AMERICAN INSTITUTE. 209 



drawer rests; and the opening N, through the back end of tlie 

 bottom of tliat drawer. This opening N is now closed by the 

 division board. When the drawer is closed, these openings M 

 and N coincide, and the air ilows freely through them, as it is 

 fjrced from the lower to the upper drawers by the superior weight 

 of the column of cold air in tlic flue C. The back end of the 

 drawer cuts off all connection with the refrigerator, so that no air 

 can flow out when it is open. The cold air in this drawer being 

 heavier than the air outside, remains in it, unless there are cur- 

 rents in the room, which at most can only sweep the air from this 

 drawer. 



Some of ths gases set free in refrigerators, are absorbed bv ice, 

 or rather by the pure water as it is dissolved from ice. But that 

 alone will not absorb all impurities, nor prevent a refrigerator 

 from accumulating bad odors, as is known practically by all who 

 have used refrigerators for a sufiicient time. 



In order that the air may be rendered perfectly pure, the char- 

 coal filter, S, is placed in the back part of the drawer, so that the 

 air in its rounds is constantly being filtered through the charcoal^ 

 and thus deprived of all its impurities. The water from the 

 melting ice runs into the gutter G, and oft' by a trap pipe not 

 shown. 



These refrigerators are all made double, as represented, and the 

 spaces, which are from one and a half to three inches wide, filled 

 with pulverized charcoal ; this increases the w^eight and cost some- 

 what, but it is essential to practical success. 



This refrigerator is opened at the side, without allowing the 

 cold air to flow out. 



In all oiu- experiments, the air has not only been dried as tho- 

 roughly as it can be by any arrangement with ice, and deprived 

 of some of its impurities by the water at all times flowing over 

 the surfaces of the ice, but it is thoroughly and j^erfectly disin- 

 fected by the filter of charcoal through which it passes at every 

 revolution. In this particular form the charcoal filter, in effect, 

 divides the bureau into two separate refrigerators, and the articles 

 in one can never smell or taste of those in the other. 



[A large silver medal awarded. 

 [Am. Inst.J 14 



