Correspondence: Piezoelectric crystals

In this issue of the PROCEEDINGS there appears an article by Professor Karl S. Van Dyke discussing the various conventions used with regard to quartz crystals and methods for establishing correct orientations in the crystal. He points out the need for standardizing on methods for designating crystals. This is a project in which we have tried to arouse interest without much success (original correspondance item from 1939 is included). In 1938 a pamphlet by the National Physical Laboratories appeared which attempted to standardize a notation with respect to quartz. It still appears desirable to have these matters considered by a standardizing committee. Since Professor Van Dyke has investigated the matter of terminology and conventions applicable to quartz rather completely, we suggest that he be appointed chairman of such a committee.