STRUCTURAL 19 



course be governed to some extent by the class of plant it 

 is to contain. Cool house plants, and even so-called hardy 

 plants, when grown in pots, must have some fire heat 

 in winter. For such things two rows of 4~in. piping 

 running lengthwise and across one end of the house 

 would be sufficient. For the warmer greenhouse four 

 rows of 4~in. piping traversing the same distance would 

 be necessary. An approximate estimate is that I foot 

 of 4~in. piping will heat moderately 30 cubic feet of 

 space, but it should be borne in mind that it is far better 

 to have too much than too little piping, as the heat given 

 off to keep up a given temperature will be less fiery and 

 injurious in proportion to the additional piping used. 

 In choosing the boiler do not be misled into getting one 

 that is too small for its work. Allow a broad margin 

 beyond the maker's estimate of size necessary to heat a 

 given quantity of piping. A new boiler well fixed and 

 driven hard by constant attention may do all that is 

 claimed for it at first, but will not continue to do so for 

 long without more attention than one is prepared to 

 give it. In any case, the amount of necessary attention is 

 less with a fairly big boiler than it is with a small one. 



The Garden Frame. An indispensable companion to 

 the greenhouse is the portable garden frame. Under 

 good management it will never be empty for long to- 

 gether, and will act as a feeder to the greenhouse 

 proper, for in it can be raised and " grown on " plants 

 innumerable, which will in their turn help to embellish 

 the more pretentious structure. Its several uses will be 

 mentioned as I deal with the cultivation of plants in 

 other chapters, and this must serve as an apology for 

 so briefly dismissing it in this. 



