Mr. Langton on Artificial Climates. 367 



tage for this purpose, from being so bad a conductor of heat ; 

 the annual expenses of keeping up the required temperature 

 would from this circumstance be reduced about eight per cent 

 by using wood in preference to iron for this purpose. 



In estimating the cost of such an establishment, it appears 

 quite unnecessary to calculate the expense of building the 

 houses, that expense having no reference to the peculiar ex- 

 penses of the place, except their being fire-proof, which cir- 

 cumstance, from cast-iron being at present so remarkably 

 cheap, and from such quantities of exactly similar castings 

 being required, would add extremely little to the cost of con- 

 structing houses of the same class without the advantage of 

 that protection to life and property. The first expenses pe- 

 culiar to this establishment would be a glazed roof, if three 

 hundred feet square, of rather more than two acres, its fram- 

 ing and supports, and a very extensive apparatus for keeping 

 up an artificial temperature. The extent of glazed frames 

 would not exceed one hundred thousand superficial feet; this 

 at two shillings per foot for labour and materials would make 

 the glazed framing amount to ten thousand pounds. The 

 pillars, with the extending beams and skeleton frame of roof, 

 might a little exceed five thousand pounds : and the apparatus 

 for warming and ventilating the area would rather exceed 

 five thousand pounds more. The total cost therefore, when 

 painted and finished, may be expected at the outside not to 

 exceed twenty-five thousand pounds, or about seven hundred 

 pounds for each double house ; and this sum would doubtless 

 allow a sufficient surplus with which to stock the ground, at 

 least with vines, which intwining themselves up the columns 

 and crossing the spaces above, would afford shade by their 

 foliage as well as refreshment by their fruit. As for plants of 

 rarity and value, it may be found that individual liberality 

 may render the application of capital for their purchase whol- 

 ly uncalled for, nor should the means be wanting of perma- 

 nently recording acts of that nature. 



The annual expense of keeping up the required tempera- 

 ture will usually be in London about fourteen hundred pounds; 

 each foot of glazed surface requiring about one-fourth of a 

 bushel of coals per annum. This calculation assumes the 

 temperature to be kept up to about fifty-two degrees Fah- 

 renheit during the winter months ; it also supposes that no 

 more ventilation is allowed in very cold weather than what 

 escapes between the laps of the glass when well fitted, more 

 ventilation being only allowed for in mild weather; while in 

 hot weather most of the roof might be opened. The total ad- 

 ditional expense, including interest for money sunk, may 



therefore 



