154 COMMERCIAL ROSE CULTURE 



three inches of water above the top of the upper row of tubes. 

 If a tube should split, or become pitted so that it leaks, a dry 

 Pine plug may be driven into either end, when it may be run 

 for a day or two until a new tube can be put in. 



Wetting down ashes and clinkers close to the boiler front 

 will cause corrosion of the boiler metal and do harm. Coal 

 which contains much sulphur will form an acid and corrode 

 the plates. Any cracks in the brick setting of a boiler should be 

 pointed up as they admit air, chilling the boiler and cooling off 

 the gases. 



To prevent the gaskets from sticking to the hand and man- 

 hole plates coat them on both sides with graphite or plumbago 

 and oil. A good putty for joints is made by mixing white 

 lead ground in oil with dry red lead into which a little asbestos 

 may be worked if it is to be used near the fire. 



g<r- - i '.' '""" *-j- "' "- 



THE ART OF FIRING 



When firing, feed with coal little and often; keep a level 

 fire about six inches thick; a fire too heavy is wasteful, for the 

 air is not so well able to get through the grate. Avoid holes in 

 the fire and keep it clean so that it looks bright the whole 

 distance in the ash pit with the heaviest fire toward the back. 



If too hot a fire is carried at the front there is the liability 

 of burning the furnace doors and, also, if the brickwork over 

 the arches is not in good repair there is the danger of burning 

 out the dry sheet which is the sheet outside the part contain- 

 ing the water. Some types of boilers do not have this over- 

 hanging dry sheet. 



Burn the fires down as low as possible in the morning ; clean 

 them and push the fire back up to the bridge wall, then bank it 

 with fine coal and keep all the doors shut. If any gas is noticed 

 the damper in the chimney may be opened slightly. Some fire- 

 men leave the furnace doors open all day; this wastes the heat 

 and does harm to the boiler plates by admitting so much cold air, 



