472 THE POPULAR SCIENCE MONTHLY. 



have now to be described and illustrated. We will deal with them in 

 chapters on " the Educational Bias," " the Bias of Patriotism," " the 

 Class-Bias," " the Political Bias," and " the Theological Bias." 



-- 



THE WAKMING OF HOUSES. 



By JOHN P. SEDDON, Esq. 



THE usual appliances for w T arming houses, setting aside comprehen- 

 sive systems, resolve themselves into open grates, close stoves, 

 and, under special conditions, gas apparatus, and pipes for hot air or 

 water for warming halls and passages. 



For the whole of these certain general rules may be laid down : 



1. More cannot be got out of any one of them than is put into it. 

 This is an axiom which, truism as it appears, is necessary should be 

 impressed upon the public mind, which is apt to assume that engineer- 

 ing skill can multiply the heating power of fuel indefinitely. Thus, 

 materials like fire-clay, which are absorbent of heat and useful to pre- 

 vent its escape, and retain it till needed, must abstract it first from 

 the fuel before it can dispense it. 



2. There are but 100 degrees of percentage. This simple fact 

 should be kept in mind in considering methods of saving fuel, the in- 

 ventors of which would otherwise persuade one that reference to coal- 

 merchants is a work almost of supererogation. 



3. Some proportion of the heat generated must be expended in 

 maintaining a draught in the flue, which is to carry off the products 

 of combustion. This is by no means unprofitably lost, since it pro- 

 motes ventilation as well. 



4. To minimize this proportion of escaping heat to as nearly as 

 possible what is just necessary, and to take toll from it during its pas- 

 sage, as by warming the air which is to replace that abstracted by the 

 flue, are the principal directions which efforts to economize fuel should 

 take. 



5. The products of combustion, being noxious, must be wholly re- 

 moved, unless they can be chemically transformed. It is as barbarous 

 to allow the fumes from gas to invade rooms, as it is to let the door be 

 the sole outlet for peat-smoke in an Irish cabin, or as it was to provide 

 only louvers in the roofs of the halls of our forefathers for the smoke 

 of their wood-fires. The evil may be disguised, but the poison is the 

 more insidious from being comparatively unfelt. The lungs of the 

 living animals, as the leather of dead ones on the book-shelves, become 

 corroded alike -by its pernicious influence. 



G. Warming and ventilation are so intimately connected that, al- 

 though the latter is not my special subject upon this occasion, it is 



