380 First Report on the Experiments carried on 



experience, it was determined to counteract the irregularity of 

 temperature by providing the roof with an awning of canvas, 

 which might be drawn over the glass or removed, as should 

 be advisable. This produced very beneficial results. Peaches 

 and Nectarines appeared to sustain less inconvenience from the 

 nature of the house. Plums, Apricots, and some other more 

 hardy fruits have succeeded better, but Cherries have continued 

 to resist the attempts which have been made to force them in 

 it. The experiment therefore seems to prove, that, although 

 with attention it may be practicable to force some descrip- 

 tions of fruits, such as Peaches, Nectarines, Figs and Straw- 

 berries, perhaps with almost as much success as in a wooden 

 house, yet that others are not to be made to bear their fruit, 

 and that upon the whole, a house constructed with wood is 

 much better adapted to the purposes of forcing, than one 

 with a curvilinear roof of iron. 



Ventilation. After having said thus much of the hot- 

 houses in the Garden, with reference to their internal arrange- 

 ments, it may be proper to offer some remarks upon the 

 manner in which they are ventilated. Not that the mode in 

 which it is effected, is either absolutely new, or not known to 

 many of the Fellows of the Society, but because the method is 

 not so much adopted as it deserves to be ; and because the 

 advantages which have been experienced from it deserve to 

 be generally made known upon the authority of the So- 

 ciety. The way in which it is effected, was, it is believed, 

 first practised by Mr. Atkinson, who introduced it into the 

 construction of vineries with good effect. The contrivance 

 is this.— In the first place, the roof is not provided with 

 moveable sashes, but they are, on the contrary, fixed : there 



