22 



The Weekly Florists' Review. 



Max 9, 1012. 



iiiiiiiniiiiiii iiiMiiiiiiiiiiiiiiiiiiiiiiiiiiijijiiiiiiiiiiiiiiiiiiiiiiiiiiiin iiiiiiiiiii i iiiiiiiiiii iiiiiii iiiiiii ii 



'^^WW^^^^ 



GREENHOUSE 



CONSTRUCTION 





.. . f.. .. i imn> n i H P»iiin>niii»i»» m nTnrr 



PBOOBESS OF FIFTY YEARS. 



The Earliest Houses. 



It is a long step from the cumber- 

 some greenhouse of fifty years ago to 

 the modern, cobwebby structure of to- 

 day. The early greenhouses were gen- 

 erally built against a high wall, the 

 wall being on the north side. This 

 was quite a factor in supplying heat 

 during the night. You know how a 

 piece of masonry will absorb heat when 

 exposed to the warmth of the sun, and 

 how warm it feels for a long time after 

 the sun has ceased to shine upon it. 

 So these high walls absorbed the heat 

 and gave it up to the greenhouse dur- 

 ing the night. In those days the only 

 method of heating was by means of 

 stoves, or a long flue, either of pipe 

 or masonry, extending the entire length 

 of the greenhouse, through which 

 heated air generated by a furnace or 

 flue heater was attempted to be car- 

 ried. This method of heating was not 

 satisfactory for the reason that unless 

 the flues were frequently gone over 

 and repaired there was always the dan- 

 ger of their giving out, which meant 

 a serious loss of plants damaged by 

 the gases and fumes which would es- 

 cape into the greenhouse. This arrange- 

 ment of heating was also unsatisfac- 

 tory for the reason that that portion 

 of the flue nearest the heater was nat- 

 urally the hottest and the farthest end 

 the coolest, which made it impossible 

 to secure an even temperature through- 

 out the greenhouse. Later this trouble 

 was overcome to some extent by a hot 

 water heating system arranged by 

 placing a pipe 'coil inside the heater 

 and connecting same by mains with 

 heating coils placed at the coolest end 

 of the greenhouse. Finally the flue 

 heater was abandoned entirely and the 

 heating accomplished altogether by a 

 hot water heating apparatus. 



Now as to the construction of the 

 superstructure, a heavy wood sill was 

 placed on top of the front wall. Heavy 

 wood rafters were placed about three 

 feet apart, extending from the sill to 

 the ridge, and sashes glazed with glass 

 only six inches wide were placed in 

 the roof. The top sashes were ar- 

 ranged to slide down for ventilation 

 and were operated with a system of 

 ropes and pulleys. 



Progress Begins. 



The crops raised in houses of this 

 type were far from satisfactory, as 

 you can readily realize, as with the 

 amount of wood in their construction 

 and the narrow glass, the percentage 

 of light admitted was small, to say 

 nothing of the cold air admitted 

 through imperfect construction. Later 

 full span houses were built of similar 

 construction. 



Mr. Lord, who was the founder of 

 the Lord & Burnham Co., was a great 



An extract from an illustrated lecture by Mon- 

 tague C. Wright, of Lord & Burnbam Co., before 

 the Florists' Club of Philadelphia, May 7. The 

 address was over 7000 words, or more than four 

 pages of The Review, which precluded publication 

 in full. Some sixty slides were used. 



lover of flowers and also a thorough 

 mechanic. He had a small greenhouse 

 in his yard which he had built him- 

 self. Mr. Lord became dissatisfied with 

 the results obtained and made up his 

 mind that if horticulture was to make 

 any progress it would be necessary to 

 greatly imprpve the construction of the 

 greenhouse, so he built himself a house 

 which proved to be so far ahead of 

 anything then known that his services 

 were soon in demand among the local 

 community. It was not long before 

 the success attained in these new 

 houses spread beyond these narrow lim- 



its and the greenhouse business, as a 

 business by itself, was launched. 



It has continued from that time to 

 grow until it has reached its present 

 proportions. The outlook for its con- 

 tinued expansion, improvement and 

 stability is bright indeed. 



The principle of the construction 

 adopted and built by Mr. Lord is the 

 same as is universally used today, 

 namely, building the roof as a per- 

 manent structure, with ventilating sashes 

 at the ridge. This method increased 

 the amount of light in the greenhouse 

 and also furnished a weatherproof con- 

 struction. Methods of supporting the 

 roof members are today numerous, but 

 they all are simply a means of making 

 the principle stated above stable and 

 lasting. In the early days there was 

 no glass on the sides. Walls of brick 

 or stone were built and the roof sprung 

 directly from the top of these walls. 



The inside level of the greenhouse 

 was generally on a lower level than 

 the outside grade. This was done to 



reduce the surfaces exposed to the out- 

 side air as much as possible. Most of 

 the houses were narrow and the plant 

 benches were so close to the glass that 

 it was impossible to grow plants of 

 any size except on the inner edge of 

 the side benches and in the center 

 benches. 



The next step forward was to make 

 the roof curved instead of straight. 

 The roof was constructed with two 

 radii, the lower one being about eight- 

 foot radius, the upper forty-five feet. 

 This gave more room for the plants 

 on the outer sides of the side plant 

 beds. The glass was not bent, but 

 short lights were used and as the 

 radius was large compared to the 

 length of each light, the difficulty was 

 solved the same as in building a curved 

 part to a brick house with ordinary 

 straight brick. 



With the introduction of hot water 

 and steam as a heating medium it be- 

 came possible to increase the width of 

 greenhouses, and houses twenty feet 

 and twenty-five feet in width became 

 common. This gave room for center 

 plant benches.. Next came the intro- 

 duction of glass on the sides, increas- 

 ing the height from the walk level to 

 the gutter line. By doing this it was 

 possible to build the roof without the 

 curve and still have room on the side 

 benches for medium-sized plants. The 

 masonry wall was cut down to almost 

 grade and wooden ventilating panels 

 about two feet high placed on the sides 

 below the top of the plant bench. This 

 in a measure is an ideal way of ven- 

 tilating a house where side ventilation 

 is required, as the cool air from out- 

 side has to first pass over and around 

 the heating pipes, which takes the chil) 

 from the air. 



The Introduction of Iron. 



At that time commercial houses were 

 built with locust posts, set about three 

 feet in the ground, four feet above 

 and boarded up to the eaves. As the 

 tendency towards wider houses in- 

 creased and wood decreased in quality, 

 it became necessary to find some mate- 

 rial that would take the place of that 

 then in use. Iron and steel as a build- 

 ing medium was at that time attract- 

 ing attention and to this metal atten- 

 tion in the construction of greenhouses 

 was turned. Cast iron sills for cap- 

 ping the masonry walls were therefore 

 substituted for the three-piece wood 

 sill. Iron rafters were substituted in 

 place of the heavy wood ones. These 

 iron rafters are capped with wood 

 grooved to fit over the rafters and de- 

 signed to receive the glass. By cover- 

 ing this portion of the steel frame 

 with wood, all trouble from expansion 

 and contraction of metal is avoided. 

 Iron purlins were also substituted in- 

 stead of wooden ones. 



The first iron frame greenhouses to 



