6 ampere hours to 4,000 ampere hours,
respectively, when used at an average 8-hour discharge rate. In Fig. 416
is illustrated a storage cell employing a glass container and having
fifteen plates. Each plate is 11 inches high and 10-1/2 inches wide,
with an area, therefore, of 115.5 square inches. Such a cell has a
normal capacity of 560 ampere hours. The type illustrated is one made by
the Electric Storage Battery Company of Philadelphia, Pa.[A]

[Illustration: Fig. 416. Storage Cell]

_Installation._ In installing the glass jars it is customary to place
them in trays partially filled with sand. They are, however, at times
installed on insulators so designed as to prevent moisture from causing
leakage between the cells. The cells using wooden tanks are placed on
glass or porcelain insulators, and the tanks are placed with enough
clearance between them to prevent the lead lining of adjacent tanks from
being in contact and thereby short-circuiting the cells. After the
positive and the negative plates have been installed in the tanks, their
respective terminals are connected to bus bars, these bus bars being,
for the small types of battery, lead-covered clamping bolts, while in
the larger types reinforced lead bus bars are employed, to which the
plates are securely joined by a process called lead burning. This
process consists in melting a portion of the bus bar and the terminal
lug of the plate by a flame of very high temperature, thus fusing each
individual plate to the proper bus bar. The plates of adjacent cells are
connected to the same bus bar, thus eliminating the necessity of any
other connection between the cells.

_Initial Charge._ As soon as the plates have been installed in the tanks
and welded to the bus bars, the cell should be filled with electrolyte
having a specific gravity of 1.180 to 1.190 to one-half inch above the
tops of the plates and then the charge should be immediately started at
about the normal rate. In the case of a battery consisting of cells of
large capacity, it is customary to place the electrolyte in the cells as
nearly simultaneously as possible rather than to completely fill the
cells in consecutive order. When the electrolyte is placed in the cells
simultaneously, the charge is started at a very much reduced rate before
the cells are completely filled, the rate being increased as the cells
are filled, the normal rate of charge being reached when the cells are
completely filled. Readi