he dynamo, a direct-current machine, 110 volts pressure, and what is
known in the trade as "compound,"--that is, a machine that maintains a
constant pressure automatically and does not require an attendant--was
picked up second-hand, through a newspaper "ad" and cost $90. The
switchboard, a make-shift affair, not very handsome, but just as
serviceable as if it were made of marble, cost less than $25 all told.
The transmission wire cost $19 a hundred pounds; it is of copper, and
covered with weatherproofed tape. Perkins bought a 50-cent book on
house-wiring, and did the wiring himself, the way the book told him
to, a simple operation. For fixtures, as we have said, his wife
devised fancy shades out of Mexican baskets, tissue paper, and silk,
in which are hidden electric globes that glow like fire-flies at the
pressing of a button. The lamps themselves are mostly old-style carbon
lamps, which can be bought at 16 cents each retail. In his living room
and dining room he used the new-style tungsten lamps instead of
old-style carbon. These cost 30 cents each. Incandescent lamps are
rated for 1,000 hours useful life. The advantage of tungsten lights is
that they give three times as much light for the same expenditure of
current as carbon lights. This is a big advantage in the city, where
current is costly; but it is not so much of an advantage in the
country where a farmer has plenty of water-power--because his current
costs him practically nothing, and he can afford to be wasteful of it
to save money in lamps. Another advantage he has over his city cousin:
In town, an incandescent lamp is thrown away after it has been used
1,000 hours because after that it gives only 80% of the light it did
when new--quite an item when one is paying for current. The experience
of Perkins and his neighbor in their cooperative plant has been that
they have excess light anyway, and if a few bulbs fall off a fifth in
efficiency, it is not noticeable. As a matter of fact most of their
bulbs have been in use without replacing for the two years the plant
has been in operation. The lamps are on the wall or the ceiling, out
of the way, not liable to be broken; so the actual expense in
replacing lamps is less than for lamp chimneys in the old days.

Insurance companies recognize that a large percentage of farm fires
comes from the use of kerosene; for this reason, they are willing to
make special rates for farm homes lighted by electricity. They
prescr