9b-25a), which interrupts the comparison of the city to a ship, looks like an insertion whether by the prophet or by some other; but there is no good reason to doubt that the book is substantially the work of Ezekiel.
For the longest circuit to be worked, the shorter circuits being brought up approximately to a level, as regards resistance, by the insertion of resistance coils in the circuit of the transmitting apparatus of each shorter line.
In the earliest telephone switchboards the lines were connected to vertical conducting strips, across which were placed a series of similar horizontal strips in such a manner that any horizontal could be connected to any line strip by the insertion of a plug into holes provided in the strips for the purpose.
Operating mistakes also cause interruptions to conversations, as it is possible, by the insertion of a plug in a multiple jack, to disconnect the circuit between two talking subscribers.
An improvement in this respect has been effected by the insertion of condensers in the cord circuits, coupled with the use of two sets of impedance coils, one set on each.