a soft rubber washer. The bushing
is shaped like a "T" with a hole drilled in the stem. The stem of the
bushing fits down into the post hole in the cover, the flange at the
top testing on the raised portion of the cover around the post hole.
The post has a shoulder a little less than halfway up from its lower
end. Upon this shoulder is placed the hard rubber washer, and upon the
hard rubber washer is placed the soft rubber washer. This assembly is
fastened to the cover by the "peening" process used in Prest-O-Lite
automobile batteries as described on page 386. This forces the soft
rubber washer tightly against the cover so as to make a leak proof
joint-between the bushing and cover. The ring of lead formed around
the posts by the peening process supports the posts, plates, and
separators, which therefore are suspended from the cell cover. The
plate straps extend horizontally across the tops of the plates, and
thus also act as "hold-downs" for the separators. The separators are
held up by two rectangular rubber bridges which fit Mito slotted
extension lugs cast into the lower corners of the outside negative
plates. An outside negative having these extension lugs is shown in
Figure 303.

[Fig. 301 Cover of Prest-O-Light farm lighting cell]

[Fig. 302 Parts of Prest-O-Light farm lighting cell: nut,
stud, terminal, hard rubber bushing]

[Fig. 303a Parts of Prest-O-Light farming light cell: glass
jar, rubber jar, rubber cell connector, glass cell connector]

[Fig. 303b Parts of Prest-O-Light farm lighting cell: positive
plate and outside negative plate]

[Fig. 303c Parts of Prest-O-Light farm lighting cell: long
lead jumper, jumper, separator, short lead jumper]

Specific Gravity of Electrolyte. The values of the specific gravity of
Prest-O-Lite farm lighting batteries are as follows:

Battery fully charged reads 1.250
Battery three-fourths charged reads 1.230
Battery one-half charged reads 1.215
Battery one-fourth charged reads 1.200
Battery discharged completely reads 1.180

These readings are to be taken with the electrolyte at a temperature
of 80 deg. Fahrenheit. Readings taken at other temperatures should be
converted to 80 deg.. To convert readings at a lower temperature to the
values they would have at 80 deg., subtract one point for every two and
one-half degrees temperature difference. For example, suppose a cell
reads 1.225 gravity at 60 deg.. To find what the gravity would be if t