations occurred they were 
more readily accounted for. The following short table is 
given to illustrate the degree of accordance of such ob- 
servations. 
Table D. 
Water evaporated from 60° per pound of coal burned. 
By Thick Fires. By Thin Fires. 
Lbs. Observations, Lbs. Observations. 
5.70 Monday. 5.63 
6.20 5.65 
5.97 5.74 
6.04 5.57 Saturday. 
5.79 5.85 Monday. 
5.90 5.57 
5.51 Monday. 5.36 Dirty coals. 
5.93 5.64 
5.20 New fireman. 
6.00 Old fireman. 
&e. &e. 
IX. Series or EXPERIMENTS. 
Fig. 12. 
Scale of feet 
20123. 5 20 25 let 
The next boiler experimented with was also plain and 
cylindrical, 42 feet long and 6 feet in diameter. 
