Since 1821, historical accounts of the origins of electromagnetism seem to have limited their credit assignments for the conception and observation of this electromagnetic “doubling” effect (or “multiplying” effect, if the folding is repeated) to three persons. Almost without exception, however, these accounts have given no specific information as to precisely what each of these three accomplished, what physical form their respective creations took, what experiments they performed, and what functional understanding they apparently had of the situation. The usual statement is simply that a compass needle was placed in a coil of wire.[13] The main purpose of the present review is to recount some of these details.
The following are the three candidates whose names are variously associated with the “invention” of the first constructed electromagnetic instrument, or “multiplier,” or primitive galvanometer.
Johann Salomo Christoph Schweigger (1779-1857) in 1820 had already been editor for several years of the Journal für Chemie und Physik, and was professor of chemistry at the University of Halle.
Johann Christian Poggendorf (1796-1877) in 1820 had only recently entered the University of Berlin as a student following several years as an apothecary’s apprentice and a brief period as an apothecary. Four years later, he succeeded Gilbert as editor of the influential Annalen der Physik, a position he held for more than 50 years.
James Cumming (1771-1861) in 1820 was professor of chemistry at Cambridge University.
Chronology and Priority
The earliest established date in the “multiplier” record is September 16, 1820, when Schweigger read his first paper to the Natural Philosophy Society of Halle. There seems to be no reason to doubt that this report justifies the frequently used label “Schweigger’s multiplier.”
In an exuberant support of Schweigger’s position, Speter[14] with no mention of Cumming and no hint of “invention” details, shows that Poggendorf in 1821 admitted Schweigger’s priority, but suffered some lapse of memory 40 years later when writing sections of his biographical dictionary, leaving a distinct suggestion that the invention was his. Further confusion for later generations resulted from some ambiguous entries in the Allgemeine Deutsche Biographie of 1888. The name “multiplier” seems not to have originated with Schweigger himself. Speter credits it to Meineke as “working” editor of Schweigger’s Journal, but Seebeck seems to have used it much earlier.[15]
Conceding priority of conception to Schweigger (Cumming has not been a real competitor on this point) does not alter the fact that all three seem to have reached their results independently of one another, that the first work of each on this subject was published within a period of five months, that there were significant differences in their conceptions of the uses and the optimum design of their devices and that between them they provided an adequate foundation for the subsequent development of the galvanometer to become the primary electrical-measuring instrument.
In the matter of publication, Schweigger, as editor of what was popularly called Schweigger’s Journal, had an obvious advantage, and presented his experiments beginnings on page 1 of the first volume of his Journal for 1821, published January 1 of that year.[16] Oersted’s paper had appeared two volumes previously. He began by referring to Oersted’s discovery as “the most interesting to be presented in a thousand years of the history of magnetism.” He was, in fact, so impressed with the epochal nature of Oersted’s achievement that he commemorated it by giving his Journal a second title so that “volume one” of the new title could begin in the year after Oersted’s publication.