This pipe passes beneath the lagging until it reaches the smoke box, which is done to keep it warm and prevent the oil from freezing, while the steam pressure enables the oil to feed against the steam pressure in the steam chest.
The slide valve is balanced by means of strips let into its back, and bearing against a plate fixed to the steam chest cover.
The frame on the side of the engine shown in the engraving is shown broken away from the yoke a to the fire box, so as to expose the link motion to full view, the shaded portion of the frame being that on the other side of the engine.
The yoke or brace a carries one end of the guide bars. The safety valve s may be raised to see that it is in working order, or to regulate the steam pressure, by the lever o, which has a ratchet tongue engaging with the notches at l.
Fig. 3326a.
Fig. 3326b.