Book description
ELECTROMAGNETIC THEORY by JULIUS ADAMS STRATTON. PREFACE: The pattern
set nearly 70 years ago by Maxwell's Treatise on Electricity and
Magnetism has had a dominant influence on almost every subse quent
English and American text, persisting to the present day. The Treatise
was undertaken with the intention of presenting a connected account of
the entire known body of electric and magnetic phenomena from the single
point of view of Faraday. Thus it contained little or no mention of the
hypotheses put forward on the Continent in earlier years by Riemann,
Weber, Kirchhoff, Helmholtz, and others. It is by no means clear that
the complete abandonment of these older theories was fortunate for the
later development of physics. So far as the purpose of the Treatise was
to disseminate the ideas of Faraday, it was undoubtedly fulfilled; as an
exposition of the author's own contributions, it proved less successful.
By and large, the theories and doctrines peculiar to Maxwell the concept
of displacement current, the identity of light and electromagnetic
vibrations appeared there in scarcely greater completeness and perhaps
in a less attractive form than in the original memoirs. We find that all
of the first volume and a large part of the second deal with the
stationary state. In fact only a dozen pages are devoted to the general
equations of the electromagnetic field, 18 to the propagation of plane
waves and the electromagnetic theory of light, and a score more to
magnetooptics, all out of a total of 1,000. The mathematical
completeness of potential theory and the practical utility of circuit
theory have influenced English and American writers in very nearly the
same proportion since that day. Only the original and solitary genius of
Heaviside succeeded in breaking away from this course. For an
exploration of the fundamental content of Maxwell's equations one must
turn again to the Continent. There the work of Hertz, Poin car6,
Lorentz, Abraham, and Sommerfeld, together with their associates and
successors, has led to a vastly deeper understanding of physical
phenomena and to industrial developments of tremendous proportions. The
present volume attempts a more adequate treatment of variable
electromagnetic fields and the theory of wave propagation. Some atten
tion is given to the stationary state, but for the purpose of
introducing fundamental concepts under simple conditions, and always
with a view to later application in the general case. The reader must
possess a general knowledge of electricity and magnetism such as may be
acquired from an elementary course based on the experimental laws of
Coulomb, Amp& re, and Faraday, followed by an intermediate course
dealing with the more general properties of circuits, with thermionic
and electronic devices, and with the elements of electromagnetic
machinery, termi nating in a formulation of Maxwell's equations. This
book takes up at that point. The first chapter contains a general
statement of the equations governing fields and potentials, a review of
the theory of units, reference material on curvilinear coordinate
systems and the elements of tensor analysis, concluding with a
formulation of the field equations in a space-time continuum.
