sing from the liquid being deposited.
upon a high part set upon the funnel, and which, in their revolution, the
hanging wires touch. By this plan, however, the oil is not well supplied at
slow speeds, as the drops fall before the wires are in proper position for
feeding the journal. Another lubricator consists of a cock or plug inserted
in the neck of the oil cup, and set in revolution by a pendulum and ratchet
wheel, or any other means. There is a small cavity in one side of the plug,
which is filled with oil when that side is uppermost, and delivers the oil
through the bottom pipe when it comes opposite to it.

743. _Q._--What are the prevailing causes of the heating of bearings?

_A._--Bad fitting, deficient surface, and too tight screwing down.
Sometimes the oil hole will choke, or the syphon wick for conducting the
oil from the oil cup into the central pipe leading to the bearing will
become clogged with mucilage from the oil. In some cases bearings heat from
the existence of a cruciform groove on the top brass for the distribution
of the oil, the effect of which is to leave the top of the bearings dry. In
the case of revolving journals the plan for cutting a cruciform channel for
the distribution of the oil does not do much damage; but in other cases, as
in beam journals, for instance, it is most injurious, and the brasses
cannot wear well wherever the plan is pursued. The right way is to make a
horizontal groove along the brass where it meets the upper surface of the
bearing, so that the oil may be all deposited on the highest point of the
journal, leaving the force of gravity to send it downward. This channel
should, of course, stop short a small distance from each flange of the
brass, otherwise the oil would run out at the ends.

744. _Q._--If a bearing heats, what is to be done?

_A._--The first thing is to relax the screws, slow or stop the engine, and
cool the bearing with water, and if it is very hot, then hot water may be
first employed to cool it, and then cold. Oil with sulphur intermingled is
then to be administered, and as the parts cool down, the screws may be
again cautiously tightened, so as to take any jump off the engine from the
bearing being too slack. The bearings of direct acting screw engines
require constant watching, as, if there be any disposition to heat
manifested by them, they will probably heat with great rapidity from the
high velocity at which the engines work. Every bearing of a di