LECTURES. 157 



ployed, and sufficient attention paid to the construction and manage- 

 ment of the grate. 



In explaining the peculiarities of stoves, Dr. Eeid insisted strongly 

 on the excellence of those long used in the north of Europe, that were 

 of considerable size, and had a pure porcellaneous surface. _ They 

 were much larger than the iron stoves usually emi)loyed in this 

 country and in England^ extent of surface compensating for the want of 

 intensity of heat, and the atmosphere they afforded being more 

 grateiul to the lungs and nostrils. Much ingenuity and skill were 

 imdoubtedly displayed in many of the stoyes made in this country 

 and the accompanying drums, but, as a general rule, the great ma- 

 jority he had seen were, when placed in the lower part of any building 

 for general purposes, usually provided with pipes or channels for the 

 ingress and egress of air that were tar too small. They gave accord- 

 ingly a sharp current at a high temperature rather than a large 

 volume of a mild atmosphere. They were also generally without the 

 means of sujjplying themselves with air from the house itself, instead 

 of from the external atmosphere, an ol))ect of great practical import- 

 ance in heating halls, passages, and public buildings previous to any 

 occupation, or where a small amount of ventilation was sufficient. 



Steam' apparatus was then adverted to, the use of which Dr. Reid 

 considered could be largely extended with advantages to individual 

 habitations, even where the power of using a common tire was secured 

 in the usual manner. It could be made to assume any desirable form. 

 The principal difficulty in ordinary habitations was the boiler within 

 doors. Great improvements had been made in modern boilers, so as 

 to reduce largely any risk of accident, but the im])r()vement consid- 

 ered most des'irable was, that in which one boiler should be provided 

 for a number of houses, and built in connexion with facilities for 

 water baths, washing, &c., and from which steam for heating or cul- 

 inary purposes coukfbe supplied to each individual habitation in the 

 same manner as gas, by special pipes. Steam, or steam power, could 

 be rented in many places for manufacturing pui-poses, and there 

 was no reason why similar facilities should ^ot be extended to ordi- 

 nary habitations in cities and villages. 



Steam could be made to afford any required temperature, according 

 to the form of apparatus used. With extended metallic rings, plates, 

 or projections from the surface of a steam pipe maintained at 212°, a 

 much lower temperature could be secured, corres})onding with^ the 

 amount of material in connexion with the pipe, and this form of ap- 

 paratus, or hollow metallic cases with a limited supply of steam, 

 necessarily gave a milder temperature. He did not consider a tem- 

 pe;-ature of 212° objectionable when the air was pure, though he pre- 

 ferred a milder warmth ; but higher temperatures, arising from the use 

 of high-pressure steam, he had often seen attended with disadvan- 

 tageous results, increasing with the elevation of tlie temperature 

 sustained. 



The action of the hot- water apparatus was then explained and illus- 

 trated by a glass model, in which colored water was thrown into cur- 

 rents by the action of heat, the warm water giving off caloric where- 

 ever it was desired, and then returning to the source of heat for a 



