d of flowing out in quantities against
flash walls before it has time to ignite.

37. Q. What is the real object of having the fire-box lined with bricks,
and will engine steam without them?

A. Not so well as with the brick, the sheets being in contact with water
are too cool to flash the oil readily and hence the use of what is
called a "flash wall" built of fire brick and heated to a very high
temperature aids combustion very materially.

38. Q. Do you consider it your duty to keep close inspection of brick
work as to need of repairs, such as air entering between brick and side
sheets?

A. Yes. To see that plaster is kept between the walls and sheets to keep
cold air from being drawn in.

39. Q. Will engine steam if brick falls in front of burners or in path
of flame and what may be done?

A. No. Remove them with the brick hook or rod by pulling them out
through damper of draft pan.

40. Q. Where engine is equipped with an oil-reheater or oil line, do you
consider it a help to engine's steaming qualities when used?

A. Yes; at all times this heater should be used.

41. Q. Why use second heater? Why not heat it to a high temperature in
oil tank with oil heater?

A. Too much gas generating and boiling the oil continually destroys the
higher qualities besides being hard to control the flow through
regulation valve.

42. Q. Do you consider a vent hole in oil tank advisable, and why?

A. Yes; to allow any accumulation of gas to escape and to admit the air
so that oil will flow freely.

43. Q. Do you inspect your oil pipes and report all leaks? What other
bad effect has a pipe leak aside from waste of oil?

A. Yes. It will cause oil to feed irregularly.

44. Q. Are you aware that keeping the flues clean is the greatest one
thing that you can do in regard to fuel economy, and how often should
they be cleaned?

A. Yes. At least every ten miles.

45. Q. Do you know that the engine should be working hard and at a speed
not less than twenty miles per hour when sanding flues to avoid the sand
falling to floor of the fire-box and accumulating in front of them?

A. Yes.

46. Q. Do you realize that on first closing throttle you should not
adjust fire too low? Explain best method.

A. Yes. I would allow steam pressure to fall back some fifteen pounds
before throttle is closed and on having closed same leave a good fire in
box, allowing it to cool gradually to avoid leaky flues, broken
staybolts, cracked sh