124 



NATURE 



[March 31, 1910 



charts. The author considers it most important that 

 the exact observational work at sea commenced under 

 the auspices of the Carnegie Institution should be 

 extended as soon as possible to all seas. He advocates 

 international cooperation to ensure continuity in the 

 drawings of magnetic lines in frontier districts, and 

 emphasises the importance of adequate determinations 

 of secular change. 



The terminology, units, &c., employed in the de- 

 scription of the charts are explained in pp. 30-31. The 

 charts themselves are divided into those dealing with 

 the whole or the greater part of the earth, those 

 confined to the oceans, those dealing with the several 

 continents, and, finally, those devoted to individual 

 countries or districts. The information given usually 

 includes the area, the epoch, the magnetic element or 

 elements dealt with, the interval — in specified units— 

 between the successive isogonal, isoclinal, or isomag- 

 netic lines, the geographical scale of the map, also 

 the locus and date of publication. The title in each 

 case, when there is one, is given in the original 

 language. There is a separate list on pp. 60-61 of 

 charts based on theory. 



The list of charts seems very complete. As evidence 

 that it is up to date may be mentioned th3 fact that 

 it includes the British and American world charts 

 published respectively in 1906 and 1907, Commander 

 Chetwynd's charts of the South Polar regions pub- 

 lished in 1908, Dr. Schmidt's charts of North Ger- 

 many, and Prof. Beattie's South African charts pub- 

 lished in 1909. The volume is clearly printed in good- 

 sized type, and should prove a valuable work of 

 reference. ^ C. Chree. 



ELECTRICAL BIOGRAPHY. 

 Makers of Electricity. By Brother Potamian and 

 Prof. James J. Walsh. Pp. vi + 404. (New York: 

 Fordham University Press, 1909.) 



THIS is not a work on central-station engineers, 

 but a series of biographical sketches of the chief 

 pioneers in the science of electricity in its historical 

 development. Of these sketches there are twelve, as 

 follows : — Peregrinus and Columbus ; Norman and 

 Gilbert ; Franklin and some of his contemporaries ; 

 Galvani; Volta ; Coulomb; Oersted; Ampere; Ohm"; 

 Faraday; Clerk Maxwell; Lord Kelvin. As the first 

 three, together with those on Oersted and Lord 

 Kelvin, are signed by Brother Potamian, it rnay be 

 assumed that the rest are by his colleague, Dr. 

 Walsh, who is the author of several others works, 

 "Makers of Modern Science," "Catholic Churchmen 

 in Science," "Makers of Modern Medicine," and 

 "The Popes and Science," which appear to have a 

 great vogue amongst Roman Catholic readers in the 

 United States. Brother Potamian, better known to 

 his English friends as Dr. O'Reilly, is one of those 

 who has made the bibliographical history of electricity 

 his own ; and his masterly annotations of the catalogue 

 of the Wheeler collection of electrical books (formerly 

 the library of the late Mr. Latimer Clark) in the 

 possession of the American Institute of Electrical 

 Engineers show him to possess abundant qualifica- 

 NO. 2109, VOL. 83] 



tions for writing biographies of the pioneers. If the 

 chapters on Peregrinus and Columbus, Norman and 

 Gilbert, add nothing to previous knowledge, they are 

 valuable in presenting very readable summaries of the 

 results of recent antiquarian research into the achieve- 

 ments of these early investigators of magnetism. The 

 account of Peregrinus is particularly good, and avoids 

 errors too often attaching to accounts of his long- 

 forgotten discoveries. The article on Gilbert is also 

 replete with the details which have been unearthed in 

 recent years, though by a slip on p. 49 he is said to 

 have blamed Stevinus for certain "vain and absurd" 

 views about the variation of the compass in southern 

 regions of the earth. It was not Stevinus whom he 

 blamed, but "certain unnamed Portuguese mariners." 

 Gilbert's Copernican views are discussed fully, and 

 criticised. 



Franklin's work in electrical observation is treated 

 at some length, as is natural in a work intended 

 jjrimarily for American readers ; but all readers should 

 be grateful for the very clear way in which Brother 

 Potamian has laid out the historical position of 

 Franklin with respect to those contemporaries of his — 

 De Romas, d'Alibard, and Divisch — who have been 

 alleged to have anticipated him with respect either to 

 the kite experiment or the invention of the lightning 

 rod. One amusing reminiscence is recorded in this 

 chapter of the controversy which arose upon knobs 

 versus points, and was referred to a committee 

 of the Royal Society. In that committee the Hon. 

 Henry Cavendish and Dr. Benjamin Wilson were 

 opposing partisans. Sir John Pringle, the President 

 of the Royal Society, supported Cavendish in favour ot 

 using points. But points had been advocated by 

 Franklin, whom to support at that moment was 

 "unpatriotic." His Majesty George III. accordingly 

 ordered that the points. of the lightning conductors at 

 Kew Palace should be replaced by balls ; whereupon 

 Sir John Pringle, replying with dignity, " Sire, I can- 

 not reverse the laws and operations of nature," re- 

 signed the presidency. This evoked the following 

 witty epigram : — 



While you, great George, for knowledge hunt, 

 And sharp conductors change to blunt, 



The nation's out of joint; 

 Franklin a wiser course pursues, 

 And all j'our thunder useless views 



By keeping to the point. 



The chapters devoted to Galvani and to Volta call 

 for little comment. That on Coulomb gives a better 

 biography than is accessible in English elsewhere. 

 Those on Oersted, Ampere and Ohm are each good in 

 their way; but that on Ohm lacks proportion. One 

 might think that the whole of mathematical physics 

 began and ended with Ohm's "Law." 



The lives of Faraday, Clerk Maxwell, and Lord 

 Kelvin are compiled with a knowledge and sym- 

 pathetic comprehension. The one phrase to which one 

 must take exception in the account of Lord Kelvin is 

 the suggestion — apropos of Lord Kelvin's saying at 

 his jubilee that the most strenuous of his efforts for 

 the advancement of science had ended in " failure " — 

 that "because Dame Nature did not open to his 



