n.
This could be done simply by running a small third wire from the
switchboard to the house. Then, when the lights became dim from
excessive load, a turn of the handle would bring them back to the
proper voltage; and when they flared up and burned too bright, a turn
of the handle in the opposite direction would remedy matters. By this
simple arrangement, any member of the family could attend to voltage
regulation with a minimum of bother.

_Automatic Devices_

There are several automatic devices for voltage regulation at the
switchboard on the market. These consist usually of vibrator magnets
or solenoids, in which the strength of the current, varying with
different speeds, reacts in such a way as to regulate field
resistance. Such voltage regulators can be had for $40 or less, and
are thoroughly reliable.

* * * * *

To sum up the discussion of governors and voltage regulators: If you
can allow a liberal proportion of water-power, and avoid crowding
your dynamo, the chances are you will not need a governor for the
ordinary reaction turbine wheel. Start your plant, and let it run for
a few days or a few weeks without a governor, or regulator. Then if
you find the operation is unsatisfactory, decide for yourself which of
the above systems is best adapted for your conditions. Economy as well
as convenience will affect your decision. The plant which is most
nearly automatic is the best; but by taking a little trouble and
giving extra attention, a great many dollars may be saved in extras.

_Starting the Dynamo_

You are now ready to put your plant in operation. Your dynamo has been
mounted on a wooden foundation, and belted to the countershaft, by
means of an endless belt.

See that the oil cups are filled. Then throw off the main switch and
the field switch at the switchboard; open the water gate slowly, and
occasionally test the speed of the dynamo. When it comes up to rated
speed, say 1,500 per minute, let it run for a few minutes, to be sure
everything is all right.

Having assured yourself that the mechanical details are all right, now
look at the voltmeter. It is probably indicating a few volts pressure,
from 4 to 8 or 10 perhaps. This pressure is due to the residual
magnetism in the field cores, as the field coils are not yet
connected. If by any chance, the needle does not register, or is now
back of 0, try changing about the connections or the voltmeter on the
back o