to ring upon the composited lines, so
that nothing is lost while revenue is gained.

=Two-Number Calls.= In cases where the traffic between communities is
large, where the rate is small, and where the conversations are short
and more on the general order of local calls, it is usual to handle the
switches exactly as local calls are trunked between central offices of
the same exchange. That is, the subscriber's operator who answers the
call trunks it, by the assistance of a call circuit and an incoming
trunk operator. The subscriber's operator records only the numbers of
the calling and called subscribers. No long-distance operators at all
assist in these connections. They are known as "two-number calls." The
calling subscriber remains at his telephone until the conversation is
finished.

=Particular-Party-Calls.= In cases where the traffic is smaller, and
where the rate is large, it is customary to handle the calls through
long-distance operators. The ticket records the particular party wished,
and the calls are named "particular party" calls. In such connections
the calling patron is allowed to hang up his receiver, after his call is
recorded, and is called again when his correspondent is found and is
ready to talk. This makes _all calls for conversations_ outgoing ones.
Only recording operators receive calls _from_ patrons. Line operators
make calls _to_ patrons.

=Trunking.= Long-distance lines entering a city usually terminate in one
office only, no matter how many offices the local exchange may have. It
is possible to terminate these long-distance lines on a position of the
multiple switchboard for local lines. For a variety of reasons this is
not practiced except in special cases. The usual method is to terminate
them in a special long-distance board and to provide trunk lines from
this board to the one or more local switchboards of the exchange. In
common-battery systems these toll trunks are so arranged that the called
local subscriber receives transmitter current from the office nearest to
him, yet is able to show the long-distance operator the position of his
switch hook and is able to be called by the long-distance operator
without the intervention of the switching operator in the local office,
even though two repeating coils may be in the trunk circuit.

_Through Ringing._ There is a distinct traffic advantage in having the
ringing of the subscriber under the control of the long-distance
operator. The lat