The modes of vibration of quartz piezo-electric plates as revealed by an interferometer

During the past five years considerable development has taken place in the piezo-electric quartz oscillator and resonator, chiefly in connection with their application to the production and measurement of radio-frequencies of great constancy or precision. A considerable literature has grown up dealing with the circuit arrangements and other practical details of construction found desirable or necessary by various workers in order to secure a satisfactory performance in the assemblage constituting a complete resonator or oscillator. This information is scattered throughout a considerable number of publications and for the most part must be considered as being of a disjointed nature. Bibliographies of the subject have, however, been drawn up by Cady, and more recently a critical resumé of the important literature has been collected in a monograph published by H. M. Stationery Office.