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Various

"Scientific American Supplement, No. 430, March 29, 1884"

to 100 deg. and 537 in converting the water at 100 deg. into steam at 100 deg..
This second quantity is called the _latent heat_ of the steam at 100 deg..
The sum of the two quantities is called the _total heat_ of the steam at
100 deg.. The total heat of the steam remains nearly constant, whatever be
the temperature at which the vaporization occurred.
[Illustration: THE WEIBEL-PICCARD EVAPORATION APPARATUS.]
In order to utilize the steam as a means of heating, it is necessary to
condense it, that is to say, to cause it to pass from the gaseous to a
liquid state. This conversion disengages as much heat as the passage
from the liquid to the gaseous state had absorbed.
It results from this that if we could condense the steam that is given
off by a liquid that we are vaporizing, in contact with another liquid
that it is also a question of vaporizing, we should utilize all the heat
contained in the steam that was being given off from the first.
This object can be practically attained by two means, viz.


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