NOTE BY W. FAIRBAIRN, F.R.S. F.G.S. 485 
Nominal Power of living 
Engines. Horse-power. Horses required to do 
the same work. 
283 for pumping and blowing 11,247 & 4 44,988 
805 rotative swe) RSIS HS 87,854 
76 boat engines J" 2086588 6,240 
1,164 | 25,945 89,082 
a 
“ And between January 1824 and January 1854, the num- 
bers are the following :— 
, 84 for pumping and blowing 2,403 4 9,612 
164 rotative ° . . 17,5173 22,551 
243 boatengines . . 15,358X3 46,074 
44] 25,278 78,237 
“ Giving the following total numbers :— 
ARO Hie He dees. 26,045 89,082 
Roar. <--» SB278 78,237 
1,605 51,223 167,319 
“The first engine seems to have been made for Bedworth, 
in 1776.” 
It will be noticed that for pumping engines the nominal 
horse-power is multiplied by four to give the real horse-power 
required to do the same work in the same time; and this is 
on the supposition that a horse can work only six hours a day, 
whilst the engine can work twenty-four. But in rotative en- 
gines an allowance has been made in the above table for loss 
of power in the action of the crank, &c. as compared with the 
direct action in the other case, and the nominal horse-power 
is multiplied by three only. 
Perhaps it would be more accurate to suppose that a horse 
can work for eight hours out of the twenty-four ; but at the same 
time to multiply the nominal horse-power by two, because 
