GREENHOUSE STRUCTURES. 79 



most convenient for the working of the plants ; if nar- 

 rower, too much space would be lost ; if wider, the fur- 

 ther side of the benches could not be reached easily. 



The width of the walk, however, must be determined 

 by what the greenhouses are designed for ; if for workmen 

 merely, two feet, or even less room, will do for the walk ; 

 but if visitors are to be accommodated, it should be at 

 least two feet and one-half in width. 



A brick shed (A) covers the boiler pit (F), and is 

 attached to the north end of the houses, the back wall 

 being about twelve feet high, the front eight feet, width 

 sixteen feet ; besides breaking off the north wind from 

 the greenhouses, we find this shed indispensable as 

 a potting and packing room. It will be understood that 

 these greenhouses have their ends north and south ; con- 

 sequently one side is exposed to the east in the morning, 

 the other to the west in the afternoon, while at noonday 

 the rays of the sun strike directly upon the apex of the 

 roof. There is nothing arbitrary in having the green- 

 houses end north and south ; a point to the east or west 

 would not make any material difference, but, if circum- 

 stances will admit, we prefer them to end direct north 

 and south. 



.At present prices, built in a plain, substantial manner, 

 with the outer walls of brick or stone, and heated with 

 hot water, they will cost about $8 per running foot, or 

 $2,400 for the three connected that is, the range of 

 three greenhouses 100 feet long by thirty-three feet wide, 

 together with the shed to cover the boiler-pit ; if put up 

 singly, the cost would be at least ten per cent. more. If 

 walls are formed of wood, which we now prefer, the whole 

 cost might be lessened ten or fifteen per cent. 



Another plan in use is shown in figure 17, combining the 

 flue and boiler, from the same furnace. This is the most 

 economical plan in which hot water can be used. As 

 shown in the engraving, there are two houses joined 



