Of Food. 423 



any given quantity of water already boiling hot as 

 would be necessary to heat the same quantity of ice- 

 cold water to the boiling point will see the enormous 

 waste of heat, and consequently of fuel, which in all 

 cases must result from violent boiling in "culinary 

 processes. 



To prevent the soup from burning to the boiler, the 

 bottom of the boiler should be made double, the false 

 bottom (which may be very thin) being fixed on the 

 inside of the boiler, the two sheets of copper being 

 everywhere in contact with each other ; but they 

 ought not to be attached to each other with solder, 

 except only at the edge of the false bottom where it is 

 joined to the sides of the boiler. The false bottom 

 should have a rim about an inch and a half wide, pro- 

 jecting upwards, by which it should be riveted to the 

 sides of the boiler; but only few rivets, or nails, should 

 be used for fixing the two bottoms together below, 

 and those used should be very small ; otherwise, where 

 large nails are employed at the bottom of the boiler, 

 where the fire is most intense, the soup will be apt to 

 burn to, at least on the heads of those large nails. 



The two sheets of metal may be made to touch each 

 other everywhere by hammering them together after 

 the false bottom is fixed in its place ; and they may be 

 tacked together by a few small rivets placed here and 

 there at considerable distances from each other, and 

 after this is done the boiler may be tinned. 



In tinning the boiler, if proper care be taken, the 

 edge of the false bottom may be soldered by the tin to 

 the sides of the boiler; and this will prevent the water, 

 or other liquids put into the boiler, from getting be- 

 tween the two bottoms. 



