Systems of Warming and Ventilating Buildings. 337 



that happens to fall upon the stove, and it always has more or less 

 of a burnt odour, arising from the necessarily high temperature of 

 the surface of iron over which it passes, and from which it receives 

 its supply of heat. We also have doubts of its safety in certain 

 situations. 



Of Mr. Silvester's system of heating and ventilation, we can 

 speak with less equivocal praise ; but, it is much more expensive, 

 and owing to the stupidity of architects and builders, more difficult 

 of application. A description of it will be found in the inventor's 

 account of the Derbyshire General Infirmary*, with drawings il- 

 lustrative of its construction. We must satisfy ourselves here 

 with a brief account of the principles of the contrivance. 



It is necessary that the stove should be erected on the basement 

 story, or, if possible, below it. It consists of a square wrought- 

 iron cockle, in the interior of which is the fire, and which is sur- 

 rounded by brick-work of the same shape, there being a space of 

 about six or eight inches left between the cockle and brick-work. 

 The air to be heated is brought from without, and conveyed by a 

 number of tubes which pass through the lower half of the brick-work 

 and terminate within less than an inch of the cockle, and it is dis- 

 charged through a similar set of tubes, which perforate the upper 

 half of the brick-work, and terminate in what is called the hot- 

 air chamber, a cavity from which an upright flue issues to carry 

 the heated air to its destination. The cold air, therefore, is twice 

 brought close to the heated cockle, first, upon its entrance, and 

 then upon its exit, and it is never made very hot, but a very large 

 quantity of moderately -heated air is driven up the air-shaft or flue ; 

 the air never, as far as we have perceived, has any disagreeable 

 smell, nor can it, in consequence of the construction of the fire- 

 place, be at any time over-heated. We have remarked the neces- 

 sity of placing this stove considerably below the rooms or hall and 

 staircase to be heated ; from fifteen to twenty, or even thirty feet, 

 is desirable where it can be obtained, in order to ensure a rapid 

 current: for the velocity of the heated air is not only as its tempe- 

 rature, but also as the square root of the height. Matters should 

 be so adjusted in this respect, as not to suffer the heat of the 

 cockle to exceed on any occasion 300°. 



Whenever stoves of the description we have described, are em- 

 ployed for heating rooms, or close apartments of any kind, effectual 

 means should be at the same time resorted to, to secure a perfect 



* The Philosophy of Domestic Economy, as cxemplitieil in the mode of 

 warming', ventilating, washing-, drying;, and cooking-; and in various arrange- 

 ments contributing (o the comfort and convenionce of domestic life, adopted 

 in the Derbyshire General Inlirmary ; and more recently on a greatly extended 

 scale in several other public buildings newly erected in this country; together 

 with an explanation of the principles on which they are performed. By 

 C. Silvester, Engineer. 1819. Longman. 



