Using electrometer....... = almost infinitely small
currents.
Using delicate galvanometer =0.00,000,000,040 weber.
Current received from Atlantic
cable, when 25 words per minute
are being sent ................ = 0.000,001 weber
Current in ordinary land telegraph
lines ......................... = 0.003 weber
Current from dynamo machine.... = 5 to 100 weber

In any circuit, _current_ in webers = _electro-motive force_ in volts /
_resistance_ in ohms.


RATE OF PRODUCTION OF HEAT, CALCULATED IN THE SHAPE OF HORSE-POWER.

In the whole of a circuit=_current_ in webers x _electro-motive force_
in volts / 746. In any part of circuit=_current_ in webers x _difference
of potential_ at the two ends of the part of the circuit in question /
746. Or, =square of current in webers x resistance of the part in ohms /
746.

If there are a number of generators of electricity in a circuit, whose
electromotive forces in volts are E_1, E_2, etc., and if there are also
opposing electro-motive forces. F_1, F_2, etc., volts, and if C is the
current in webers, R the whole resistance of the current in ohms, P
the total horse-power taken at the generators, Q the total horse-power
converted into some other form of energy, and given out at the places
where there are opposing electro-motive forces, H the total horse-power
wasted in heat, because of resistance, then: