erminal in the elevator well necessarily alters
the space between the terminal pulley and the bottom of the well. This
is of little consequence in grain elevators, but for elevators intended
to handle coal or any material of varying size the ordinary tightening
gear is unsuitable. In such a case the best plan is to attach the
elevator-well to the terminal in such a way as to go up or down with the
sprocket wheel when the chain is loosened or tightened, while the foot
bracket which supports the well and terminal spindle remains a fixture.
In order to tighten elevator chains without interfering with either of
the terminals, adjustable jockey pulleys at some suitable point may be
used, and the desired effect can thus be attained by pressing against
the chains and thereby taking up the slack without any interference with
either the feed or delivery end.

Elevator buckets must be proportioned to the size and nature of the
material they are intended to carry, and care must be taken to
maintain a uniform feed. This may readily be effected by adjustable
outlets and spouts for grain and the like, and by certain feeding
devices for handling minerals of uneven size. For instance, an
oscillating feed shoot making from 30 to 60 oscillations per minute
can be installed in such a case, and adjusted to deposit at each
backward and forward stroke the exact amount of material adapted to
the capacity of the elevator. The speed of the shoot will naturally
vary with the size of material to be fed. For small coal 60
oscillations would be about the correct speed; for large coal the
speed might be reduced to 30 or less. Speaking generally, care should
always be taken to prevent an undue rush of feed, that is, more than
the elevator can take up, and if tenacious materials are handled,
feeding devices should be employed provided with stirrers or agitators
that will effectually keep the material moving and prevent any larger
lumps from arching over the feed spout, and thus producing chokes.
Elevators should always be fed from that side on which the buckets
ascend, that the stream of material may meet the elevator buckets on
their upward journey. This will prevent the material from filling up
the elevator well and spare the buckets from dredging through an
accumulation of feed. Elevators erected at an incline are best fed at
a point several feet above the well into the chain of ascending
buckets, as