The horse power of an engine as indicated by its steam pressure, length of stroke, and piston area, and vacuum, without making any deduction for friction or hurtful resistances. The steam pressure is in accurate work deduced from indicator diagrams.

The equivalent of a mechanical horse power in electric units, generally in volt-amperes or watts; 745.943 watts are equivalent to the activity of one British horse power; 735.75 are equivalent to one metric horse power. The number 746 is usually taken in practical calculations to give the equivalency. [Transcriber's note: Contemporary values are: Mechanical (British) [...]

The rate of activity of a machine, as actually developed in condition for use. It is less than the indicated or total horse power, because diminished by the hurtful resistances of friction, and other sources of waste. It is the horse power that can be used in practise, and which in the case of a [...]

A unit of rate of work or activity. There are two horse powers. The British horse power is equal to 33,000 pounds raised one foot per minute, or 550 foot pounds per second, or 1.0138 metric horse power. The metric horse power (French) is equal to 75 kilogram-meters, or 542 foot pounds per second, or [...]

The extensions of the pole pieces of a dynamo or motor. (See Following Horns-Leading Horns.) Synonym–Pole Tips.

A tin hood placed over an arc-lamp. Such hoods are often truncated cones in shape, with the small end upwards. They reflect a certain amount of light besides protecting the lamp to some extent from rain.

(a) The adjustable clamps for holding the armature brushes of dynamos and motors. (b) The clamps for holding the carbons of arc lamps. (c) The clamps for holding safety fuses, q. v. (d) Holders for Jablochkoff candles and other electric candles. (See Candle Holders.) (e) A box or block of porcelain for holding safety fuses.

A solution used as a resistance. It is a solution of cadmium iodide in amylic alcohol. Ten per cent. of the salt is used. It is contained in a tube with metallic cadmium electrodes. (See Resistance, Hittorf’ s.)

A term applied to a noise sometimes produced by a voltaic arc; probably due to the same cause as frying, q. v.

A term used as a noun or as an adjective to indicate in an alternating current, the production of a very great number of alternations per unit of time–usually expressed as alternations per second.