to reach him. As soon as such facts
are known, they can be laid before the subscriber so that he may arrange
for additional incoming lines. In automatic practice this is not so
simple, as the source and destination of traffic in general is not so
clearly known to the traffic department. Automatic recorders of busy
calls are necessary to enable the facts to be tabulated.

CHAPTER XXXVIII

MEASURED SERVICE

In the commercial relation between the public and a telephone system,
the commodity which is produced by the latter and consumed by the former
is telephone service. Users often consider that payment is made for
rental of telephone apparatus and to some persons the payment per month
seems large for the rental of a mere telephone which could be bought
outright for a few dollars.

The telephone instrument is but a small part of the physical property
used by a patron of a telephone system. Even the _entire_ group of
property elements used by a patron in receiving telephone service
represents much less than what really is his proportion of the
service-rendering effort. What the patron receives is service and its
value during a time depends largely on how much of it he uses in that
time, and less on the number of telephones he can call.

_The cost of telephone service varies as the amount of use._ It is just,
therefore, that the selling price should vary as the amount of use.

=Rates.= There are two general methods of charging for telephone service
and of naming rates for this charge. These are called flat rates and
measured-service rates. The latter are also known as message rates,
because the message or conversation is the unit. Flat rates are those
which are also known as rentals. The service furnished under flat rates
is also known as unlimited service, for the reason that under it a
patron pays the same amount each month and is entitled to hold as many
conversations--send as many messages and make as many calls--as he
wishes, without any additional payment. In the measured-service plan,
the amount of payment in a month varies in some way with the amount of
use, depending on the plan adopted. The patron may pay a fixed base
amount per month, entitling him to have equipment for telephone service
and to receive messages, but being required to pay, in addition to this
base amount, a sum which is determined by the number of messages which
he sends. Or he may pay a base amount per month and be entitled to have