1398 



GREENHOUSE 



GREENHOUSE 



ried into the ground about 30 inches. Today, light con- 

 crete walls about 4 inches thick are built. The cost of 

 the concrete is almost the same as double boarding but 

 has the advantage of being iudestructible. 



Framework. 



The construction best adapted for conservatories, 

 park houses and greenhouses, and for private places 

 where the improvements are desired to be permanent 

 in character and attractive in appearance is the com- 

 bination of iron and wood. In this system, the main 

 frame which supports the weight and strain 

 is of iron, or steel, wood being used in the 

 frames as a setting for the glass and to 

 form a non-conductor of great advantage in 

 the heating of the house. The iron work in 

 this style of construction usually 

 consists of cast-iron sills capping 

 the foundation walls, wrought-iron 

 rafters setting on the sills, about 8 

 feet apart and running from sill to 

 ridge, forming the side post and 

 rafter in one piece, cast-iron gutters, 

 and angle iron purhns between the 

 rafters, all securely bracketed and 

 bolted together, forming a complete 

 framework of metal, light, strong 

 and durable. The wood used con- 

 sists of light sash-bars for support- 

 ing the glass, sashes for ventila- 

 tion and doors. This woodwork 

 being entirely supported by the 

 metal frame, and not being used 

 where it will be continually wet, wiO 

 be found as durable as any other material, and for many 

 reasons better adapted for the requirements of a green- 

 house roof. This combination system of metal and wood 

 construction has been extensively adopted by florists, 

 growers of cut-flowers and also the progressive vegetable- 

 growers. In the houses built for the above, the masonry 

 foundation walls are omitted. Posts constructed of 

 wrought-iron are placed in the sides extending from 

 about 30 inches below grade to the height of the eaves. 

 These posts occur at every rafter, to which they are 

 connected with steel or cast-iron fittings. The posts 

 are embedded in concrete below grade, and 4-inch con- 

 crete walls built extending from 6 inches below grade up 

 to the under side of the glazing siU. 



Gutters are seldom used at the eave line in this type 

 of house. An angle-iron eave-plate is substituted for 

 the gutter so framed as to allow the snow and ice to 

 ehde over it, keeping the roof entirely clear from 

 such accumulations which darken a house in winter. 



The first cost is somewhat increased over an all- 

 wood construction, but in view of its greater durability 

 and saving in repairs, it will be found in the end, the 

 better investment. 



Cast-iron gutters are provided to collect the rain- 

 water from the roof. By exposing the inner side of 

 these gutters to the heat of the house, they are kept 

 free of ice in the winter. Small metal 

 clips fastened with screws are used 

 to connect the wood sash-bars 

 to the cast-iron gutters, 

 angle-iron plates and 

 purlins. This 



method of securing the sash-bars in place is very con- 

 venient in case of repairs, and renders the structure 

 practically portable. A careful examination of any old 

 greenhouse will show that the parts of the frame which 

 decay first are those pieces of wood which are joined 

 together, for water penetrating the joints soon destroys 

 the wood. This trouble is 

 largely avoided by arrang- 

 ing the frame so that each 

 piece of wood is fastened 



1754. A very wide plant-grower's house. 



1753. Even-span curvilinear greenhouse, with cast-iron piping. 



directly to the iron frame instead of to another piece 

 of wood. Joints between wood and iron do not rot the 

 wood, the latter being preserved by the corrosion of 

 the metal. 



The curvihnear form of house (Fig. 1753) is ornamen- 

 tal and particularly well adapted for conservatories, 

 palm-houses and show-houses of all kinds. It is pre- 

 ferred for vineries and fruit-hoUses, as the form allows 

 the canes to be supported on the line of the roof with- 

 out a sharp bend at the plate line. The light in a 

 curved house, being admitted at different angles, is 

 better diffused and more natural than when reflected 

 through a long pane of straight glass. The cost of a 

 curved roof is slightly greater in the construction, but 

 the arched frame is stronger and will keep its shape 

 better than a house with straight lines, thus largely 

 compensating for the extra cost. For special purposes 

 and locations, special forms of frames may be used. 

 Good forms of commercial houses are shown in Figs. 

 1754-56. 



The ridge-and-furrow type of house (Fig. 1757) is sel- 

 dom built now except in cases in which the amount of 

 land available is limited. The superior growing quali- 

 ties of greenhouses built separately has been thor- 

 oughly demonstrated, as has also the increased produc- 

 tiveness of wide houses. A florist now seldom builds a 

 house less than 30 feet wide. It is oftener 40 feet, and 

 houses 55, 65, 75 and 85 feet wide are not imcommon. 

 These wider houses cost less in proportion to build, 

 grow better crops and are more economical as to 

 labor (Fig. 1754). 



Greenhouses with curved eaves (Fig. 1756) 

 are being built more and 

 more. This type presents a 

 pleasing appearance and 

 eliminates s h a d e - casting 

 members at the eaves. A 

 combination sill and gutter 

 is substituted for the plain 

 sill on top of masonry wall to 

 which the rafters and bars 

 are secured. 



