300 On the Construction of Kite/ten 



but, although it effectually answers the purpose, yet it 

 is attended with a serious inconvenience, which, as it 

 is not very obvious, ought to be mentioned. When 

 the bottoms of roasters were made flat, their dripping- 

 pans were much more liable to be too much heated 

 than they are when, the body of the roaster being made 

 cylindrical, the dripping-pan is placed on a shelf in the 

 manner I have here recommended. And several persons, 

 finding the water in the dripping-pans of their roasters 

 to boil away very fast, covered the (flat) bottoms of their 

 roasters with sand, or with a paving of thin tiles or bricks. 

 This produced the desired effect; but this contriv- 

 ance occasions the bottom of a roaster to be very soon 

 burned out and destroyed. The heat from the fire com- 

 municated to the under side of the bottom of the roaster, 

 not being able to make its way upwards into the body of 

 the roaster through the stratum of sand or bricks (which 

 substances are non-conductors of heat), it is accumulated 

 in the bottom of the roaster, and becomes there so intense 

 as to destroy the iron in a short time. 



The best method that can be adopted for preventing 

 the dripping-pan from being too much heated is to de- 

 fend the bottom of the roaster from the direct action 

 of the fire by interposing a screen of some kind or other 

 between it and the burning fuel. This screen may be 

 a plate of cast iron, about one third of an inch thick, 

 with a number of small holes through it, supported upon 

 iron bars at the distance of about an inch below the 

 bottom of the roaster ; or it may be formed of a row of 

 thin flat tiles laid upon the blowpipes, and supported by 

 them. 



Roasters which are made of a cylindrical form will 

 hardly stand in need of any thing to screen them from 





