,28 



NATURE 



[February 2, 1893 



more rapidly by the British Post Office than by any private 

 undertaking, and we have certainly shot ahead of our smart 

 cousins on the other side of the Atlantic, from whom, how- 

 ever, I am proud to say, I learnt so much on my visits in 1877 

 and 1884. Their engineers are looking to us fo develop their 

 inventions, and we have done so. They cannot always get 

 them taken up in the States. Diplex, quadruplex, and multi- 

 plex telegraphy are importations from them, but they have been 

 improved in pur service by our own developments, and have 

 now become the staple and the standard modes of working. 

 No one has done more to effect this object than Mr. M. 

 Cooper. 



An accident in the drafting of the Act of Parliament of 

 1868-69 transferring the telegraphs from the hands of private 

 companies to that of the State, has led to a tremendous develop- 

 ment of newspaper reporting in England. Few people are 

 aware of the immense business done for the press. The growth 

 of press messages is shown in the fact that 21,701,968 words 

 paid for in 1871 have grown in 1891 to 600,409,000— an aver- 

 age of nearly 2,000,000 words per day. 



When Mr. Gladstone spoke at Newcastle, at the National 

 Liberal Federation, in 1891, 390,778 words were signalled to 

 different parts of the country. This kind of business is not, 

 however, confined to the Post Office. The Exchange Telegraph 

 Company, which commenced operations in 1872, working under 

 the license of the Postmaster-General, has in London over 800 

 instruments at work (120 being in newspaper offices), distri- 

 buting a daily average of 3,381,134 words to various receiving 

 instruments adapted to the requirements of the respective ser- 

 vices. The financial intelligence, for example, being trans- 

 mitted over instruments furnished with type-wheels containing 

 the various fractions most in use in Stock Exchange quotations. 

 The latest form of this instrument prints at the rate of forty 

 words per minute. General and parliamentary intelligence are 

 distributed to the clubs over column printers, and legal, sport- 

 ing, and Parliamentary news to newspapers on specially fast 

 tape printers, capable of delivering, in the hands of skilled 

 operators forty-five full words per minute to any number 

 of subscribers simultaneously. The news transmitted is 

 chiefly commercial and financial, amounting to 2,775,000 words 

 per day. 



To return to the purely State telegraphy. Some idea of the 

 growth of the general telegraphic business of the country may 

 be gathered from the following statement, which gives the total 

 number of messages paid for in each year : — 



In the course of his review of the history of submarine tele- 

 graphy, Mr. Preece said : — By far the greatest cable corporation 

 in the world is the Eastern Telegraph Company, whose system 

 of 25,376 miles stretches from Cornwall to Bombay, connects 

 the northern and southern shores of the Mediterranean with Malta, 

 and joins up the various other islands of the Mediterranean and 

 the Levant. This company, in conjunction with the Eastern 

 Extension and the Eastern and South African Companies, also 

 gains access to Australia and New Zealand on the one hand, 

 and to the Cape of Good Hope on the other, the combined 

 mileage reaching a total of m less than 47,151. This enormous 

 system has all grown up within, practically, the last 23 years. 



The form of cable has practically remained unaltered since 

 the original Calais cable was laid in 1851. Various sizes of 

 core and armour, and various modes of protection from decay, 

 have been used to suit different routes, but the cable of to-day 

 may be said to be typically the same as that used in the English 

 Channel in 1851, and in the Atlantic in 1865. 



The first cable had gutta-percha as a dielectric, and it is still 

 almost exclusively used for submarine cable core ; but the manu- 

 facture has so improved in the last twenty years that a core 

 having an insulator weighing 150 lbs. per naut, which then had 

 a dielectric resistance of .some 250 megohms a naut at 75° F., 

 can now be obtained, giving 20CO megohms at the same tempera- 

 ture. Indiarubber is creeping in, owing to the high price and 

 scarcity of gutta-percha. 



Next to strong tides, rocky bottoms, anchors, and shallow 

 water, the greatest enemy to submarine cables, more especially 



NO. 1214, VOL. 47] 



in the tropics, has proved to be the teredo of various species ; 

 but this depredatory worm has been utterly routed by covering 

 the gutta-percha core with a lapping of thin brass tape laid on 

 spirally. A remarkable thing about this little insect is that, 

 whereas twenty years ago it was practically unknown in our 

 English waters, it has now gradually spread all round our 

 coasts, with the exception, perhaps, of the North Sea. A new 

 cable about to connect Scotland and Ireland is being served 

 with brass tape. 



With the cables has grown up a fleet of telegraph ships to lay 

 and maintain them. In 1853 the Monarch, belonging to the 

 Electric Telegraph Company, was the only ship permanently 

 employed as a repairing telegraph ship ; now, in 1893, ^^e cable 

 fleet of the world numbers no less than 37, of which seven 

 belong to Government administrations and the rest to private 

 companies, the Eastern Telegraph Company heading the list 

 with five vessels. 



Perhaps the most remarkable history of a cable is the follow- 

 ing : — In 1859 the light cables laid in 1853 from Orfordness to 

 Holland were picked up and replaced by a heavier one. A few 

 nauts were sold to the Isle of Man Telegraph Company, and 

 had an extra sheath laid on. This cable was submerged between 

 that island and St. Bees, where it remained until 1885, when it 

 was replaced by a three-core cable. It was again put under 

 water in 1886 as part of the cable between Uist and Harris, in 

 the Hebrides, where it still lies, as good as ever. The dura- 

 bility of submarine cables is remarkable. That laid between 

 Beachy Head and Dieppe in 1861 is still working ; and that 

 laid between Beachy Head and Havre in 1870 has broken 

 within the last month for Xh^ first time. 



Despite the enormous growth of submarine cables during 

 these torty-two years, there would appear to be plenty of scope 

 for still further extension. The Pacific still remains untouched, 

 and the project is at the present time under consideration to 

 connect our possessions in North America with those in 

 Australia. 



The following is the passage relating to telephony :— I had 

 the good fortune in 1877 to bring to England the first pair of 

 practical telephones. They had been given to me in New York 

 by Graham Bell himself. After a series of experiments, I 

 brought them before the British Association meeting, which 

 was held that year at Plymouth. Who at that time could have 

 imagined that the instruments, which were then but toys, would, 

 within sixteen years, have become a necessity of commercial, 

 and almost of domestic, life ? Yet today the number of 

 telephones in actual use may pretty safely be put down at a 

 million ! 



During 1878 Edison devised his carbon transmitter, and 

 Prof. Hughes presented his "microphone" to the world. 

 These inventions made the telephone a practical instrument of 

 vast commercial importance. It may be said to have sprung 

 into existence well-nigh perfect ; and the fewness of the actual 

 improvements on the Bell receiver and the Hughes microphone 

 is scarcely more astonishing than the immense number of fruit- 

 less attempts at improvement that have been made. Even now 

 the original instruments are not easily beaten. 



The institution of telephone exchanges has led to a develop- 

 ment of systems of switching that might fairly be considered a 

 special study in themselves, and the demand for communication 

 between distant places has necessitated the application of much 

 special attention to the method of constructing lines and of 

 arranging circuits. 



It is in this latter field that I have been a diligent worker, 

 and the application of the so-called "K R" law has proved of 

 material benefit in connection with the problems of long-distance 

 telephony. It is a law which implies that the number of signals 

 that can be transmitted per second through any circuit depends 

 solely on the capacity (K) and the resistance (R) of the circuit. 

 It is very much the fashion to deny the accuracy of the K R law. 

 This is probably the result of ignorance of its meaning or of its 

 interpretation. Some speak of it as empirical, others scoff at it 

 as imaginary, and some sneer at it as an impossible law ; but 

 it is a law that has determined the dimensions and speed of 

 working of all our long submarine cables ; it determines the 

 number of arms a circuit can carry on the multiplex system, the 

 speed attainable- with the Wheatstqne system, and the distance 

 to which it is possible to work quadruplex ; it is a law that has 

 enabled us to bring London and Paris within clear telephone 

 speech of each other, and which will probably before the year 

 is out enable Dublin and Belfast to speak to London — a message 



