tored automatically, claiming that the operator has plenty of
time to restore the drops by hand while receiving the order from the
calling subscriber or performing some of her other work. Those who
think this way have claimed that the only place where an automatically
restored drop is really desirable is where, on account of the lack of
space on the front of the switchboard, the drops are placed on such a
portion of the board as to be not readily reached by the operator.
This resulted in the electrically restored drop, mention of which will
be made later.

Others have contended that even though the drop is mounted within easy
reach of the operator, it is advantageous that the operator should be
relieved of the burden of restoring it, claiming that even though
there are times in the regular performance of the operator's duties
when she may without interfering with other work restore the drops
manually, such requirement results in a double use of her attention
and in a useless strain on her which might better be devoted to the
actual making of connections.

Until recently the various Bell operating companies have adhered, in
their small exchange work, to the manual restoring method, while most
of the so-called independent operating companies have adhered to the
automatic self-restoring drops.

Methods of Automatic Restoration. Two general methods present
themselves for bringing about the automatic restoration of the drop.
First, the mechanical method, which is accomplished by having some
moving part of the jack or of the plug as it enters the jack force the
drop mechanically into its restored position. This usually means the
mounting of the drop and the corresponding jack in juxtaposition, and
this, in turn, has usually resulted in the unitary structure
containing both the drop and the jack. Second, the electrical method
wherein the plug in entering the jack controls a restoring circuit,
which includes a battery or other source of energy and a restoring
coil on the drop, the result being that the insertion of the plug into
the jack closes this auxiliary circuit and thus energizes the
restoring magnet, the armature of which pulls the shutter back into
its restored position. This practice has been followed by Bell
operating companies whenever conditions require the drop to be mounted
out of easy reach of the operator; not otherwise.

_Mechanical--Direct Contact with Plug._ One widely used method of
mechanical restorati