Ice weighs 56½ pounds per cubic foot.
Engineers can judge of the condition of their machinery by the tone it gives out while running. Every make of engine has a peculiar tone of its own. The engineer becomes accustomed to that, and any departure from it at once excites a suspicion that all is not right. The engineer may not know what is the matter, he may have no ear for music, but the change in tone of his machine will be instantly perceptible and will start him upon an immediate investigation.
An Indicator is an instrument used to determine the indicated horse-power of an engine; it shows the action of the steam in the cylinder and serves as a guide in setting valves to get the greatest amount of energy from the steam used.
Atmospheric pressure is the weight of the air.
To take lime from injector tubes, mix one part muriatic acid and ten parts soft water. Immerse tube in this mixture over night.
Compound for Cooling Heavy Bearings.—For cooling heavy pillow block bearings, or the steps of upright shafts, the following will be found very valuable: Four pounds of tallow, one-half pound of sugar of lead, three-fourths pound plumbago. When the tallow is melted (not boiling) add sugar of lead and let it dissolve; then put in the plumbago, and stir the whole mass until cold.
A mixture of soft soap and black lead makes an excellent lubricant for gears, as it lessens the abrasion and noise and has the advantage over tallow of not becoming hard. It is also easily removed should it become necessary to clean the parts on which it has been used.
The axles and axle arms of a traction engine should be well greased or oiled before moving, to prevent them from being cut and wearing both hub and axle rapidly.