4. Q. How is the lead affected by movement of the reverse lever with the
two gears?

A. With the Stephenson gear the lead increases as the reverse lever is
hooked toward the center in both forward and back motion. With the
Walschaert gear the lead is the same in all positions of the lever, so
that the lever is used to reverse the engine or adjust the cut-off.

5. Q. In reversing, how do the two gears differ as to the movement of
the link and link block?

A. With the Stephenson gear, when reversing, the link is raised and
lowered, bringing the block which is not moved by the reverse lever
under control of either the forward or back-up eccentric as is desired
to move the engine the proper way. With the Walschaert gear the link is
not moved by the reverse lever, but the link block is raised and lowered
in the link; the position of the block above or below the center of the
link controlling the direction of motion.

6. Q. What would you disconnect if the eccentric crank, eccentric rod,
or the arm at the bottom of the link should break?

A. Would remove the broken parts, disconnect the link lifter from the
radius rod and block the link block in the center of the link; the
combination lever would then move the valve twice the amount of its lap
and lead, which would be sufficient to provide for lubricating the
cylinder.

7. Q. If the main crank pin was broken?