urst?
A. (I) Never go beyond a safe working pressure. (2) Keep
the boiler clean and in good repair. (3) Keep the safety valves
in good shape and the water at its proper height.

Q. What is the first thing to do on going to your engine in
the morning?
A. See that the water is at its proper level.

Q. What is the proper level?
A. Up to the second gauge.

Q. When should you test or try the pop valve?
A. As soon as there is a sufficient pressure.

Q. How would you start your engine after it had been
standing over night?
A. Slowly.

Q. Why?
A. In order to allow the cylinder to become hot, and that the
water or condensed steam may escape without injury to the
cylinder.

Q. What is the last thing to do at night?
A. See that there is plenty of water in boiler, and if the
weather is cold drain all pipes.

Q. What care should be taken of the fusable plug?
A. Keep it scraped clean, and not allow it to become
corroded on top.

Q. What is a fusible plug?
A. It is a hollow cast plug screwed into the crown sheet or
top of fire box, and having the hollow or center filled with lead
or babbit.

Q. Is such a plug a protection to a boiler?
A. It is if kept in proper condition.

Q. Can you explain the principle of the fusible or soft plug
as it is sometimes called?
A. It is placed directly over the fire, and should the water
fall below the crown sheet the lead fuses or melts and allows
the steam to flow down on top of the fire, destroys the heat and
prevents the burning of crown sheet.

Q. Why don't the lead fuse with water over it?
A. Because the water absorbs the heat and prevents it
reaching the fusing point.

Q. What is the fusing point of lead?
A. 618 degrees.

Q. Is there any objection to the soft plug?
A. There is, in the hands of some engineers.

Q. Why?
A. It relieves him of the fear of a dry crown sheet, and gives
him an apparent excuse for low water.

Q. Is this a real or legitimate objection?
A. It is not.

Q. What are the two distinct classes of boilers?
A. The externally and internally fired boilers.

Q. Which is the most economical?
A. The internally fired boiler.

Q. Why?
A. Because the fuel is all consumed in close contact with the
sides of furnace and the loss from radiation is less than in the
externally fired.

Q. To what class does the farm or traction engine belong?
A. To the internally fired.

Q. How would you find the H.P. of such a boil