The oscillograph and its uses

The usefulness of a satisfactory method of observing or recording the wave forms of rapidly varying electric currents and pressures has been appreciated almost from the time that investigators and designers commenced working with electrical apparatus. The various methods which have been used for obtaining these records or indications have had, and are having, an important influence on the design of apparatus and a clearer understanding of the phenomena accompanying their use. It is the purpose of this paper to outline briefly the steps which have led up to the methods in use at the present time, and to describe more fully the devices which are now most employed and the uses to which they may be put.