At times of pressure when race meetings are going on, or during the cricket and football seasons, the ordinary methods of working are supplemented by extraordinary means, thus: the duplex working between Bristol and Manchester is augmented by Manchester connecting there a Bristol wire with a Newcastle wire: Newcastle in like manner further connecting the line with Glasgow, Glasgow with Edinburgh, Edinburgh with Dundee, and Dundee with Aberdeen. Then at the Bristol end, instead of working by means of the ordinary keys, Wheatstone working is resorted to, viz.: the messages instead of being "keyed" are "punched," the punching process being performed by means of iron punching sticks upon an apparatus called the "perforator." The sticks are rapidly worked by skilful operators upon three steel keys, which, when struck, mechanically draw a strip of white paper tape, 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.