NATURE 



60 1 



THURSDAY, APRIL 30, 1896. 



THE INTELLECTUAL RLSE IN 

 ELECTRICITY. 

 The Intellectual Rise in Electricity : a History. By 

 Park Benjamin, Ph.D., LL.B., Member of the American 

 Institute of Electrical Engineers. Pp. (with index) 

 611. (London: Longmans, Green, and Co., 1895.) 



SINCE the days of the distinguished Joseph Priestley, 

 no physicist has ventured to give us series of 

 lessons on the history of the origin ^nd progress of 

 electrical science. In a large and admirable volume 

 entitled "Priestley on Electricity" the author of it tried 

 to introduce everything that was known up to his own 

 time, and he is a poor electrician who is not fully con- 

 versant with this gigantic labour. At last another author 

 has risen who has undertaken to supplement preceding 

 authors, and to put before the world in one volume the 

 subject of "the evolution of electricity" ; that is to say, 

 to describe the history of electrical science from its 

 origin up to the present day. The author who has 

 undertaken this task is Dr. Park Benjamin, LL.B., a 

 vriter from the other side of the Atlantic, who, it 

 must be said, has made himself fairly acquainted with 

 the many electricians who have preceded him, and who 

 makes an excellent effort to instruct the world at large 

 by bringing into what may be called a nutshell the 

 many pieces of information which he has been able to 

 collect and put together in a readable form. The work 

 is a large octavo, and consists of 611 pages, the whole 

 being written in a style which is as commendable to the 

 general scholar as to the particular electrician. The 

 greatest care has been taken, step by step, to supply such 

 illustrations as shall make the text comparatively easy. 

 There are also portraits of men who have been engaged 

 in the practical work of electricity ; and although we 

 would not compare the book with that written by 

 Priestley, we must candidly say of it that all teachers, 

 especially physical teachers, are certain to be benefited 

 by its perusal and intimate study. 



Like preceding writers. Dr. Park Benjamin, in tracing 

 back the history of electricity, believes that in the dawn 

 of civilisation the discovery of the force was connected 

 with the substance commonly known as amber. The 

 discovery of beads in the royal tombs of the Mycenae, and 

 at various places throughout Sardinia and the ancient 

 territory of Etruria, proves, he says, that trade in amber 

 existed in prehistoric times ; while the identity in 

 chemical constitution of the ornaments at Mycenae and 

 the Baltic amber from the tertiary formation of the 

 Prussian Samland, the coasts of Southern Sweden, and 

 the Northern Russian provinces, indicate the far distant 

 source from which the resin was anciently derived. Who 

 first brought the resin from the Baltic Sea to the Levant 

 is an undetermined question, as it is known to have come 

 across Europe by land as well as round the continent by 

 water. 



Giving full credit to the PhcEnicians for their enter- 

 prise, and with speculations as to the mode in which 

 amber may have travelled after its properties were first 

 discovered, Dr. Benjamin proceeds to consider the magnet, 

 NO. 1383. VOL. 53] 



or lodestone, and explains that the phenomena of the 

 lodestone are two-fold : it not only attracts iron objects, 

 but it has its polarity, or in other words exhibits its 

 opposite effects at opposite ends, by reason of which, 

 when in elongated form and supported so as easily to 

 turn, it will place itself nearly in the line of a meridian of 

 the earth, that is to say in a north and south direction. 

 This is its attractive tendency, or as William Gilbert 

 called it in 1600, its " verticity," and upon this duality, as 

 is well known, depends the use of the magnetic needle in 

 the mariners' compass. In the close of Chapter I., in 

 which reference is specially made to the magnet and to 

 iron as the substance upon which it acts, there is a short 

 but sound notice of history collected from Jewish and 

 Egyptian writers, which, though not strikingly convincing, 

 is of unquestionable interest. 



Getting lower down, Dr. Benjamin, as a matter of 

 course, quotes Thales, who many suppose to have been 

 the first man in the electrical field— though he lived 

 befo/e Christ— who understood the phenomena of 

 magnetic attraction, on which point Dr. Benjamin 

 remarks : 



" It must be admitted that even if Thales had been 

 cognisant of the amber phenomenon— that is to say, the 

 effects of rubbing amber and presenting it, in the excited 

 state, to the bits of straw which it attracts— it was not 

 logically necessary, from his point of view, to include it 

 specifically under his theory based upon the attraction of 

 the lodestone, and hence lack of mention does, on his 

 part, not imply lack of knowledge." 



Wading through pages of matter touching largely on 

 the Chinese origin of the compass and knowledge of the 

 Chinese in regard to the lodestone, Benjamin asserts 

 that no recorded evidence of the attraction of the magnet 

 or amber appears in the Chinese books of earlier date 

 than the fourth century of our era. He follows up 

 scientific records from the decline of the divine school of 

 Alexandria, which followed the period of the Ptolemies, 

 and explains that through the earlier centuries of the 

 Christian era we find the problem dealt with again and 

 again, sometimes purely physically, more often meta- 

 phorically ; sometimes by the poets, but with greater 

 frequency by the fathers and historians of the Church. 

 He quotes St. Augustine on the attraction of the magnet. 



" I was thunderstruck (' vehementer inhorrui ')• I saw 

 an iron ring attracted and suspended by the stone (lode- 

 stone), and then, as if it had communicated its own 

 property to the iron it had attracted and had made it a 

 substance like itself, this ring was put near another and 

 lifted it up ; and as the first ring clung to the magnet so 

 did the second ring cling to the first. A third and fourth 

 were similarly added, so that there hung from the stone 

 a kind of chain of rings with their hoops connected, 

 not interlinking, but attached together by their outer 

 surface." 



Gliding along and touching on the voyages of the 

 Northmen and the scientific writings of the Anglo- 

 Saxons, the works of William Appulus, the Anglo- 

 Norman magnetic knowledge, the labours of Alexander 

 of St. Albans (Alexander Neckham), the contemporary ot 

 Richard of England, son of Henry II., Dr. Benjamin puts 

 before us the first mariners' compass ; touches on the 

 penalty for falsifying the compass, and taking up 

 numerous statements and stories in relation not only to 



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