Bache.] 



324 



[Nov. 17, 



Tlie source of supply may be through a coaduit from the open air, or 

 through one leading from a properly cemented and sanitarily kept cellar, 

 the terminal of the conduit in either place being covered with metallic 

 gauze to exclude dust. Tlie air of a dwelling-house cellar should be as 

 pure as that of the rest of the house. Hence it is a mistake in a furnace- 

 heated house to draw for the air-chamber of the furnace, directly from 

 outdoors, most of its supply. In a cellar properly regulated in every par- 

 ticular, the air from the furnace should be drawn from outdoors, mostly, 

 if not entirely, through the intermediation of the cellar, thus searching and 

 keeping sanitarily sweet its inmost recesses. 



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Rapidity of movement of the air for the oven, dependent upon differ- 

 ences of density, being secured by constituting either outdoors or the 

 cellar the source of supply, ample amount of it is thereby necessarily in- 

 volved. The ability to secure purity for this air being naturally asso- 

 ciated with the means adopted to obtain ample movement, involving 

 amount, it remains only to remark that contirtuity of the movement of the 

 air is necessarily a concomitant of the other conditions, and to consider 

 lastly the points of its regulation and distribution. The first of these ends 

 is secured b}' the construction of llie apparatus described, and the second 

 by the employment of the single damper, as represented in the diagrams 

 exhibited. 



Whether the air, after having passed through the oven, shall be dis- 



