This book is a completely revised and rewritten edition of "Electric
Contacts Handbook" published in 1958. A large number of new in-
vestigations are considered, and many of the basic theories are revised
in detail and even in general. The body of information had to be limited
as it was not advisable to increase the volume of the book. In
particular, no attempt was made to cover all of the practical
applications. They appear as examples following concentrated
explanations of basic phenomena. As in several branches of technology,
the solutions of problems ari- sing in the field of electric contacts
involve insight into various disci- plines of physics. It is feit that
reviews of some of those topics, especi- ally adapted to electric
contact phenomena, are welcome to many readers. For example, chapters
have been devoted to the structure of carbon, the band theory of
electric conduction in solids, certain pro- blems in statistics, and the
theory of the electric arc. As regards arc problems, new ideas have been
introduced. In order to make the main text less cumbersome, such reviews
are presented as appendices. Throughout this edition, the mksa-unit
system is used in accord with the latest recommendation for
standardization of units in scientific and technical writings. The
chapter "History of Early Investigations on Contacts" forming Part IV in
the preceding edition of 1958 has not been repeated in this book.
