HORTICULTURAL SOCIETY OF LONDON. ^207 



average price of ^Os. a chaldron, and anthracite at 35i\ per ton, 

 we will find that the expense of heating the Orchidaceous house 

 in October last with coke was about .4*1. Ss. \0d., and the ex- 

 pense of heating it in November with anthracite Wiis £2. ; or if 

 we take the alternate days of Februar}^ 14 against 14,} we find 

 the expense of heating with ^8 bushel of coke 15*". 6d., and 

 16 cwt. of anthracite £\. bs. 7d. If we take the two months 

 in which coke was burned, against the two in which anthracite 

 was burned, which will not be fair owing to the nature of the 

 weather, the following are the results — Coke 3 chaldron 27 

 bushels, £A. Ins. ; Anthracite 3 ton, 1 cwt. -2 st. £4. ISs. 



These results speak for themselves so far as economy is con- 

 cerned, and therefore the only thing to be considered beyond 

 this is, which is most preferable with regard to management. A 

 measure of anthracite will last much longer than one of coke, 

 but the quantity of heat given out by each will be nearly the 

 same. In the month of December last when the weather was 

 very cold, it was not possible to keep the Orchidaceous house to 

 6(y with one boiler filled with the best anthracite, but this could be 

 done when coke broken into small pieces was used instead. 

 When both boilers were filled with anthracite this temperature 

 could easily be maintained, and they would last twice as long as 

 one filled with coke. So that it comes to this, equal bulk pro- 

 duces an equal quantity of heat, or at least, a chaldron of coke 

 will give out as much as a ton of anthracite, the one being 205. 

 the other 32s. But as anthracite does not burn so fiercely as 

 coke, it lasts longer and gives a very* steady heat. Ihis pro- 

 perty may make it desirable for Greenhouses where the expense 

 is not considered ; but in a stove with a well regulated conical 

 boiler, for every thing depends upon this, coke is not only the 

 cheapest of the two, but is much the easiest to manage, re- 

 quires less stoking, and burns clearer, as may be seen by re- 

 ferring to the quantity of ashes left by each. A mixture of the 

 two kinds in equal proportions answers ver\- well, with of course 

 intermediate results. 



The Orchidaceous house in which these experiments were 

 carried on was last year heated by a fiue, when we ■ ascer- 

 tained the following to be the quantity of fuel consumed, in the 

 month of February, viz. 



Fehruary. 



Thermom. 

 at S A.M. 



Thermom. 

 at 8 P.M. 



Lowest deg. 

 during- 

 night. 



Coal 



consumed 

 in 24 hours 











bush. 



19 



65 



64 



61 



2.i* 



20 



65 



65 



64 



2^ 



21 



65 



65 



65 



2 



22 



65 



65 



64 



2 



23 



66 



65 



65 



2 



24 



66 



67 



65 





25 



66 



67 



63 





* The weight ol the bushel used is 64 lbs. 



