Signalling Across Space Without Wires: Being a Description of the Work of Hertz & His Successors (Classic Reprint)

SIGNALLING THROUGH SPACE WITHOUT WIRES. THE WORK OF HERTZ and SOME OF HIS SUCCESSORS. The following pages (up to page 42) are the Notes of a Lecture delivered by Dr. 0. J. Lodge beforo the Royal Institution of Great Britain on Friday evening, June 1, 1894. These notes have been revised by Dr. Lodge, and prepared ibr publication in the form here presented. After page 42 an account is given of the later applications of Hertzian -wave experiments to wireless telegraphy, and a series of Appendices are also given. Introductory.-1894. The untimoly end of a young and brilliant career cannot fail to strike a note of sadness and awaken a chord of sympathy in tho hearts of his friends and fellow-workers. Of men thus cut down in the early prime of their powers there will occur to us here the names of Fresnel, of Carnot, of Clifford, and now of Hertz. His was a strenuous and favoured youth ; he was surrounded from his birth with all the influences that go to make an accomplished man of scie

Table of Contents

TABLE OF CONTENTS; (The lines in italics whichlook like headings of paragraphs are really statements about experiments which were at that place shown); Royal Institution Lecture on the Work of; Heetz and some of his Successors :- pages; Biographical Introduction 1; Elementally Explanation about Electrical Radiation and; Absorption and the Effect of Syntony 3-8; Syntonic Ley den-Jar Experiment 6, 21; Side Observations on the Effect of Light on Electric; Discharge •« ••• 9-12; Various Detectors of Radiation • 13-23; Physiological Non-Effect of Sufficiently Rapid Alternations 17; Boltzmann Gap Dete ;tor-the Precursor of the Coherer 18; Branly's Observations (see also Appendix, page 95) 20; Early Form of Coherer and of Branly Filings Tube 21-23; Early Signalling over 40 or 60 yards 24-25; Use of Telephone as Receiver 26; E