The attenuation of wireless waves due to the resistance of the earth

The paper calls attention to the present condition of knowledge on the subject of the attenuation of wireless waves travelling over the earth´s surface, due to energy absorption by the earth itself. The theories put forward on this problem by Sommerfeld and Zenneck are briefly outlined, and it is shown that the latter has taken account only of a special case of the more general theory of Sommerfeld. The results deduced from this theory have been worked out for some typical practical cases of both short- and long wave transmission, but, owing to the complete lack of experimental evidence, no practical test of the theory has yet been made. In view of the importance of a knowledge of ground absorption in connection with the complete study of the propagation of wireless waves of all lengths over the earth´s surface, it is highly desirable that a systematic experimental investigation should be carried out in the near future.