d thing to be generous and
accommodating, but every battery repairman should think of his own
business first, before he helps build up the business of a competitor.

The customer must have some inducement to bring in your rental battery
and get his own. A rental charge of 25 cents-per day serves as a
reminder to most customers. However, some customers are forgetful and
the battery man must telephone or write to any owner who fails to call
for his battery. If, due to failure to keep after the owner, a rental
battery is out for several weeks, there is likely to be an argument
when the rental bill is presented to the owner. If the delay in
calling in a rental battery is due to failure to repair the customer's
battery, the rental charge should be reduced.

A rental battery should not be put in place of a battery which is
almost ready for the junk pile. The thing to do is to sell the
customer a new battery. Repairs on an almost worn out battery are
expensive and the results may not be satisfactory.

RADIO BATTERIES

The wide-awake battery man will not overlook the new and rapidly
growing field which has been opened for him by the installation of
hundreds of thousands of radio-phone receiving sets in all parts of
the country. The so-called radio "craze" has affected every state, and
every battery repairman can increase his income to a considerable
extent by selling, charging, and repairing radio storage batteries.

The remarkable growth of the radio-phone has, of course, been due to
the radio broadcasting stations which have been established in all
parts of the country, and from which concerts, speeches, market
reports, baseball reports, news reports, children's stories and
religious services are sent out. These broadcasting stations have
sending ranges as high as 1,000 miles. The fact that a service station
is not located near a broadcasting station is therefore no reason why
it should not have its share of the radio battery business, because
the broadcasting stations are scattered all over the United States,
and receiving sets may be made powerful enough to "pick up" the waves
from at least one of the broadcasting stations.

Radio receiving sets may be divided into two general classes, the
"Crystal" sets and the "Bulb" sets. "Crystal" sets use crystals of
galena (lead sulphide), silicon (a crystalline form of silicon, one of
the chemical elements), or carborundum (carbide of silicon) to
"detect" or, in other word