468 On Managing Hot-house Fire-places. 



flue, and the height of the chimney. When a flue is once 

 properly heated, the draught becomes stronger, and then a 

 less opening in the register is sufficient to supply the tire with 

 air. Jn 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 will 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 chea- 

 per 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 unconsumed, must be pushed with an iron rake, towards 

 the further end of the bars, and fresh fuel applied immedi- 

 ately 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, pro- 

 tects 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, for this is often the cause of flues 

 bursting. When coals are thrown beyond the fire, after it 

 has burnt low, and the flue is hot, the heat of the brick- 

 work distils gas out of the coals, this gas gets into the flue, 

 and when the fuel over the fire becomes inflamed, if the 

 flame be drawn into the flue, it ignites the gas that has 

 been there generated, and causes an explosion ; this ought 

 to be particularly attended to, as an explosion of gas in 



