the operator, who cut off the battery by turning a switch and then inserted a plug in the line socket and received the call. The companion cord was then removed from the ground plate and inserted in the socket of the line called for. Mr. Doolittle states that on several
According to a local paper the switchboard erected in Philadelphia, in December, 1878, consisted of
In October, 1878, the parent 'Bell Telephone Company' issued a circular describing a form of brass strip switchboard 'adapted for six circuits.' On February 20, 1879, a circular was issued describing a switchboard which could be supplied at
Switchboard tap-bells were listed at $2.50 each; subscriber's hook district bells, $3.25 each; spring keys, 75 cents each; lightning arresters, 37 cents per circuit. It was stated that "the following plan it is