Long, short and intermediate wave lengths

I propose this evening to give a short account of wireless telegraphy and telephony, which may up to a point be historical, but which I hope will serve to illustrate the development of this interesting means of communication. Although this paper is entitled “Wave Lengths — Long, Short and Intermediate,” I propose to enlarge on this title, and go into some of the various theories, and peculiar characteristics of those particular frequencies used for the production of an ether wave, and its projection into space.