Fleming, Hertzian Wave Telegraphy (1905); id., The Principles of Electric Wave Telegraphy and Telephony (2nd ed., 1910); J.
In the case of substances possessing anomalous dispersion, the direct measurement of the refractive index for Hertzian waves of very long wave-length may be employed.
Starting from an observation of Marconi's, a number of interesting facts have been accumulated on the absorbing effect of sunlight on the propagation of long Hertzian waves through space, and on the disturbing effects of atmospheric electricity as well as upon the influence of earth curvature and obstacles of various kinds interposed in the line between the sending and transmitting stations.4 Electric wave telegraphy has revolutionized our means of communication from place to place on the surface of the earth, making it possible to communicate instantly and certainly between places separated by several thousand miles, whilst The Electrician, 1904, 5 2, p. 407, or German Pat.
Rutherford used this detector to make evident the passage of an electric or Hertzian wave for half a mile across Cambridge, England.
It is now generally recognized that Hertzian wave telegraphy, or radio-telegraphy, as it is sometimes called, has a special field of operations of its own, and that the anticipations which were at one time excited by uninformed persons that it would speedily annihilate all telegraphy conducted with wires have been dispersed by experience.
Attendance at a lecture on Hertzian waves given by Sir Oliver Lodge at the Royal Institution in 1894 resulted in the Lodge-Muirhead syntonic system (see 26.538), which anticipated Marconi.
Birkeland (19) supposes the ultimate cause to be cathode rays emanating from the sun; C. Nordmann (24) replaces the cathode rays by Hertzian waves; while Svante Arrhenius (25) believes that negatively charged particles are driven through the sun's atmosphere by the Maxwell-Bartoli repulsion of light and reach the earth's atmosphere.
Fleming, The Principles of Electric Wave Telegraphy (London, 1906), chap. vii.; also Cantor Lectures on Hertzian wave telegraphy, Lecture iv., Journ.