At the death of Wesley the figures were: 313 preachers, 119 circuits and mission stations, and members.
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.
If long circuits were worked direct with ordinary instruments, high battery power would be required in order to send sufficient Single current to actuate the apparatus.
One of the longest circuits upon which it has been successfully worked is that between St Petersburg and Omsk, a distance of approximately 2400 miles of iron wire, with three repeating stations.
The heavier cores, with the consequent advance in speed of working attainable, have necessitated the introduction of automatic sending, the instruments adopted being in general a modification of the Wheatstone transmitter adapted to the form of cable signals, while the regularity of transmission thus secured has caused its introduction even on circuits where the speed cannot exceed that of the ordinary operator's hand signalling.