48 THE GEAPE CULTtJKIST. 



the more it rises, the more rapidly the smoke and heat wiD 

 pass. The size of the furnace will depend upon the size 

 of the house, and also whether coal or wood is used. 



TO MAKE THE FLUES. 



Lay a row of bricks flat and crosswise, where the flue is 

 desired ; on the ends of these place two others on their 

 edges, and across the top lay a row flat in the same 

 way as the bottom ones were placed. This gives the 

 dimensions of the flue four inches by eight in the clear. 

 But a larger flue is better, say six by eight inches, for a 

 house of fifty or more feet in length, and it is also better 

 to cover the top of the flues with the ordinary inch tile, as 

 the heat passes through these more readily than through 

 brick. No correct estimate of the cost of building a prop- 

 agating house, of either of the styles named, can be given, 

 because the price of the material? entering into their con- 

 struction is continually changing 



There has been lately a round tile introduced, which is 

 sometimes used for the flues in propagating houses. It is 

 made of common brick material, and about six inches in 

 diameter and three feet long. When fitted together, and 

 a little mortar used at the joints, a very cheap and neat- 

 looking flue is made with it, and there is little danger 

 from escaping gas. The thickness of the tile flues is much 

 less than those of brick, and they do not retain heat so long, 

 consequently the fire will requii-e more frequent attentioa 



