2 x 45/66,373 (No.
2) = 9 volts, nearly, less than 10 per cent. This is a very efficient
line, under the circumstances. Now if he is willing to lose 10 per
cent on _half-load_, instead of full load, he can save still more
money in line wire. In that case (as you can find by applying the
formula again), he could use No. 5 wire, at a cost of $28.50. He would
lose 11 volts pressure drawing 26 amperes; and he would lose 18 volts
pressure drawing 45 amperes, if by any chance he wished to use full
load.

In actual practice, this dynamo would be regulated, by means of the
field resistance, to register 110 plus 11 volts, or 121 volts at the
switchboard to make up for the loss at half-load. At full load, his
voltage at the end of the line would be 121 minus 18, or 103 volts;
his motor would run a shade slower, at this voltage, and his lights
would be slightly dimmer. He would probably not notice the difference.
If he did, he could walk over to his generating station, and raise
the voltage a further 7 volts by turning the rheostat handle another
notch.

[Illustration: A barn-yard light]

Thousands of plants can be located within 100 feet of the house. If
Farmer Jones could do this, he could use No. 8 wire, costing $2.62.
The drop in pressure would be 5.99 volts at full load--so small it
could be ignored entirely. In this case the voltmeter should be made
to read 116 volts at the switchboard, by means of the rheostat.

If, on the other hand, this plant were 1,000 feet away from the house
and the loss 10 volts the size wire would be

1,000 x 22 x 45
--------------- = 99,000 circular mills;
10

a No. 0 wire comes nearest to this figure, and its cost, for 2,000
feet, at 19 cents a pound, would be $137.94. A No. 0000 wire, costing
$294.00, would give a 5 per cent drop at full load. In this case, the
cost of transmission can be reduced to a much lower figure, by
allowing a bigger drop at half-load, with regulation at the
switchboard. Thus, a No. 2 wire here, costing but $95, would be
satisfactory in every way. The loss at half-load would be about 9
volts, and the rheostat would be set permanently for 119 or 120 volts.
A modern dynamo can be regulated in voltage by over 25 per cent in
either direction, without harm, if care is taken not to overload it.

_Benefit of Higher Voltages_

If Farmer Jones' plant is a half of a mile away from the house, he
faces a more serious proposition in the way of transmission. S