STRUCTURES ADAPTED TO PARTICULAR PURPOSES. 67 



upon which it is made is undoubtedly good ; a principle which 

 may easily be illustrated by placing a few common frame- 

 sashes in the positions of the supposed ridge-and-furrow roof, 

 placing some tender-foliaged plants beneath them, and then 

 comparing the results, under intense sunshine, with the effects 

 produced under a common sash, whose surface is perpendicular 

 to the noon-day sun. 



Whatever might be said in favor of cold vineries, they are, 

 nevertheless, subject to casualties which are necessarily una- 

 voidable. This is more especially the case in the Northern 

 States ; and even as far south as the latitude from which we 

 now write, (39 45',) they are liable to the same mishaps. All 

 houses for the production of foreign grapes should have some 

 means or other of commanding a little artificial heat when it is 

 found absolutely necessary. This does not amount to saying 

 that good crops have not and may not be grown in cold-houses, 

 without any means of raising the temperature in cold nights ; 

 yet it cannot be denied that good crops have been sacrificed for 

 the want of a slight fire in frosty nights. This is particularly 

 the case in nectarine and peach houses, where we have seen the 

 crop completely destroyed in a single night. 



Experience has fully shown that the culture of exotic fruits is 

 a precarious business, without some readily available means of 

 averting those evils which are neither modified nor averted by 

 any peculiar mode of construction, or any angle that can be 

 given to the roof. This circumstance is worthy of particular 

 attention, as many persons who design hot-houses lay particular 

 stress on certain trifling details in the structure, which, in a 

 practical point of view, are unworthy of the least notice. 



We have lately had some conversations with men thoroughly 

 skilled in the science, as well as the practice, of vine-growing 

 and the details of hot-house management, and have particularly 

 noted the diversity of opinion regarding the upright portion of 

 the front of the house. Some are of opinion that hot-houses for 

 the culture of fruit should have no parapet-wall, but that the 

 sashes should rest on a water-plate level, or nearly level, with 

 the ground, giving, as a reason, the fact that the parapet pre- 

 vents the sun and light from getting to the inside border, and to 



