January 5, 192.?] 



NATURE 



Fifty Years of Electrical Science. 



Fi/fy Years of Electricity: The Memories of an 

 Electrical Engineer. By Prof. J. A. Fleming. 

 Pp. xi + 371. (London: The Wireless Press, 

 Ltd., n.d.) 305. net. 



IN giving us his memories of the past fifty years, 

 Prof. Fleming has compiled a noteworthy 

 > ork. "The book makes no claim," he writes, 

 to be a systematic treatise on electricity or elec- 

 trical engineering, but is simply intended as an 

 attempt to place before the intelligent general 

 reader a .fairly comprehensive view of the chief 

 triumphs of applied electricity during the last 

 half-century." The intention is carried out with 

 the clearness of style and the lucidity of expres- 

 sion we have long learned to expect from the 

 author. He may be assured that, as he hopes, 

 it will " assist junior engineering students in 

 obtaining a preliminary acquaintance with the out- 

 lines of a subject they will study in greater detail 

 in other books," while to those who are not going 

 to be professional physicists or engineers it will 

 give a far more useful appreciation of what elec- 

 tricity is and what it has done than they gain 

 from their attempts to verify Ohm's law or 

 measure the magnetic moment of a piece of mag- 

 netised steel. Electrical progress lends itself in a 

 very special way to treatment of this kind, but if 

 it were possible to do for other branches of science 

 what Fleming has achieved for his the gain would 

 be very great. 



From Sturgeon, who in 1825 constructed the 

 first electro-magnet, to Einstein, whose work is 

 referred to in one of the later chapters of the book, 

 is nearly twice fifty years, but the work of the 

 first half of the period, though fundamental, is 

 passed over briefly in an introductory chapter. 

 We are reminded of the importance of Sturgeon's 

 discovery, of its extension by Joule and Faraday 

 and Henry, and its almost immediate application 

 to the electric telegraph by Cooke, Wheatstone, 

 and Morse, culminating in the Hughes printing 

 telegraph, for which the first U.S. patent was 

 secured in 1855; the laying of the first Atlantic 

 cable, 1857-58, which survived for only two 

 months; the work of William Thomson, Lord 

 Kelvin, based on his Royal Society paper of 1855 

 on "The Theory of the Electric Telegraph," lead- 

 ing to the mirror galvanometer (1858) and the 

 siphon recorder (1867) after the successful laying 

 of the 1866 cable. 



I-Hectrical telegraphy in England was at first 



developed entirely by private enterprise, and in 



1870, when the business was taken over by the 



State, the various companies owned altogether 



NO. 2723, VOL. 109] 



some 16,000 miles of lines. Up to this time, the 

 date at which Prof. Fleming's memories start and 

 his detailed history begins, electrical engineering 

 had been almost entirely concerned with tele- 

 graph work. The Society of Telegraph Engineers 

 and Electricians — afterwards to become the Insti- 

 tution of Electrical Engineers — was in 1870 the 

 only electro-technical society in England. 



But the seeds of a greater development had 

 been planted. Electro-magnetic induction was 

 discovered by Faraday in 183 1. From that 

 followed the early magneto machines of Saxton 

 (1833) and Clarke (1835); the Siemens armature 

 was devised in 1856, the Gramme ring by Paci- 

 notti in i860. Wilde, in 1850, had used electro- 

 magnets instead of permanent magnets for the 

 field-coils of a machine, and this was followed, 

 in 1867, by the invention of the dynamo ; the 

 machine became self-exciting. 



The account of these fifty years occupies some 

 fifty pages of Prof. Fleming's book; for the next 

 fifty the remaining 300 pages barely suffice. In 

 six chapters details are given of the advance in 

 all directions. Telegraphs and telephones, from 

 Hughes's first printing instrument and Graham 

 Bell's early telephone to the modern multiplex 

 type machines and the automatic telephone ex- 

 change, are all described. Then we have 

 dynamos, alternators, transformers, and motors, 

 from 1870 to 1920, from the first Gramme and 

 Siemens machines of some few kilowatts to the 

 giants of the present day. Another chapter treats 

 of electric lamps and lighting ; yet another of 

 supply stations, storage batteries, and railways ; 

 while fifty pages are devoted to electric theory 

 and measurements, from Kelvin and the work of 

 the first British Association Committee on Elec- 

 trical L^nits in 1861-62 to Maxwell and theories 

 of the ether, the discoveries of J. J. Thomson 

 and Rutherford, and the influence of Ein- 

 stein on modern physics. The final chapter 

 deals with wireless telegraphy. Commencing 

 with the theoretical work of Maxwell and 

 Hertz, it passes in review the experiments of 

 Hertz, Lodge, and Admiral Jackson, concluding 

 with those of Marconi and his associates. An 

 account is given of the valve detector devised by 

 the author in 1904, and of the improvement due 

 to Dr. Lee de Forest, by which it became the 

 triode valve and amplifier for wireless waves. 



This very brief resume will indicate the scope 

 and extent of the work. The limitations of space 

 prevent any detailed account, and indeed no such 

 account is necessary beyond the statement that 

 all important developments in electrotechnics of 

 the last fifty years are described with the well- 



