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قراءة كتاب The Earliest Electromagnetic Instruments
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Transcriber’s Notes:
This is Paper 38 from the Smithsonian Institution United States National Museum Bulletin 240, comprising Papers 34-44, which will also be available as a complete e-book.
The front material, introduction and relevant index entries from the Bulletin are included in each single-paper e-book.
Corrections to typographical errors are underlined like this. Mouse over to view the original text.
SMITHSONIAN INSTITUTION
UNITED STATES NATIONAL MUSEUM
BULLETIN 240
SMITHSONIAN PRESS
MUSEUM OF HISTORY AND TECHNOLOGY
Contributions
From the
Museum
of History and
Technology
Papers 34-44
On Science and Technology
SMITHSONIAN INSTITUTION · WASHINGTON, D.C. 1966
Publications of the United States National Museum
The scholarly and scientific publications of the United States National Museum include two series, Proceedings of the United States National Museum and United States National Museum Bulletin.
In these series, the Museum publishes original articles and monographs dealing with the collections and work of its constituent museums—The Museum of Natural History and the Museum of History and Technology—setting forth newly acquired facts in the fields of anthropology, biology, history, geology, and technology. Copies of each publication are distributed to libraries, to cultural and scientific organizations, and to specialists and others interested in the different subjects.
The Proceedings, begun in 1878, are intended for the publication, in separate form, of shorter papers from the Museum of Natural History. These are gathered in volumes, octavo in size, with the publication date of each paper recorded in the table of contents of the volume.
In the Bulletin series, the first of which was issued in 1875, appear longer, separate publications consisting of monographs (occasionally in several parts) and volumes in which are collected works on related subjects. Bulletins are either octavo or quarto in size, depending on the needs of the presentation. Since 1902 papers relating to the botanical collections of the Museum of Natural History have been published in the Bulletin series under the heading Contributions from the United States National Herbarium, and since 1959, in Bulletins titled “Contributions from the Museum of History and Technology,” have been gathered shorter papers relating to the collections and research of that Museum.
The present collection of Contributions, Papers 34-44, comprises Bulletin 240. Each of these papers has been previously published in separate form. The year of publication is shown on the last page of each paper.
Frank A. Taylor
Director, United States National Museum
Contributions from
The Museum of History and Technology:
Paper 38
The Earliest Electromagnetic Instruments
Robert A. Chipman
ELECTROSTATIC INSTRUMENTS BEFORE 1800 123
INSTRUMENTING VOLTAIC OR GALVANIC ELECTRICITY, 1800-1820 124
ELECTRICAL INSTRUMENTATION, 1800-1820 125
OERSTED’S DISCOVERY 126
BEGINNINGS OF ELECTROMAGNETIC INSTRUMENTATION 126
CHRONOLOGY AND PRIORITY 127
ORIGINAL ELECTROMAGNETIC MULTIPLIERS 129
CONCLUSIONS 135
ACKNOWLEDGMENTS 136
Figure 1.—Models of various electromagnetic instruments created by Schweigger, Poggendorf and Cumming in 1821, made for an exhibit in the Museum of History and Technology, Smithsonian Institution. (Smithsonian photo 49493.)
THE EARLIEST ELECTROMAGNETIC INSTRUMENTS
The history of the early stages of electromagnetic instrumentation is traced here through the men who devised the theories and constructed the instruments.
Despite the many uses made of voltaic cells after Volta’s announcement of his “pile” invention in 1800, two decades passed before Oersted discovered the magnetic effects of a voltaic circuit. As a result of this and within a five-month period, three men, apparently independently, announced the invention of the “first” electromagnetic instrument. This article details the merits of their claims to priority.
The Author: Robert A. Chipman is chairman of the Department of Electrical Engineering at the University of Toledo in Toledo, Ohio, and consultant to the Smithsonian Institution.
Electrostatic Instruments before 1800
It is the fundamental premise of instrument-science that a device for detecting or measuring a physical quantity can be based on any phenomenon associated with that physical quantity. Although the instrumentation of electrostatics in the 18th century, for example, relied mainly on the phenomena of attraction and repulsion and the ubiquitous sparks and other luminosities of frictional electricity, even the physiological sensation of electric shock was