13 



mitted to an artificially elevated temperature, to the chil- 

 ling influence of cold air, which is admitted whenever the 

 sashes of an ordinary frame or of a pit, are opened, in order 

 to bestow these necessary attentions. It may be urged 

 that a dung bed has still the advantage, on the ground of 

 economy ; but when a fair calculation is made of labour 

 and loss or anxiety on the one hand, and of duration on 

 the other, such an assumption, will be quite untenable. 

 Neatness, convenience, certainty, and economy, are the 

 principal points of advantage which are gained by the 

 adoption of pits heated by means of hot water, over those 

 of a structure, depending for its supply of heat, on the 

 aid of fermenting masses; whilst the attainment of a still 

 greater degree both of convenience, and of certainty, 

 which may be secured by cultivation in forcing houses, 

 point out at once the advantages which render such 

 houses, preferable to pits. 



The application of the gutter system of heating, was 

 not long since thought to be an improvement of great 

 importance, and there can be no question but that it 

 affords a means of regulating the moisture of the atmos- 

 phere of hothouses, in conjunction with the temperature, 

 which prior to its introduction had not been attained; 

 and as such, it is worthy of extensive adoption : it re- 

 quires however some judgement in its adaptation to parti- 

 cular structures, and to render, it suitable, to effect any 

 particular object for which it may be employed. 



The tank system as a means of applying bottom heat, 

 employed either in conjunction with the gutters, or with 

 ordinary piping, to supply heat to the atmosphere, is the 

 most important advance which has hitherto been made 

 towards supplying the wants of those plants, which re- 

 quire such peculiar aid; and with reference to the Cucum- 

 ber, it may be regarded as furnishing a new era in its cul- 

 tivation. 



B 5 



