HOUSE-VENTILATION. 605 



tical for theorists, and in its results too jjliilosophical for " practical 



men." 



A grid with a clear opening of two to two and a half feet square, 

 through Avhich air is sent at the rate of three feet per second, will 

 change the entire atmosphere of an ordinary London house every 

 hour; and a good-sized coke or well-constructed German stove will 

 heat this volume of air from 65 to 70, and maintain a temperature 

 throus;hout such house of 50 to 55. 



The bulk of the heat so generated will be utilized and diffused. 

 The excessive loss of heat from fireplaces will be changed to use, and 

 economy will be the rule instead of a waste excessive, continuous, 

 and expensive. And the whole of it will be in substitution not in 

 excess of an undisturbed open fire-grate consumption of fuel, and 

 this by a process of natural selection and persuasion. With a fairly 

 equable temperature of .50 to 55 throughout the house, and highest 

 where now it is usually lowest the hall and passages the demand for 

 large open fires subsides. Small fires become the rule, and their going 

 out the difficulty. There will be no dread of draughts from open doors ; 

 no peevish injunctions to "shut that door;" no huddling over a hot 

 fire, scorched on one side and chilled on the other ; no breathing at 

 one moment of air at 100, and the next, and without preparation or 

 much gradation, one of 40. In short, " the bull will be taken by the 

 horns " and tamed. We have made friends of our foes, and we may 

 cry Eureka ! for the problem will be solved ! 



Now for the possible objections. We shall probably be told that 

 stoves are unwholesome that they spoil the air and make the warmed 

 space " close." Our reply is, that stoves in unventilated rooms do all 

 this, and more. They are usually unsightly, and tliey even the most 

 economical rob the room of the bright, cheerful, moral influence of 

 warmth with light. But none of the objections to which stoves are 

 liable attach to their use under the arrangement we advocate. The 

 stove is not placed in an vmventilated room, hut in a strong draught. 

 No particle of air ever gets warmed twice over. None {^forced into 

 contiguity with the heating surface. It takes up as it passes that sur- 

 face its modicum of caloric, and wings it way to impart it to all and 

 everything of a lower temperature than itself; and finally it escapes, 

 when fairly deprived of it, by nicks and crannies and illegitimate out- 

 lets, as well as by those prearranged for the best effect. Hence there 

 are no whistling shreds of frosty air, harbingers of colds, catarrhs, 

 toothache, earache, and neuralgic inflictions; no "sulphuring" from 

 down-draughts in unused bedroom-fires; no shiversome " draughts" 

 from open doors. By admitting air round about our heat-generator, 

 full, free, and unconfined, we adopt the principle of the steam-engine 

 governor. If the stove be overheated from negligence, the drauglit 

 becomes quicker, the particles of air are heated sooner, but not neces- 

 sarily much more. If the stove-fire is allowed to get low, each par- 



