THE POWER INIA POUND OF COAL.

Evening Star, Issue 11267, 14 June 1900, Page 5

THE POWER INIA POUND OF COAL.

A pound of what we will call average coal would be somewhat smaller in size than a man's fist. A pound of this coal, if expended in mechanical work, would give us 236-horse power (says a writer in ' (JiWirr's Magazine' for May). Imagine at iho thin; of the Pharaohs two long lines of men, extending over half a mile, all pulling stcadilv, at the command of a taskmaster, at a givi'i rope to raise some huge obelisk, and as veil see them sweating, tugging, and straiiiirg think again of this small lump of coal, in which Nature has placed an equal amount of power. <ln some countries men who have been specially trained as porters to carry heavy loads on their backs will, as a full day's work, carry a total of from 350 to 600 pounds a distance of one mile. And yet each has expended but one-third of the power stored up in this pound of coal. An exceptionally strong man has been known to do one-half horse-power of work as his mightiest effort; but in two and a-half minutes work at this rate exhausts his muscular force. Let us suppose 100 such men putting forth such extreme effort at rope, or crank, or crowbar. As thev fall back, red-faced and puffing, to catch their breaths, we might imagine this little black lump saying to them: " I can do as much as your whole company, and then can stand it for fully two minutes longer before I am exhausted." In sawing wood a man may work at the rate of about sixty strokes a minute and consider himself a " top-sawyer," and his saw blade may have progressed five feet a minute; but a circular saw driven by machinery may be put through seventy times that distance and saw seventy times as much wood. And yet this one little pound of coal'contains power enough for 180 such saws.