24 PL/fNT PHYSIOLOGY. 



of heating by stoves which any builder of greenhouses can give 

 advice about. As to cost, it is impossible to give any exact 

 estimate, since this depends upon size, permanency, and many 

 other considerations. Small houses, such as are furnished for 

 amateur horticulturists, may be bought for from three hundred 

 dollars upwards ; while such a greenhouse as is described later 

 in this chapter, built for the utmost convenience, completeness, 

 and permanency, if heat is available from a neighboring build- 

 ing will cost at least fifteen hundred dollars, while the labora- 

 tory described will cost about twelve hundred dollars complete. 

 If nothing else is available, it may be possible to hire a portion 

 of a commercial greenhouse in the vicinity. But economical, 

 accurate, profitable physiological work cannot be done without 

 a good greenhouse. 



Such advice as I can offer upon the building and equipment 

 of a physiological greenhouse and laboratory may be given in 

 the form of a description of the plans for proposed new houses 

 for Smith College, which embody the best I have been able to 

 develop from my own experience. Sketches of the plans will 

 be found in Figs. 2 to 6. The shape of the houses there given 

 is necessitated by the nature of the ground and the position in 

 which they must adjoin the present range of greenhouses ; 

 probably were this condition not present it would be better to 

 make them both more nearly square. 



These houses are planned for a class of twelve students, 

 together with three or four students working upon special 

 topics. The greenhouse (Fig. 2) is 32 by 18 feet inside 

 measurement, with brick walls a foot thick rising above the 

 floor 3 feet 6 inches, above which is glass to a height of 6 feet, 

 while the center of the roof rises to 12 feet. Ample ventilators 

 are needful both on sides and roof. The floor is everywhere 

 cemented except where the pits for the heating-pipes occur. 

 These pipes must either be sunken under the floor and covered 

 with iron gratings, or else suspended along the walls in a single 

 vertical row ; for if placed above the floor in the usual way they 

 will render impossible the separate tables which are so essen- 



