The Egyptians, thousands of years ago, appreciated as much as we do now, cool water in summer, and they had many devices for cooling it by evaporation. The common jug of red clay, used to this day all over the East as a water bottle, is porous and unglazed, and by the evaporation of the thin'film of water which is constantly permeating throngh the pores to the surface, the contained liquid is kept comparatively cool. The principle on which the well-known and generally-used ice pitcher acts is very different. When we place a piece of ice in water, the heat, latent and sensible, is called forth to melt the ice, and in so doing the water is constantly kept at the same temperature as the ice, just iO long as any ice remains. Now if we surround the pitaher in which the ice and water is placed with a non-conductor, so as to prevent radiation of, cold, or more properly, the entrance of heat, the ice will be retained much longer, and the water will remain cooler, for a greater length of time. To do this, the double-walled vessel called an ice pitcher, and e-tion of which fofms our first illustration, was devised by James Stimpson, and patented October 17,1854. His claim is on the double wall pitcher, with double. sides, bottom, and ? lid, the lid having a chain or string attached to the handle. Well as this has answered for a long period, it was yet capable of some improvement, in order that the ice might be made to last still longer, and the water kept cool for a greater length of time. This desirable improvement has now been made by George W. Smith, of Hartford, Conn., who has added another wall to the pitcher, and made it a treble instead of a double-walled one, thus doubling its cooling powers without much extra labor or expense. Our second illustration is a section of one of these, E G being the outside case, inside this is another, A', and with the inside case, A B, form the three walls. These cases are perfectly independent of each other, and are only connected or joined together at the top, ! F, on which the lid, C, rests, which is also C treble-walled. To the lid there is a hinged S? lip, I, that opens by its gravity as the pitcher is inclined, and allows the water to flow through the spout, D, thus rendering it unnecessary to open the lid except when the pitcher is to be replenished with ice or water. That this is an improvement every one will see, and we have no doubt that they will be generally introduced. Specimens of these pitchers can be seen at the office of the manufacturers, Messrs. Rogers, Smith Co., 170 Broadway, New York, or Hartford, Conn.
This article was originally published with the title "Science and Art"