ON CURVILINEAR IRON ROOFS TO HOTHOUSES. 267 



lest seconds. Green glass might be afforded on much lower terms ; but I 

 do not recommend it, being confident that in our climate pine-apple 

 plants suffer a hundred days by want of light, for one in which, with 

 proper care, they sustain injury by excess of it. 



LI. -A NEW AND IMPROVED METHOD OF CULTIVATING THE MELON. 



{Read before the HORTICULTURAL SOCIETY, November \bth t 1822.] 



I HAVE described, in a preceding paper*, a new kind of hot-bed, into 

 which, by means of a hollow wall, a heated current of air is made at all 

 times to enter, without any mixture of the vapour arising from the fer- 

 menting material ; and in which the temperature is raised and supported 

 by a rapid change of air, instead of being lowered, as it is in every other 

 kind of hot-bed with which I am acquainted. 



My object in the construction of this hot-bed, was the culture of the 

 pine-apple ; but I employed it in the last summer in raising melons ; and 

 I succeeded so much more perfectly than I had ever previously done, 

 that I am led to hope the following account of the mode of culture 

 adopted, will be honoured by the approbation of the Horticultural 

 Society. 



Before I began to raise my melon plants, I calculated, as I think every 

 gardener ought to do, who cultivates this fruit, the amount in weight 

 which I might expect to obtain in perfection, from a given extent of 

 glass roof. The heaviest crop of good grapes, which I had ever seen 

 growing in a forcing-house, did not appear to me to exceed a pound to 

 every fifteen inches square of glass roof, taking into the admeasurement 

 every part of such roof. The vines had, in such cases, lived through 

 many successive seasons, and possessed a large extent of roots and 

 branches, everywhere amply stored with the true sap, or living blood, of 

 the plant generated in a preceding season, and possessing powers rela- 

 tive to vegetable life analogous to those of the blood of torpid animals. 

 Their blossoms and minute leaves had also been the product of the labour 

 of a past season. The melon plants had, on the contrary, everything to 

 accomplish, not only in a single season, but in a small part of such sea- 

 son ; and therefore I considered a pound of fruit to every fifteen inches 

 of glass roof, to be the largest amount of perfect fruit upon which I could 



* See above, page 262. 



