48 



FURNACES. 



and printed for private distribution by that gentleman, and afterwards 

 published in the Hurt. Trans. The directions are so valuable, that vre 

 will give the contents of that paper at length. 



Wlien the fire is first lighted, the ash pit door may be left open imtil 

 the fuel be properly kindled ; the door should then be shut close, lea^^ng 

 the brass register so far open as to allow sufficient air to blow the fire, but 

 not more than is absolutely necessary to make it burn well, not \'iolently, 

 nor with a strong draught, for if more air be admitted than is required for 

 a moderate brisk fire, it occasions a great waste of fuel, without increasing 

 the heat. 



" The fire place door must at all times be kept shut, and the sloping 

 part of the iron frame of the door must be kept clear of coals, so as not 

 to prevent the door from latching. No air must be let in at the door at 

 any time, except when it cannot be avoided in feeding the fire. Any cold 

 air that may get in at the fire place door is apt to rush over the fire into 

 the flue vdthout being heated, and that air tends to cool the flue, instead 

 pf heating it. Therefore, all the air that is necessary for blowing the fire 

 must be admitted at the ash pit register, in order that it may get heated in 

 passing through the fire to the flue. 



" It is impossible to determine the exact opening necessary to be left in 

 the ash pit register to admit sufficient air, as that greatly depends upon the 

 goodness and length of the flue, and the height of the chimney, ^^llen a 

 flue is once properly heated, the draught becomes stronger, and then a less 

 opening in the register is sufficient to supply the fire vdth air. In this 

 state about half an inch opening in the register is generally sufficient, and 

 it should be shut quite close if it be found that the fire ^vill burn with it 

 in that position, as a considerable quantity of air will get in through the 

 joints of the ash pit door. 



" The best fuel for hot house fire places is about equal quantities of 

 coal and small cinders, or braise. This is cheaper than using coals only, 

 and keeps up a steadier fire with less smoke. 



" At all times when fresh fuel is added to the fire, the hot fuel uncon- 

 sumed must be pushed with an iron rake towards the further end of the 

 bars, and fresh fuel appUed immediately in the front of it, so as to fill up 

 the space between the. bars and the inner part of the frame of the double 

 door. 



" This fuel being dead between the bars and the door, protects the door 

 from the heat of the fire, and prevents the iron from warping. 



" In supplying the fire with fresh fuel, great care must be taken not to 

 throw it over to the further end of the fire, or into the throat of the flue, 



