ngs should be taken hourly of the specific
gravity and temperature of the electrolyte, voltage of the cells, and
amperage of charging current. A record or log should be kept of the
specific gravity and voltage of each of the cells of the battery
regularly during the life of the battery and it is well to commence this
record with the initial charge.

The initial charge should be maintained for at least ten hours after the
time when the voltage and specific gravity have reached a maximum. If
for any reason it is impractical to continue the initial charge
uninterrupted, the first period of charging should be at least from
twelve to fifteen hours. However, every effort should be made to have
the initial charge continuous, as an interruption tends to increase the
time necessary for the initial charge, and if the time be too long
between the periods of the initial charge, the efficiency and capacity
of the cells are liable to be affected. In case of a large battery,
precaution should be taken to insure that the ventilation is
exceptionally good, because if it is not good the temperature is liable
to increase considerably and thereby cause an undue amount of
evaporation from the cells.

The object of the temperature readings taken during the charge is to
enable corrections to be made to the specific gravity readings as
obtained by the hydrometer, in order that the correct specific gravity
may be ascertained. This correction is made by adding .001 specific
gravity for each three degrees in temperature above 70 deg. Fahrenheit,
or subtracting the same amount for each three degrees below 70 deg.
Fahrenheit. At the time the cells begin to gas they should be gone over
carefully to see that they gas evenly, and also to detect and remedy
early in the charging period any defects which may exist. If there is
any doubt in regard to the time at which the cells reach a maximum
voltage and specific gravity, the charge should be continued
sufficiently long before the last ten hours of the charge are commenced
to eliminate any such doubt, as in many cases poor efficiency and low
capacity of a cell later in its life may be traced to an insufficient
initial charge.

_Operation._ After the battery has been put in commission the periodic
charges should be carefully watched, as excessive charging causes
disintegration and decreases the life and capacity of the battery;
while, on the other hand, undercharging will result in sulphating of the
p