18 



THE GRAPE. 



Fig. 14. 



iiig the lower part, or front, cold ; wliich, if there he a dif- 

 ference, ought to he the warmest. The only way in which 

 this plan can be tolerated, or he of 

 advantage, is, to combine the cham 

 her and fine, and make use of both. 

 This is economizing, as the whole 

 of the heat which radiates from both 

 sources is made available. Figs. 13 



and 14 show a longitudinal and 

 transverse cross section of both com- 

 bined. 



In concluding, we may say, that 

 after many years' practice with most 

 kinds of heating apparatus for hot-houses, we are thor- 

 oughly convinced that none is so efficient or economical 

 as hot water, and have never found any on that principle 

 to superQcde the boiler, as exhibited in Fig. 12. 



