Progress in Wireless Telegraphy.

Progress, Volume III, Issue 2, 1 December 1907, Page 46

Progress in Wireless Telegraphy.

At the discourse delivered before the Royal Institution of Great Britain in the latter part of May, Dr. J. A. Fleming discussed recent contributions of electric wave telegraphy. In this he described the work which has been done of late, both along old lines and in some newer directions, notably in the field of directive radiation. Here the experiments made by Marconi, Braun, and himself were explained, and his ideas of the effects produced. Although this side of the work has not advanced far, some useful results have been becured, particularly those which enable a receiving station to determine, more or less definitely the direction from which the signals being received are coming. One phase of this work to which attention was called is the necessity of making a thorough study of the causes which vary the transparency of space to long electric waves. This effect was first noticed by Marconi, and later Fessenden described his own observations The transparency of the terrestrial atmosphere seems to vary from day to day and from hour to hour. It is better at night than m the daytime. There also seems to be another effect, differing possibly from the other, which is most noticeable near the transmitting antenna. This damping action fluctuates from hour to hour and from month to month, according to laws not yet determined, and too little is known to enable any generalization to be made concerning it It would seem that this large field offers great opportunities for the young investigator to exercise hismgenmty and energy tosomepurpose. Theproblem of wireless communication cannot be said to have been satisfactorily solved until more is known about the way m which the message is transmitted and about the interfering influences. When the art of telegraphy was invented the problem of transmission had to be solved. The same situation confronted the telephone, and until the laws governing the transmission of telephonic currents were fairly well understood, the art could not go forward. What is now needed for advancing wireless telegraphy, and what will do more in this direction than the invention of new receiving devices and new methods of setting up electric waves, is a painstaking and thorough study of the atmospheric conditions which afiect the radiation of these -waves. The field is, of course, large and difficult to explore, but that is all the more reason why well-directed efforts should be made in it At first thought it seems as though the work must be done on a working scale out of doors, yet it may not be impossible to devise some laboratory method of studying these actions which will enable the effects of various influences to be simulated and varied at will. It has been found in other arts that the conditions can be studied much better m a laboratory on a small scale. Even though not all of the effects can be introduced, some of them, at least, might be studied, and thus a better position gained for understanding the action of the others. — Electncal Review (N.Y.)'