valves for inside admission, and, on the other hand, for outside
admission?

A. If the piston is in the front end of the cylinder, an inside
admission valve must move forward in order to connect the inside of the
valve with the front live steam port to admit steam against the piston.
The outside end of the valve opens the exhaust port for the back end of
the cylinder. In the same position of the piston an outside admission
valve must move backwards to open the steam port or in the same
direction as the steam piston when commencing its stroke.

30. Q. What is an Allen ported valve, and what is its object?

A. An Allen ported valve is an outside admission slide valve having an
extra port from one end of the valve to the other, above the exhaust
cavity and through the body of the valve. This extra port is calculated
to admit steam through the valve at the same time that steam passes by
the end of the valve into the same steam port, thus doubling the area of
opening for live steam when the port is first opened.

31. Q. What is the difference in the valve motion for outside admission
valves and for inside admission valves?

A. An outside admission valve must be moved in the opposite direction to
an inside admission valve in relation to the movement of the steam
piston when beginning its stroke; therefore either the position of the
eccentric or the position of the rocker arms in relation to the rocker
shaft must be opposite for a change in these valves.

32. Q. What is a direct motion valve gear? What is an indirect motion