ve them a considerable amount of lead. As to the second requirement,
the maintenance of initial pressure until cut off, giving a straight
steam line, cards from this engine will not be found to show that the
engine satisfies this requirement, and for this reason, that the
cut-off valve commences to close the port immediately after the piston
commences to move. The cut off eccentric you will remember is set to
move with the crank or very nearly so, and the lighter the load, the
greater will this fact appear. For the lightest loads the governor
places the eccentric in advance of the crank, so that the cut off
valve will commence to close the port before steam is admitted by the
main valve to the engine. Now, the later the cut off, the less will
this wire drawing appear at first, and the shorter the cut off, the
amount of wire drawing increases sensibly. The operation of the valve,
therefore, in this particular, cannot be considered as meeting our
requirement that the port shall be held open full width until ready to
be closed. Many men claim for this engine that the closing occurs when
the cut off eccentric is moving its fastest. This is a fact, and if we
consider the point of cut off only to be the point of absolute cut
off, the cut off must be instantaneous, for there is an instantaneous
point where the cut off is final only to be considered. The reasoning
applied here would hold good also to a less extent on the slide valve,
but is not the point of absolute cut off. We want to note how long it
is from the time the valve commences to close at all until finally
closed, and, as I have shown you, this is considerable in this engine.

Referring to the point of cut off finally, it is determined upon by a
governor of the fly wheel type. The eccentric is loose about the
shaft, and arms projecting therefrom are connected by other arms to
the extremity of an arm upon which is mounted a weight, and which is
attached to the spokes of the fly wheel, or special governor wheel in
this case, and which is fastened to the crank shaft. As the speed
increases through throwing off a portion of the load the governor
weights fly out, and this movement is transferred through the lever
connections to the eccentric, causing it to be turned ahead, and the
manner hastening the movement of the cut off valve on its seat and
causing it to reach and cover the edge of the steam port earlier in
the stroke. This engine was the pioneer in governors of thi