May 13. 1875J 



NATURE 



opposite motion, while in its neutral position it is free 

 from contact. Thus contact with the paper will produce 

 marks, either dot or dash, according as the inking con- 

 tact is either momentary or of a sensible duration ; the j 

 contrary movement producing the spacing between the 

 printed marks. Now, as the currents from the Jacquard 1 

 ribbon (Fig. 20) are passed at equal intervals and in ! 

 alternate directions, the spacings between the signals will { 

 be automatically regular ; the " dash " being the effect { 

 of the retention of the magnetic armature acting on the ! 

 inking disc for double the time of the " dot "jby reason of j 

 the grouping of the perforations to form the " dash," giving j 

 a longer duration without a reversal of the current being 

 passed into the circuit. The arrangement for supplying 

 ink to the little revolving inking disc is simple and effec- 

 tive. A metal wheel, having its edge cut into a V shape, 

 is kept revolving in a dish of ink, and by capillary attrac- 

 tion this V groove is kept constantly filled with ink, 

 and thus the periphery of the little inking disc which 

 revolves in this groove of ink is without any rubbing 

 friction kept constantly supplied with the proper amount 

 of ink to continuously record the rapid motion of the 



armature as the currents flow from the transmitter into 

 the wire. It is by these very simple means that Wheat- 

 stone has produced his high-speed printer, at once an 

 accurate recorder and a telegraphic necessity in these 

 days of special press-transmissions to the chief com- 

 mercial centres of the United Kingdom. 



In order to realise the great value of the automatic 

 high-speed system upon extended lines of telegraphic 

 transmissions, it is only necessary to compare the speed 

 of the Morse apparatus on lines of a given length with 

 that of the automatic electric Jacquard weaver. With an 

 apparatus combining such celerity of transmission and 

 recordmg powers, it becomes necessary to adopt a special 

 system for the despatch and receipt of intelligence ; to 

 economise manual labour, and utiUse the capacity of the 

 wire to the greatest extent. Messages are therefore passed 

 into the machine for transmission along the wire in groups ; 

 that is to say, on a circuit of 300 miles in length, twelve 

 messages will be perforated upon a continuous ribbon and 

 sent through the "transmitter" at the same time, and 

 vice versa. Employing a wire of a capacity known as 

 No. 8 Birmingham wire gauge over this distance, four 



Fig. 25— Alexander Bam's. Automatic Chemical Printing Telegraph 



distinct groups consisting of twelve messages of thirty 

 words each can be forwarded, and three similar groups 

 received, in an hour ; equivalent to eighty-four messages 

 of thirty words each, and with the average of five letters 

 to a word, a total of 12,600 letters, or an average of 210 

 letters per minute, equivalent to forty-two words per 

 minute, with all the necessary formahties and acknow- 

 ledgments in addition. Such a speed may be maintained 

 in moderately fine weather, and requires a staff of five 

 clerks at both the receiving and transmitting stations ; 

 namely, two for perforating the messages on to the paper 

 ribbon, two for writing or translating, and one for the 

 working of the apparatus in sending acknowledgments 

 and signals for repetitions, &c. When dealing with 

 parliamentary and newspaper despatches, a much higher 

 speed can be obtained, first because there is no neces- 

 sity for grouping the messages, and secondly because, as 

 a rule, the transmissions are only in one direction, 

 either as wholly received or forwarded messages, which 

 circumstances greatly reduce the initial delay in the 

 transmission. With a No. 4 wire gauge between Aber- 

 deen and London, forty words may be reached, and with 



a No. 6 wire between Edinburgh and London fifty words, 

 between Newcastle-upon-Tyne and London sixty words, 

 and between Glasgow and Liverpool 120 words maybe 

 recorded. The shorter the length of the line, the greater 

 the speed obtained. A very rapid form of a chemical 

 automatic printing telegraph has been designed in America, 

 based upon Alexander Bain's chemical automatic printer, 

 1846. This American chemical automatic machine has 

 sent and printed, under favourable conditions, intelligence 

 between Washington and New York, a distance of 282 

 miles, at a speed of 1,050 words or about 5,250 letters 

 per minute, at which rate the apparatus required ten per- 

 forators, thirteen copyists, and two instrument- operators 

 to keep the circuit supplied and the transmissions trans- 

 cribed for general circulation. How far such a speed can 

 be profitably employed for telegraphic purposes remains 

 to be developed. It is quite possible to transmit intelli- 

 gence beyond a profitable speed, for, irrespective of the 

 difficulty of always commanding a sufficient amount of 

 intelligence to keep the apparatus fully employed, the vast 

 staff of manipulators necessary to ensure the preparation 

 of the Jacquard ribbon, and translation of the symbolic 



