le]

Signal Code. The code by which stations are designated on
non-selective party lines usually consists in combinations of long and
short rings similar to the dots and dashes in the Morse code. Thus,
one short ring may indicate Station No. 1; two short rings Station No.
2; and so on up to, say, five short rings, indicating Station No. 5.
It is not good practice to employ more than five successive short
rings because of the confusion which often arises in people's minds as
to the number of rings that they hear. When, therefore, the number of
stations to be rung by code exceeds five, it is better to employ
combinations of long and short rings, and a good way is to adopt a
partial decimal system, omitting the numbers higher than five in each
ten, and employing long rings to indicate the tens digits and short
rings to indicate the units digit, Table X.

TABLE X

Signal Code
+--------------+---------------+--------------+---------------+
|STATION NUMBER|RING |STATION NUMBER|RING |
|1 |1 short |12 |1 long, 2 short|
|2 |2 short |13 |1 long, 3 short|
|3 |3 short |14 |1 long, 4 short|
|4 |4 short |15 |1 long, 5 short|
|5 |5 short |21 |2 long, 1 short|
|11 |1 long, 1 short|22 |2 long, 2 short|
+--------------+---------------+--------------+---------------+

Other arrangements are often employed and by almost any of them a
great variety of readily distinguishable signals may be secured. The
patrons of such lines learn to distinguish, with comparatively few
errors, between the calls intended for them and those intended for
others, but frequently they do not observe the distinction, as has
already been pointed out.

Limitations. With good telephones the limit as to the number of
stations that it is possible to operate upon a single line is usually
due more to limitations in ringing than in talking. As the number of
stations is increased indefinitely a condition will be reached at
which the generators will not be able to generate sufficient current
to ring all of the bells, and this condition is likely to occur before
the talking efficiency is seriously impaired by the number of bridges
across the line.

Neither of these considerations, however, should determine the maximum
number of stations to be placed on a line. The proper limit a