38 THE CULTURE OF THE GRAPE. 



The fluGj for the first twelve feet after leaving the fur- 

 nace, should be built on two or three courses of brick, 

 (or a stone foundation may be substituted,) from thenco 

 to the chimney either on plank, (which is preferable on 

 account of drvness,) or on bricks laid one or two inches 

 apart ; one course of brick is sufficient for the floor of 

 the flue. I usually have the first few feet of the sides of 

 the flue built with the bricks laid flat, and, after this, on 

 their sides, as represented in the lean-to house. 



KEATING APPAEATUS FOE CIECULATING WATEE ON THE 

 LEVEL PKINCIPLE. 



When the house is to be heated with hot water, (which 

 I prefer when a great and steady heat is required through 

 the whole winter,) the furnace and flue should be built 

 and arranged in the same way as detailed in the preced- 

 ing article ; but, instead of covering the furnace with 

 tile and brick, the boiler will be used. This may be of 

 cast iron, or of sheet copper, and of proper size for the 

 furnace. It is necessary to have fifteen or eighteen 

 inches depth to this, that ample space may be allowed 

 for the pipes, one above the other, on the side. The 

 lower one should enter as near the bottom as possible, 

 and the upper one as near the top. The principle upon 

 which the water acts is this, that hot water is lighter 

 than cold ; consequently, when this becomes heated by 

 the fire, it rises to the top and thence to the pipe ; the 

 cold water in the lower pipe comes in to fill the space of 

 that heated, and the circulation commences, and is more 



