184 S. Webber on Ventilation. 
chimney as narrow as possible consistently with a fair and free 
escape of the sinoke ; and it might be provided with a slide under 
the mantle bar, for the purpose of rendering the opening wider or 
harrower, as the state of the fire and the chimney may require. 
nother point to be carefully attended to is the character of 
the air brought in by the supply pipe to be warmed and 
into the room. This should be brought from the outside of the 
house, in some place where it may be presumed to have at least 
a fair average degree of purity, where the currents of the atmos- 
phere have a free circulation, and, if possible, where sunshine 
penetrates during some portion of the day. To bring it from 
under the house merely, or from a cellar, from the neighborhood 
of a drain, or from a damp close, where wind and sunshine seldom 
obtaining a given degree of warmth in the house, and also as 1 : 
the amount of labor necessary, there may be much anne . 
omy in the plan. But that the arrangements generally made é sie 
