at the same time perforating holes which indicate signs in accordance with the Morse alphabet system. These slips thus "punched"—which, by-the-by, very much resemble the perforated slips used in connection with the organette instrument—are passed through a Wheatstone "transmitter," and buzzed through so rapidly that 400 or 500 words can be sent in a minute. The signals are simultaneously reproduced upon blue slips in the form of dots and dashes at Manchester, at Newcastle, at Glasgow, at Edinburgh, at Dundee, and at Aberdeen. The message recorded on the slips is broken off at about every hundred words to form a "press" page at the receiving offices for writing up by the telegraphists, a large number of whom can be employed on the work at the same time. When this process is resorted to the battery power for the wire has to be greatly increased. The repeater instruments are worked in like manner, except that the system is permanent instead of occasional. The concentrator is a recent invention, and is used for the purpose of economising force and apparatus, and of minimising delay and table space. By its means the wires for eighteen
to twenty offices, which use the same form of telegraphic instrument, are led into a special switch-board, and each wire as it is required is "switched" through to a telegraph instrument, at which a clerk is ready to send or receive the message. Thus the telegraphist is "fed" by the operator at the concentrator, and has to send a message to any one of the thirty towns instead of, under ordinary working, to only three or four towns.
In place of over 700 batteries with 3,500 cells of the Bichromate, Daniel and Leclanche type in use at the Bristol telegraph office for many years, a system of accumulators or storage batteries has been brought into operation. The power for charging the accumulators is generated on the spot by a Crossley's gas engine driving a dynamo. The accumulators number 250, and each has seven divisions. The hexode instrument between Bristol and London requires a voltage of 400 dry cells. There are two complete sets of accumulators, each with separate connecting wires to the instrument room. One set is in use at a time. The system of accumulators has been introduced for the purposes of economy and saving of space.
It may be interesting to the uninitiated to learn that in telegraphy the earth plays the part of a return wire; thus the circuit between Bristol and Birmingham is rendered complete by earth. The wires connected with the two towns indicated are brought into the test boxes at the respective places, and there connected to a single wire at each town which finds earth by means of a zinc plate buried some twelve feet in the soil near or under the Post Office buildings.
Occasionally when people have been out for a drive or a cycle ride, and their eyes have been delighted with the grand scenery to be found around Bristol, they look, as they journey homewards, to the Government poles and to the many wires therefrom suspended, and wonder which are telegraph wires, which are telephone wires, where they all lead to, and between what points messages are sent and conversations held. Such travellers returning to Bristol by way of Almondsbury would see the wires on the one side (telegraphs), which run from Bristol to Falfield, Newport, Cardiff, Swansea, Gloucester, Liverpool; London to Swansea, Newport, and Cardiff; Birmingham to Exeter; Plymouth to
Liverpool; and (telephones) Bristol to Birmingham, Gloucester, Cardiff; and on the other side of the road (telephones) Horfield, Fylton, Almondsbury, Newport, Cardiff, Gloucester and Birmingham. In some instances there are two or three wires for the same place. The telegraph, and telephone wires cross and recross each other at frequent intervals along the road, and the whole sets of wires cross from side to side of the road between Fylton and Almondsbury.
Alternative routes for the wires are adopted where practicable, so that in case of a break-down on one line communication may be kept up on the other.
By way of illustration of such alternate routes, it may be mentioned that the two wires from the Head Post Office in Small Street for Swansea run underground to Stapleton Road, at which point they are brought above ground and diverge, one running to Wee Lane, thence to Ashley Hill, Horfield, Almondsbury, Alveston Ship, Falfield and Berkeley, up to the Severn Bridge; and the other branching off at the end of Stapleton Road, and carried along the Fishponds and Chipping Sodbury roads nearly to Yate, and down the Tortworth road to just beyond
Falfield, where it joins the other Swansea and South Wales wires, and passes over the Severn Bridge into Wales.