NATURE 



289 



THURSDAY, JULY 28, 1898. 



SUBMARINE TELEGRAPHS. 

 Submarine Telegraphs. By Charles Bright, F.R.S.E. 

 Pp.744. (London : Crosby Lockwood and Son, 1898.) 



IF experience, the possession of records, filial devotion, 

 and many friendships qualify a man to chronicle 



ontemporaneous events, Mr. Charles Bright is eminently 

 ;irepared to write a history in which his father played an 



nportant part. This book is full of information. It 

 ^tves evidence of great industry. It is well printed, 

 admirably illustrated, thoroughly indexed, and makes a 

 book of reference which should be in every engineer's 

 Jibrary. The literature of the subject has been very 

 meagre. Two or three text-books deal with the construc- 

 tion and working of cables. Many valuable papers are 

 scattered in the Proceedings of engineering institutions, 

 but there is no complete history of an industry that has 

 not yet attained its jubilee. Mr. Bright has fulfilled his 

 task very well. There is a remarkable free use of the 

 footnote system. Sometimes the footnote, the result of 

 subsequent inquiry, contradicts the text, but more often 

 it gives details useful to the engineer, but uninteresting 

 to the general reader. The book is divided into three 

 parts : history, construction, and working. In the first 

 part the evolution of the system of submarine telegraphy, 

 still in active progress and without any sign of finality 

 ahead, is lightly sketched. The days of secrecy have 

 ceased ; and manufacturers, engineers, and commercial 

 managers are equally ready to publish all they know. 

 The rough and tumble rule of thumb method of the 

 speculative pioneer has disappeared, and the results of 

 practical observation and scientific deduction control 

 the progress of the industry. It is very interesting to 

 note that the form of the first effective cable laid from 

 Dover to Calais in 185 1 has been but very little departed 

 from, but its details and dimensions have changed with 

 every requirement and for every ocean. Its development 

 has given a knowledge of the sea, of its bottom, of its 

 currents, and of its life, that has enlightened the 

 geographer and the biologist. Science has advanced 

 pari passu with engineering. The engineer has suc- 

 ceeded in interring many a foolish assumption in Davy 

 Jones' locker, and in bringing to light and illustrating 

 many a new condition undreamt of by the mathematician. 

 Mr. Bright points out that success was obtained in face 

 of scientific and public opinion. Even the Astronomer 

 Royal of the day (Airy) 



" had very foolishly stated that it would be impossible to 

 deposit the cable at so great a depth ; and that in any 

 case it was mathematically out of the question to transmit 

 electrical signals through such a length (p. 51). 



Now depth is no impediment ; there are twelve cables 

 opanning the North Atlantic. Fifty words a minute can 

 be sent across the ordinary Atlantic in each direction at 

 the same time, and it is pronounced by Mr. Preece even 

 not impossible to speak by telephone between New York 

 NO. 1500, VOL. 58] 



and London. The mileage of cable laid about the world 

 is 170,000, and 50,000,000/. has been invested in the 

 industry. The author avoids the prevalent mistake of 

 using the term "knot" as a standard of length. It is a 

 velocity, and the proper term for lengths is nautical miles 

 (N.M.) or "nauts." 



It should be recorded that the first money subscribed 

 for the construction and laying of a submarine cable to 

 cross the Channel, or indeed any sea, was 500/. each from 

 Mr. (afterwards Sir Charles) Fox, Mr. Francis Edwards, 

 Mr. J. W. Brett, and Mr. Charles J. Wollaston— the 

 last-named being still living. These formed " The 

 English Channel Submarine Telegraph Company" in 

 1850, and were the financial pioneers of the industry. 



The construction, laying, and repairing of cables are 

 very fully illustrated, the portion dealing with insulating 

 materials is instructive, and the methods of working, to- 

 gether with the speed of signalling, are gone into very 

 thoroughly. There is a want of agreement among ex 

 perts in adopting some standard of reference as regards 

 rate of working. Words per minute is very vague. What 

 is the length of a word ? Is it five letters, seven letters, 

 or even ten letters per word? Are abbreviations used 

 or not? Are the words ordinary or code? How many 

 elements are there allowed in a letter, and how much 

 is allowed for spacing ? What allowance is made for 

 skill ? The only true criterion of speed is the number 

 of complete waves that can be automatically and clearly 

 transmitted per unit of time, and even this will depend on 

 the sensitiveness and reliability of the apparatus used at 

 each end. 



Mr. Bright has executed his task in an impartial and 

 disinterested way. He has marshalled his facts with 

 much clearness, and the few errors detected are errors 

 of proof-reading, easily remedied in the next edition. 

 The most' notable omission is that of the modern im- 

 provements in repairing apparatus. There is no descrip- 

 tion of cutting grapnels, or of the ingenious automatic 

 signalling of the cable caught on the prongs of the 

 grapnel at the bottom of the ocean. Moreover, he has 

 not chronicled events in their chronological order, which 

 becomes occasionally embarrassing in tracing historical 

 sequence. 



The history of submarine telegraphy is an excellent 

 example of bold commercial enterprise, combined with 

 blind faith in the prowess of the engineer and deter- 

 mined perseverance in overcoming great difficulties. The 

 names of Cyrus Field and John Pender must always be 

 associated with those of Bright, Canning, Varley, Kelvin, 

 Clark, Siemens, and others, living and dead, who have 

 done so much to establish the industry on a sound 

 practical and commercial basis. Science, too, has bene- 

 fited largely in numerous ways by this very progress. 

 Physics, geography, biology and astronomy have each 

 gained new facts and new conditions. The accurate 

 determination of the longitudes of distant centres is no 

 mean advantage : that of Madras has recently been 

 measured with great skill. The columns of the Times 

 every morning skow how completely space has been 

 annihilated, and how the uttermost ends of the earth 

 are now virtually in London. 



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