On the Theory of the Maintenance of Electric Currents by Mechanical Work without the use of Permanent Magnets,’ pp. 397-402 in Proceedings of the Royal Society of London, Vol. XV, No. 91, March, 1867. [Offered with:] SIEMENS, Carl Wilhelm. ‘On the Conversion of Dynamical into Electrical Force without the aid of Permanent Magnetism,’ pp. 367-369 [and:] WHEATSTONE, Charles. ‘On the Augmentation of the Power of a Magnet by the reaction theron of Current induced by the Magnet itself,’ pp. 369-372 in ibid., Vol. XV, No. 90, February, 1867.

[London:]: Taylor and Francis, [1867].

First edition, in the very rare original printed wrappers, of the first practical designs for a dynamo, made independently and almost simultaneously by Siemens and Wheatstone. Maxwell attended the February 1867 meeting of the Royal Society at which both papers were read, and he immediately worked out a theoretical analysis of the machines, which was published in the next number of the Proceedings (also offered here). “Siemens’ invention of the self-excited generator made possible a “second industrial revolution” characterized by the use of electrical energy in transportation, lightning and especially factory production. Siemens’s discovery replaced the inefficient steel magnets of the first generators with electromagnets, and allowed the harnessing of water or stream turbines to produce large amounts of electricity inexpensively. Paving the way for modern electric power technology, Werner [Siemens] obtained patent ... and secured a major position for his firm in the age of electricity” (Feldenkirchen, Werner Von Siemens: Inventor and International Entrepreneur, p. 87). The main difference between the two proposals was that in the Siemens design the armature was in series with the rotor, but in Wheatstone’s design it was in parallel. “Other inventors and scientists discovered the dynamo principle at about the same time; but Siemens foresaw the consequences of his “dynamo” for heavy-current, or power, uses and developed practical applications. His company pioneered in using electricity for streetcars and mine locomotives, in electrolysis, and in central generating stations” (DSB). The papers of Siemens and Wheatstone are here accompanied by “the pregnant, but almost totally forgotten, little paper in which Clerk Maxwell laid down a theory for self-exciting machines” (Silvanus P. Thompson, Dynamo-electric Machinery (1892), p. 20). Indeed, Maxwell’s ‘little paper’ was surprisingly omitted from the recent edition of his collected papers (edited by P. M. Harman, 2002), although it was included in the first collected edition (edited by W. D. Niven, 1890). This was not the only occasion on which an invention of Siemens’ stimulated Maxwell: his 1868 paper ‘On governors,’ which founded the subject of cybernetics, was written as an analysis of the ‘hydraulic-brake governor’ devised by Siemens.

The first electric generators were developed in the early 1830s by Michael Faraday (1791-1867), Anyos Jedlik (1800-95) and Hippolyte Pixii (1808-35), among others. None of those, however, achieved any practical significance and it was not until Henry Wilde (1833-1919), in the early 1860s, developed and patented the dynamo-electric machine, or self-energising dynamo, that it received any attention outside the community of physicists. Wilde’s dynamo replaced the permanent magnets of previous designs with electro-magnets and in so doing reached an enormous increase in power. The construction of the machine was considered nothing less than remarkable – not just because of its practical use, but also due to Wilde’s fondness for spectacular demonstrations, such as the ability of his machine to cause iron bars to melt, which he did not hesitate to show journalists, colleagues or anyone showing an interest in his invention. It was, however, not until the German brothers Ernest Werner and Charles William Siemens developed their “dynamo-electric machine” – and thereby coining the word “dynamo” – that the potential of the generator was fully exploited.

The Siemens dynamo was in all respects an immense leap forward and as opposed to the Wilde dynamo it was marketable. It could produce a steady and stable current, did not demand much maintenance and was easy to implement in factory production which consequently resulted in fierce competition to copy it. “The world’s most efficient dynamo with respect to producing electric current was the one that E. Werner and C. William Siemens, brothers working in Germany and England, respectively had patented. ... Menlo Park (Thomas Edison’s township) obtained a copy of the Siemens dynamo patent, but they were utterly unable to figure out how the Germans put the thing together. As Edison wrote to [Edward] Johnson, they “worked three days and nights on Siemens’ patent to figure out how the devil he connected up his armature and we never succeeded in doing it”” (McPartland, Almost Edison: How William Sawyer and Others Lost the Race to Electrification, p. 122).

Siemens’ discovery of the dynamo principle was first announced to the Berlin Academy of Sciences in January 1867, but it was not published in German until 1868 (‘Über die Umwandlungskraft von Arbeitskraft in elektrischen Strom ohne Anwendung permanente Magnete,’ in Monatsberichte der Königlichen Preußischen Akademie der Wissenschaften zu Berlin). Siemens and Wheatstone read their papers to the Royal Society on the same day in February 1867, but Siemens’ paper is dated February 4, while that of Wheatstone is dated February 14. Maxwell’s paper was received on February 28, 1867 and read on March 14.

The engineer and entrepreneur Carl Wilhelm Siemens (1823-83) was born near Hanover but settled in London in 1844, becoming a British subject in 1859. Beginning in 1850, he acted as English agent for Siemens & Halske of Berlin, the firm of his brother Ernst Werner (1816-92), a connection he maintained until 1858, when he became managing partner of the separate London firm founded under the same name. He was knighted a few months before his death. Sir Charles Wheatstone (1802-75) was appointed professor of experimental philosophy at King’s College, London, in 1834, and became a Fellow of the Royal Society two years later. He was responsible for many inventions and scientific discoveries in the Victorian era, notable the electric telegraph and the ‘Wheatstone bridge,’ a device for measuring electrical resistance. The first dynamo constructed by Wheatstone is still in the museum at King’s. James Clerk Maxwell (1831-79), widely regarded as the greatest theoretical physicist of the nineteenth century, was a colleague of Wheatstone’s at King’s from 1860 to 1865. This was probably the most productive period of Maxwell’s career, during which he developed his ‘dynamical theory of the electromagnetic field’ (1865).


Wheeler Gift 3562 [Siemens] (“This paper is remarkable for the introduction of the cumulative principle in the generation of the powerful currents”; 3570 [Wheatstone] (“The cumulative principle in the production of powerful currents clearly enunciated”); 3553 [Maxwell] (“The mathematical theory of dynamo-machines”). See Otto Mahr, Die Entstehung der Dynamomaschine (1941), pp. 129-49.



8vo (218 x 140 mm), pp. 355-389 [No. 90]; 389-416 [No. 91]. Original printed wrappers (no. 91 partly unopened). Both issues in fine condition.

Item #4305

Price: $950.00

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