HEATING BY STEAM. 



229 



air in a fit state for respiration. Another 

 improvement of Green's was to place the 

 pipes conveying the steam from the boiler 

 within other ones of larger calibre, ad- 

 mitting external air into the space be- 

 tween them to become heated ; which air 

 he conveyed to where the heat was most 

 wanted. The same gentleman also heated 

 a vinery and plant-house by steam at 

 Hammersmith, where it gave great satis- 

 faction. In 1793, Mr Butler, then gar- 

 dener to the Earl of Derby, heated melon 

 and pine pits by steam, by conveying it 

 under the bark or dung-beds, and allow- 

 ing it to escape amongst the pots — and 

 hence was the first of the profession to 

 apply it to forcing purposes. In the 

 same year, Mr Mawer, who had seen and 

 approved of these experiments, heated a 

 large range, consisting of seveD hothouses, 

 by steam at Dairy, near Edinburgh, 

 which had formerly been heated by 

 smoke-flues in the ordinary way. Con- 

 sidering how little was then known of the 

 principle of steam, it is not a little singu- 

 lar that Mawer's plan, although simple, 

 was practically so perfect. 



" The extension of the principle," says 

 Bernan in "History of Heating," &c, 

 "was much promoted by Mr Buchanan 

 of Glasgow, particularly by a pamphlet 

 that he printed on steam-heating, in 

 1807, and which he enlarged a few years 

 afterwards with a description of his appa- 

 ratus. Nothing of value to a practical 

 man, or in which he should have the 

 least confidence, has since been printed." 



Hay of Edinburgh, the eminent gar- 

 den architect, employed steam in and 

 after 1807, in many places in that 

 county where he was employed. De- 

 scriptions of his methods have appeared 

 in the " Memoirs of the Caledonian Hor- 

 ticultural Society." Various plans and 

 descriptions of steam-heating will be 

 found in "The Gardeners' Magazine/' 

 " Horticultural Society's Transactions," 

 &c. ; and it may be seen exemplified in 

 the most perfect way in the nursery of 

 the Messrs Loddige at Hackney, and the 

 plant-houses in the garden of the Duke 

 of Northumberland, at Sion House, Mid- 

 dlesex, both upon a very large scale, and 

 in various other places upon a more 

 limited one. 



The advantages of heating by steam 

 are thus given by Mr Loudon in " Ency- 



clopaedia of Gardening," p. 592 : — " It is 

 not, however, the genial nature of steam 

 heat which is its chief recommendation 

 for plant habitations, but the equality of 

 its distribution, and the distance to which 

 it may be carried. Steam can never heat 

 the tubes, even close to the boiler, above 

 212° ; and it will heat them to the same 

 degree, or nearly so, at the distance of 

 1000, 2000, or an indefinite number of 

 feet. Hence results the convenience of 

 heating any range or assemblage of hot- 

 houses, however great, from one boiler, 

 and the lessened risk of over or insuffi- 

 cient heating at whatever distance the 

 house may be from the fire-place. The 

 secondary advantages of heating by steam 

 are the saving of fuel and labour, and the 

 neatness and compactness of the whole 

 apparatus. Instead of a gardener having 

 to attend to a dozen or more fires, he has 

 only to attend to one ; instead of ashes 

 and coal, and unsightly objects, at a 

 dozen or more places, they are limited to 

 one place ; and instead of twelve paltry 

 chimney-tops, there is only one, which, 

 being necessarily large and high, may be 

 finished as a pillar, so as to have effect as 

 an object. Instead of twelve vomiters of 

 smoke and flakes of soot, the smoke may 

 be burned by using " one of the now many 

 smoke-consuming furnaces. " The steam- 

 pipes occupy much less space in the house 

 than flues, and require no cleaning. They 

 may often pass under paths where flues 

 would extend too deep. There is no dan- 

 ger of steam not drawing or circulating 

 freely, as is often the case with flues, and 

 always when they are too narrow or too 

 wide, or do not ascend from the furnace 

 to the chimney. Steam is impelled from 

 the boiler, and will proceed with equal 

 rapidity along small tubes or large ones, 

 and descending or ascending." 



Such are the advantages of heating by 

 steam, stated by one of its greatest advo- 

 cates. The following are the disadvan- 

 tages also given by the same authority : — 



" On a small scale, it is more expensive 

 than smoke flues, and more trouble is 

 required to attend to one boiler, than to 

 one or even two or three furnaces. It is 

 also somewhat more expensive than heat- 

 ing by hot water." 



Steam, as a medium of heating by it- 

 self, is far too volatile. It travels with 

 great rapidity, and gives out its heat 



