180 GARDENING FOR PLEASURE. 



when it left the furnace. This perfect draft also does 

 away with all danger of the escape of gas from the flues 

 into the greenhouse, which often happens when the 

 draft is not active. Although no system of heating by 

 smoke flues is so satisfactory as by hot water or steam, 

 yet there are many who do not want to go to the expense 

 of hot-water heating, and to such this revived method is 

 one that will, to a great extent, simplify and cheapen 

 the erection of greenhouses. 



Figure 62 (one-eighth of an inch to the foot scale) 

 shows a greenhouse twenty feet wide by fifty feet long, 

 with furnace room, or shed, ten by twenty feet. Here 



Fig. 63. (Scale l / 8 of an inch to the foot.) 



the flues are so disposed as to avoid crossing the walks, 

 being placed under the center bench, but as near as pos- 

 sible to the walk on each side, so that the heat may be 

 evenly diffused throughout. If a difference in tempera- 

 ture is required in a house of this kind, it may be ob- 

 tained by running a glass partition across the house, say 

 at twenty-five feet from the furnace end, which will, of 

 course, make the latter end the hottest. It will be ob- 

 served that the plan (figure 62) shows by dotted lines 

 this new or revived plan of flue heating. Figure 63 (the 



