VARIOUS APPLICATIONS OF STEAM. 535 
sider, that a large proportion of this power is ap- 
phed to move machinery, and that the amount of 
work now done by machinery in England, has 
been supposed to be equivalent to that of between 
three and four hundred millions of men by direct 
labour, we are almost astounded at the influence 
of Coal and Iron and Steam, upon the fate and 
fortunes of the human race. " It is on the ri- 
vers," (says Mr. Webster,) *' and the boatman 
may repose on his oars ; it is in high ways, and 
begins to exert itself along the courses of land 
convevances ; it is at the bottom of mines, a 
thousand (he might have said, 1800) feet below 
the earth's surface ; it is in the mill, and in the 
workshops of the trades. It rows, it pumps, it 
excavates, it carries, it draws, it lifts, it hammers, 
it spins, it weaves, it prints."'* 
We need no further evidence to shew that the 
presence of coa,l is, in an especial degree, the 
which would do the work of that number of horses constantly 
actuig, but supposing that the same horses could work only 8 
hours in every 24, there must be 75 horses kept at least to produce 
the effect of such an engine. 
The largest Engine in Cornwall may, if worked to the full ex- 
tent, be equal to from a 300 to 350 horse power, and would there- 
fore require 1000 horses to be kept to produce the same constant 
effect. In this way it has been said that an Engine was of 1000 
horse power, but this is not according to the usual computation. 
Letter from J. Taylor, Esq. to Dr. Buckland. 
* As there is no reproduction of Coal in this country, since no 
natural causes are now in operation to form other beds of it; 
whilst, ownig to the regular increase of our population, and the 
