Relativity in oblique coordinates

During the past three years Professor Vladimir Karapetoff has given talks on “Straight-Line Relativity in oblique coordinates” before several Institute Sections, as well as at some conventions of other societies, and has demonstrated his “blue and red” mechanical model of Einstein´s fundamental relations. Institute members and readers of the JOURNAL will be interested to know that an article by Professor Karapetoff, containing a detailed elementary theory of restricted relativity in his oblique coordinates and a description of the model, has appeared in the August issue of the Journal of the Optical Society of America. Professor F. K. Richtmyer, Cornell University, Ithaca, N. Y., is the feusiness Manager of the Journal; the price of single issues, as long as they last, is 60 cents.