Horse-Power of Water.—Indian Government rule, 15 cube feet per second falling through 1 foot = 1 HP.
Indicator Diagram.—The drawing produced by an instrument which is fixed to the cylinder of a steam-engine for the purpose of ascertaining its duty.
Induction.—The name given to effects produced out of a force-exerting body or out of the circuit to which the force is directly applied. A current in a wire induces currents in other conductors parallel to it.
Inertia.—The resistance to change of state of rest or motion.
Insulators.—Bodies possessing high electrical resistance. All insulating substances, however, allow some electricity to pass.
Intensity.—The old term for the properties now described as E. M. F. and potential.
Joule, also called Joulad (W).—The Unit of heat or work, it has also been applied to the mechanical equivalent of heat, 772 foot lbs.
Kilowatt.—One thousand watts.
Knot.—The geographical and nautical mile.
Leads.—Terms usually applied to copper conductors.