58 



GREENHOUSES 



jection only when the houses are long and 

 narrow. 



The above remarks refer only to separate 

 and connected houses of similar sizes. At 

 the present time there is a difference of opin- 

 ion as to the advantages of the single wide 

 and high house over the small and lower 



Fig. 30. Diagram showing that the same amount of 

 roof is required for several small, connected houses 

 as for one large house covering the same area if the 

 pitch is the same. a+b+c+d+e+f=A+B. 



houses connected in the ridge-and-furrow 

 system. Contrary to the prevailing notion, 

 the same amount of glass is required by each 

 system if the roofs are of the same slant or 

 pitch. 



The following advantages are claimed for 

 the large, single houses: (i) They are more 

 easily kept at an even temperature, (2) venti- 

 lation may be secured without subjecting the 



