On a warm autumn day in 1797, an expatriate Englishman, raised in America, was sweating. It was not the weather making Count Rumford so hot but the progress of an experiment he was conducting at the Bavarian arsenal. On his orders, two horses were turning a drill connected by gears to a newly cast metal cylinder. Rumford, it would have seemed to a casual onlooker, was simply supervising the production of cannon for use against the armies of revolutionary France. The onlooker would have been wrong, for Rumford's method differed from the standard process of cannon boring. Rumford had deliberately left the drill-bit blunt and encased the barrel in a tank of water. His apparatus was dedicated not to rearmament but to enlightenment--he was aiming not at France's soldiers but its scientists. (1)
For several years, Rumford had been devising experiments to test the nature of heat, a subject of considerable dispute among scientists. According to Lavoisier, the eminent French chemist, heat was a subtle fluid (caloric) squeezed out of a body when mechanically acted upon. Compressing a gas pushed caloric out of it, giving off heat. Hammering an iron bar knocked caloric out of it by percussion; rubbing metals together produced heat by squeezing caloric from their surfaces. Lavoisier supposed heat to be a material substance that drained out of one body into another. Rumford was convinced that Lavoisier's "supposition is quite unnecessary," and he set his horses to work to prove it (qtd. Brown 195). The gun barrel and the blunt drill would produce intense heat by friction. He would measure it by recording how long it took to boil the water in which the barrel was immersed. If heat really was a fluid, then over time the quantity present inside the barrel would begin to run out.
Rumford put his horses and his thermometer into action and found that, however long they labored at the mill, the time taken to boil the water was the same. Far from running out, the heat produced by the rubbing of drill and barrel "appeared evidently to be inexhaustible." Heat, he concluded, "cannot possibly be a material substance" (qtd. Brown 198). Lavoisier was wrong; heat was no caloric fluid but a form of "MOTION." On 25th January 1798 Rumford's findings were read to Britain's Royal Society and then published. Soon his work had been reported in Germany, Switzerland and France and Rumford had become the champion of anti-caloric scientists all over Europe. By the 1840s, it was accepted that heat was a form of energy or work, and Rumford was hailed as the great scientist who first demonstrated the equivalence of heat to work.
While in Rumford's experiment two horses did the work to make the heat, on the other side of Europe, single boys as young as five labored to make others warm. As apprentice chimney sweeps--"climbing boys"--many were worse off than Rumford's ponies, for, as Leigh Hunt noted, they were Britain's own "little black boys"--as much slaves as were the children on the West Indian sugar plantations:
The progress of the poor child in sweeping the chimney closely engrossed her [a West Indian servant's] attention, and when she saw him return from his sooty incarceration, she addressed him with a feeling that did honour to her material tenderness, saying, 'child! come yaw, child,' (and without waiting any reply, and putting a sixpence into his hand;) 'Who you mammy? You hab daddy, too? Wha dem be, da la you go no chimney for?' and moistening her finger at her lips, began to rub the poor child's cheek, to ascertain, what yet appeared doubtful to her, whether he was really a buccara, (white.) I saw this woman some time after in the West Indies; and it was a congratulation to her everafter, that her 'children were not born to be sweeps.'
(Hone I, 591)
The rich and famous scientist and Britain's "black" slaves seem worlds apart. Rumford spanned Europe; climbing boys were a specifically English phenomenon. …