Max 9, 1012. 



The Weekly Florists' Review. 



be built were those for Jay Gould, at 

 Irvington-on-Hudson, N. Y. Here the 

 cast iron sills, iron rafters and purlins 

 capped with wood were used to sup- 

 port the superstructure. The principle 

 of this construction today is still used 

 on all iron and steel greenhouses. The 

 details may be changed, but the prin- 

 ciple of having the iron or steel frame- 

 work on the inside of the greenhouses, 

 with all members on the outside which 

 receive the glass, of wood, is the same. 

 This construction, after repeated ex- 

 periments, has proved to be the most 

 durable and suitable to our variable 

 climate and has stood the test well. 



The next important step in the con- 

 struction of commercial greenhouses 

 was the introduction of what is known 

 as the cast iron footpiece construction. 

 A post or footpiece made of cast iron 

 was placed in the ground about thirty 

 inches, and to these steel rafters were 

 bolted. The sides, up to within two 

 feet of the eaves, were built of two 

 thicknesses of boards, with building 

 paper between. This made a cheap 

 and substantial construction. 



Next, wooden gutters and eaves 

 plates were dropped out and angle 

 iron used in place of the wood plate. 

 The eaves plate is fully one-third 

 smaller than the wood one and many 

 times as strong; it strengthened the 

 greenhouse at its vital point. The bars 

 and rafter caps were fastened to this 

 angle iron with a small cast iron fit- 

 ting. The eaves plate, having part of 

 its surface exposed to the inside tem- 

 perature of the greenhouse, conveys the 

 heat to the outside surfaces and, to a 

 certain extent, prevents the formation 

 of icicles on the outside. Certainly it 

 was and is a great improvement over 

 the wood plate, which was one of the 

 first members in a greenhouse to decay. 



Larger Glass Comes In. 



During all this time the distance 

 between the rafters has steadily in- 

 creased, the wood members being made 

 smaller and the width of the glass in- 

 creased. From glass six inches wide 

 to twenty-four inches is the history, 

 although for many reasons of economy 

 glass sixteen inches wide has been and 

 is generally used.. The light admitted 

 has been greatly increased. There is 

 no perceptible difference in the amount 

 of light in a house glazed with 16- 

 inch and 24-inch glass, and the major- 

 ity of the leading growers claim the 

 growing qualities are approximately 

 the same. Most people prefer the 16- 

 inch, as it costs less to replace a broken 

 light, and also a tighter roof can be 

 made with this width glass. If you 

 examine the edge of a light of glass, 

 you will notice that the glass is wavy 

 and not perfectly straight, so that 

 when two lights of glass are lapped you 

 will find that there is a certain amount 

 of open space between the lights of 

 glass. The wider the glass the more 

 uneven it is. 



With the light construction now used 

 I do not believe it makes any differ- 

 ence in cases where a greenhouse is 

 used for growing a general assortment 

 of plants whether a house is built fac- 

 ing south, east or west, providing there 

 are no trees, hills or other objects to 

 shade the house. The topographical 

 conditions of the site play an impor- 

 tant part in the location. As these 

 usually vary in each case, each case 

 requires individual consideration. Of 

 course where growers desire a green - 



A Houte of Gittleya Schroederae at the Dale Estate, BratnptOD> Ont. 



house for roses or carnations, etc., as 

 a specialty, more consideration and at- 

 tention is given in this direction. More 

 sunlight is obtained by placing the 

 greenhouse east and west, so that the 

 sun at noon, when at its strongest, 

 shines directly between the bars and 

 rafters in the roof. I understand from 

 some of the largest rose growers that 

 it is an advantage to place the house 

 from 10 to 15 degrees north of east 

 in order to get the advantage of 

 the morning sun a trifle earlier. The 

 morning sun is, of course, more bene- 

 ficial than the afternoon sun, it being 

 an advantage to start vegetation as 

 early in the morning as possible. 



The Width Still Increases. 



As the glass has increased in width, 

 so has the width of the houses, so that 

 now houses thirty, forty, fifty, fifty- 

 five, sixty and seventy-two feet wide 

 are common. Some have been built 

 over 100 feet in width, but in order 

 to reduce the height of the ridge as 

 much as possible the roofs are usually 

 designed with a flat pitch. It is doubt- 

 ful if houses as wide as this are a 

 success unless built on a sloping 

 ground, so that the roof can have suf- 

 ficient slope to properly shed the wa- 

 ter and not have a shower on the 

 inside of the greenhouse as well as on 

 the outside. 



A pitch of 32 degrees in houses up 

 to thirty feet in width is preferable, 

 and in those from thirty to fifty feet 

 28 degrees has been found a good angle 

 for roofs; 26 degrees is satisfactory 

 for houses fifty feet wide and over. 



Now as to supports: A 30-foot 

 house requires no columns. Those 

 thirty-five or forty feet wide require 

 two columns; fifty-five to sixty feet 

 width calls for four columns, and sev- 

 enty feet calls for six columns. Houses 

 seventy or seventy-two feet wide re- 

 quire only four rows of columns if 

 they are used in combination with com- 

 pression trusses. 



There are some greenhouses con- 

 structed today in which the principle 

 of construction is to truss the roofs, 

 thus eliminating columns to a great 

 extent. This would be more satisfac- 

 tory if the trusses were constructed on 



a compression basis, but they are con- 

 structed to a large extent on a tension 

 basis, and depend upon all members 

 being constantly in tune, as it were. 

 Now there is considerable vibration in 

 a greenhouse roof and the constant 

 movement is bound to stretch the light 

 rods, etc., which are used in this con- 

 struction. As soon as one member 

 loses its tune, it puts all the others 

 out also, and I believe that a green- 

 house constructed on this principle will 

 deteriorate more rapidly than one sup- 

 ported by columns or with a combina- 

 tion of columns and compression 

 trusses. 



Semi-Iron or Pipe Frame Construction. 



We have been considering what is 

 known as the iron frame construction. 

 There is another type known as the 

 pipe frame or semi-iron construction. 

 The difference between the two is not 

 great, the difference being that the 

 steel rafters are omitted in the semi- 

 iron construction and the roof bars, 

 etc., are supported by longitudinal pur- 

 lins made of pipe or angle iron; 1 be- 

 lieve pipe is preferable, for the reason 

 that it casts the least amount of shade. 

 These purlins are in turn supported 

 by pipe columns. The painting and 

 glazing in this construction are the 

 same as in the houses where iron raft- 

 ers are used. There is a slight saving 

 in the cost of this house, as the steel 

 used is less and the parts require less 

 mill work. 



CATTLEYAS AT DALE'S. 



At the Dale Estate, Brampton, Ont., 

 there are eight houses, each 16x100 feet, 

 devoted to cattleyas. These houses con- 

 tain over 33,000 plants and it is said 

 that nothing on the place affords equal 

 interest for visitors. Perhaps one of 

 the reasons for this is that the Dale 

 people have had rather exceptional suc- 

 cess with orchids, the houses seldom 

 being without a brave show of bloom. 

 The accompanying illustration is repro- 

 duced from a photograph made in one 

 of the Dale houses just before Easter. 

 The variety is Schroederae. The splen- 

 did character of the crop will be ap- 

 parent at a glance. 



