28 THE CULTURE OF THE GRAPE. 



HEATING APPARATUS FOR CIRCULATING WATER ON THE 

 LEVEL PRINCIPLE. 



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 he built and ar- 

 ranged in the same way as detailed in the preceding article ; 

 but, instead of covering the furnace with tile and brick, the 

 boiler may 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 rapid when the 

 boiler contains but a small quantity of water, provided the 

 pipes are always full, which they must be. But it is essential 

 for a rapid circulation that ample distance be allowed between 

 the pipes, which may be from four to six inches in diameter ; 

 the lower one should be arranged first, and supported and 

 kept in place on a perfect level, by brick or stone. Above 

 this, should be the upper and warmest one, properly levelled 

 and arranged. You may place the pipes on either side of the 

 furnace, but the side next the front of the house is usually the 

 one considered best ; I would recommend four to six inches for 

 the space between them. I have in my houses, at the extreme 

 end, a tank containing thirty gallons or more of water, to which 

 the pipes are attached, in the same manner as to the boiler ; 

 but this is not necessary, though preferable. The pipes may 

 connect at the end by an elbow, and they work equally well ; 

 but a tank at this place with a quantity of water, which be- 

 comes heated, is of service, as this is the coldest part of the 



