Note 391 — ARTIFICIAL ICE. COOLING LIQUORS.

.. a number of small, shallow, earthen pans. These are unglazed, scarce a quarter of an inch thick, about an inch and a quarter in depth, and made of an earth so porous, that it was visible from the exterior part of the pans, the water had penetrated the whole substance. [Our ordinary wine-coolers, which consist of extremely porous vessels, act from evaporation. A portion of the water, which is placed in the interior of the cooler, evaporates through its pores, and produces cold by rendering a considerable amount of heat latent.]