Latent Heat
In 1761 Black deduced that the application of heat to ice at its melting point does not cause a rise in temperature of the ice/water mixture, but rather an increase in the amount of water in the mixture. Additionally, Black observed that the application of heat to boiling water does not result in a rise in temperature of a water/steam mixture, but rather an increase in the amount of steam. From these observations, he concluded that the heat applied must have combined with the ice particles and boiling water and become latent. The theory of latent heat marks the beginning of thermodynamics. Black's theory of latent heat was one of his more-important scientific contributions, and one on which his scientific fame chiefly rests. He also showed that different substances have different specific heats.
This all proved important not only in the development of abstract science but in the development of the steam engine. The latent heat of water is large compared with many other liquids, so giving impetus to James Watt's successful attempts to improve the efficiency of the steam engine invented by Thomas Newcomen. Watt added a separate condenser, and kept the cylinder at the temperature of steam (by enclosing it in a steam-filled jacket) so saving a considerable amount of energy in avoiding the reheating of the cylinder at every cycle of the engine.
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Famous quotes containing the words latent and/or heat:
“Perhaps having built a barricade when you’re sixteen provides you with a sort of safety rail. If you’ve once taken part in building one, even inadvertently, doesn’t its usually latent image reappear like a warning signal whenever you’re tempted to join the police, or support any manifestation of Law and Order?”
—Jean Genet (1910–1986)
“The train was crammed, the heat stifling. We feel out of sorts, but do not quite know if we are hungry or drowsy. But when we have fed and slept, life will regain its looks, and the American instruments will make music in the merry cafe described by our friend Lange. And then, sometime later, we die.”
—Vladimir Nabokov (1899–1977)