FROM DIFFERENT Vl'I'AltA 1 I - I" 



and it" provision is made for supplying tin- burning body with 

 Intensely heated nir. any required quantity of coal may be con- 

 sumed, and the present manner of lining them with (hiek brick 

 maybe entirely dispensed with, by substituting either thin 

 tiles,' or a thin coating of clay lute, sufficient to preserve the 

 iron from fusion or oxidation, and as this would present less 

 obstruction to the speedy communication of the heal generated 

 to the air of the room, consequently less would escape into the 

 chimney. 



In examining the construction of the open parlour grate, \\< 

 do not find in it one entire quality possessed by the close stove ; 

 the only one which hears any approach to similarity. is that 

 three sides of the grate are lined with fire brick, hut as the 

 fourth is almost wholly exposed, its utility is thereby defeated. 



It is admitted that the combustion is very perfect and rapid, 

 when the sheet iron door, or "blower" as it is technical!.! 

 termed, is applied to close the front of the grate : and this must 

 be a necessary consequence, as its application transforms the 

 open grate into a powerful air furnace, by which the que. 

 for the admission of air is very much reduced, and the air ifl 

 also, probably, reduced in quantity, this not being compensated 

 by its increased velocity, and as the blower defends the body 

 of coal in front from the cold air. to which it was before expott d, 

 the required elevation in temperature is effected and main- 

 tained without difficult] . 



It is only by radiation that any heal is imparted to the room 

 from coal consumed in open grates, and as the radiated heal is 

 known to be very small limn the surface of that portion of 

 COal which i> exposed to the front or open part of the urate. 

 the amount of heat imparted to the room would not probabrj 

 be diminished, but rather increased, by using a thin plate I 

 cast iron tor the front of the grate, by which the difficult; "< 

 consuming small quantities of coal would be rery much dimi- 

 nished : and this would not he less agreeable in ij~ BJ |" ■■•r.me. 

 than the equally aombn aspect presented bj the u«ignited coal 

 in the front of the generality of small grates, and particularly 

 as the top of the coal would' be exposed to m w,and pre* nt 

 more luminous appearance 



VOL. III. N 



