194 VARIOUS METHODS OF HEATING DESCRIBED IN DETAIL. 



by the occasional opening of the door ; and in the severe weather 

 of our winters, with the thermometer below zero, this portion is 

 frequently small indeed. The pleasure and ability of exercising 

 our physical functions in cold weather, will be in exact propor- 

 tion to the frequency of practice ; and it is truly surprising, that 

 with so much positive proof of direct injury resulting from con- 

 tinued confinement over highly heated stoves, many will, never- 

 theless, persist in so pernicious a custom, a custom which is 

 truly national, and which renders the influence of these stoves 

 as baneful as that of the Upas tree, and sends thousands an- 

 nually to an untimely and premature grave. 



I have observed, by some articles that have lately appeared in 

 an excellent horticultural periodical, (Downing's Horticulturist,) 

 that this much talked of system of warming horticultural struc- 

 tures with hot air, called Polmaise, has been adopted by some 

 individuals in this country. These individuals have been misled 

 by the extravagant statements, or rather raw-statements, that 

 have from time to time appeared in the Gardener's Chronicle, 

 (of England,) by its talented editor and others under his influ- 

 ence. Those who have been in the habit of reading that paper 

 in this country, and noticed the laudatory articles that have so 

 frequently appeared in it, in favor of this method, yet unac- 

 quainted with the practical opposition it has received by num- 

 bers of experienced men, in every way qualified to decide upon 

 its merits, can scarcely be blamed for adopting a system said to 

 possess so many advantages over all others ; and when it is con- 

 sidered that the gardening journal, which represents the opinions 

 of practical men in that country, is but little read in America, 

 in fact, I may say, almost unknown, save by a few individuals, 

 it is not surprising that they should have been betrayed into the 

 system supported by such authority. It is difficult, indeed, to 

 account for the strong-headed and one-sided policy of the advo- 

 cates and promoters of Polmaise. The fact is well known, that 

 the system, and the defects connected with it, were thoroughly 

 established many years before it was applied at the place from 

 which it takes its name. In many places it had been tried, and 

 found inferior, and far more fickle than the common smokf 



