ARTIFICIAL HEAT AND APPARATUS. 47 
opposite currents are subject to check the even flow of the 
smoke, and drive it back. 
The Polmaise method of heating is a plan that origin- 
ated with a Mr. Murray, of Polmaise, in Scotland, and, like 
many other ingenious contrivances, was the result of pecu 
necessity. At the time of its introduction, it caused a 
great furor amongst the seekers after novelties, and like 
the fugacious follies of such persons, it soon fell into dis- 
repute with all, excepting those who were determined not 
to acknowledge their error. To say the best we can in 
its favor, it is only a modified flue. The principle, if so it 
may be called, consists in having a hot air chamber over 
and outside the furnace, and conducting the heat therein 
generated through one or more apertures into the house at 
at the other having a hole level with the 
floor, which forms the top of a drain that is conducted 
along under ground to the furnace, and which supplies the 
fire with fresh air to support combustion. By these means 
the heat from the chamber is drawn through the house, 
and a partial current produced, and from this it was at 
first predicted that a great benefit would arise, on account 
o near imitation to nature’s invigorating breezes. If 
glass was not a rapid conductor of = this Plausible 
