GREENHOUSES. 



385 



Fig. 521. 



parts, the opening being 6 inches wide, 

 and extending the whole length of each 

 ridge. Fig. 521 is a section 

 on C D. 



The front elevations — for 

 all the sides are alike — of 

 such a structure would 

 present a straight line of 

 columns in any style of 

 architecture suitable to the 

 situation and surrounding 

 objects : their capitals and friezes would 

 form a parapet not much exceeding the 

 top of the ridges, which would give a fin- 

 ished appearance to the whole, and hide 

 the roof, which, in most conservatories 

 upon architectural principles, is very ob- 

 jectionable. The panelling or frieze be- 

 tween the capitals should be of glass, 

 giving greater apparent height to the eleva- 

 tion, and casting less shade than if it 

 were constructed of opaque substances, 

 such as wood or iron. 



We have submitted this style of roof 

 to a high engineering authority, who 

 states that there would be no difficulty 

 in constructing such roofs to any extent 

 in length, and from 100 to 150 feet in 

 width, and probably even more. Those 

 we have consulted have now prepared 

 more detailed drawings and calculations 

 than is necessary for our present purpose, 

 and are ready to construct such roofs 

 upon the shortest notice. 



§ 2. — GREENHOUSES. 



The greenhouse differs from the conser- 

 vatory, principally in containing smaller 

 plants, and these for the most part being 

 in a portable state ; and also in being a 



house of smaller dimensions, and without 

 architectural pretensions. Of all forms 

 for a greenhouse, that of a lean-to is 

 decidedly the worst, and that of the span 

 or curvilinear the best. Peaches and 

 vines may be grown to the greatest degree 

 of perfection in lean-to houses ; but green- 

 house plants seldom can, as the merits 

 of the latter greatly depend on the 

 symmetry of form— and this cannot be 

 attained unless every part of the plant is 

 equally exposed to light, air, and sun- 

 shine. It is true, there are many plants 

 that will thrive with much less light than 

 others ; but they are few in number com- 

 pared with the thousands in cultivation. 

 This we learn from the great book of 

 nature, where we see how profusely she 

 has clothed the mountain, the valley, 

 and the open country; while the forest 

 and the shady dingle are comparatively 

 barren — at least so far as number of 

 species is concerned. The orange, the 

 myrtle, and the camellia, will thrive where 

 the extensive generas Erica, Pelargonium, 

 &c., will not long exist. 



It seems now almost universally ad- 

 mitted that the span or curvilinear form 

 of roof is best adapted for this purpose, 

 and that the ends of the houses should 

 front the north and south, although, 

 under peculiar circumstances, they may 

 be usefully constructed to face the east 

 and west ; the more so if they are glass 

 on all sides to within a foot or so of 

 the ground, as in most of the annexed 

 illustrations. 



In regard to elevation, fig. 522 is sup- 

 posed to be of woocl, standing on a plinth . 

 or basement 18 inches high, the better 

 to secure the framework from decay. 

 The pilasters are hollow, as is usual in 



Fig. 522. 



VOL, 



3 c 



