Wednesday Morotng, February 12 



GREENHOUSE COXSTRUCTIOX 

 A. C. Beal, Ithaca, Xew York 



I doubt very much if there is as much investment in any other line 



of agricultural enterprise where there has been so httle done in an 

 experimental way as in the construction of greenhouses. The time 

 has arrived when the national government or some leading states 

 should take up this subject and make a thorough study of it. When 

 we reahze that the value of the glass in the United States must be 

 something like fifty million dollars, and in New York State six 

 million, it seems to me it is a subject of sufficient importance to justify 

 some experimental work. 



This morning I intend to point out to you what some of the leading 

 types are. We may divide greenhouses into two general types, the 

 uneven span and the even span types. In the uneven span, we have 

 the lean-to type, the three-quarter span, the short span of the South, 

 and the various modifications. With the even span, we have various 

 forms of construction. We may subdivide them into the straight roof 

 type and cur^dlinear roof type. If we take the style of construction, 

 we have still other subdivisions. We have the wooden rafter house, 

 the iron frame house, in which the frame work is iron; we have the 

 sash bar type, in which no rafters are used; we have the semi-iron 

 type, in which a smaller amount of iron is used; and we have the truss 

 type of greenhouse. Then, there is the new type which has just been 

 offered by Hitchings & Company, where the rafter itself is trussed. 



I might say that the greenhouse has been developed from two 

 types of structure. We have the conservatories, those large, fine, 

 glass structures used for the housing of exotic plants. Those have 

 had a separate origin from the forcing type of structure. The forcing 

 house has been developed from the system of growing fruits upon 

 walls. (Professor Beal then showed a series of slides tracing the evolu- 

 tionof the various styles of greenhouse construction and pointed out 

 the advantages and disadvantages of the different types of modern 

 construction.) 



QrESTiox: What size of glass is used most? 



Professor Beal : Sixteen by twenty-four is used more than any 

 other size, not that it is necessarily better, but greenhouse men have 

 a preference for that size. 



