TABLE OF CONTENTS.
(The lines in italics which look like headings of paragraphs are really statements about experiments which were at that place shown.)
| 1. | Royal Institution Lecture on the Work | |
| of Hertz and some of his Successors:— | PAGES | |
| Biographical Introduction | [ 1] | |
| Elementary Explanation about Electrical Radiation | ||
| and Absorption and the Effect of Syntony | [3-8] | |
| Syntonic Leyden 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 Detector—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] | |
| Experiments showing Syntony | [27-28] | |
| Hypothesis concerning the Nature of Vision | [29-31] | |
| Summary of Various Detectors of Radiation | [30] | |
| Radiation Detected from extremely Weak Sparks, and by | ||
| very compact Receiver with Collecting Wire | [32-34] | |
| Vacuum Filings Tube | [34] | |
| Effect of Metallic Enclosure | [35-38] | |
| Experiments on Reflection, Refraction, and Polarisation | ||
| of Radiation | [39-42] | |
| Note about Electric Waves on Wires | [43] | |
| 2. | Application of Hertz Waves and Coherer | |
| Signalling to Telegraphy | [45-48] | |
| Coherer Behaviour and Tommasina’s Experiment | [49] | |
| Single-Point Coherer | [55] | |
| General Remarks about Patent Law | [50] | |
| Attempts at Syntonic Telegraphy | [52-60] | |
| Syntonic Radiators and Receivers | [51-56] | |
| 3. | Details of other Telegraphic Developments:— | |
| Popoff’s 1895 Demonstration | [60-62] | |
| Slaby’s Overland Experiments | [63-66] | |
| Marconi’s Recent Demonstration | [66-72] | |
| 4. | A History of the Coherer Principle | [73-87] |
| Professor Hughes’ Early Observations | ||
| before Hertz or Branly | [88-94] | |
| Work of Monsieur Branly | [95-108] | |
| 5. | Communications with respect to Coherer | |
| Phenomena on a Large Scale:— | ||
| Professor Elihu Thomson | [109] | |
| Dr. Morton | [111] | |
| 6. | Photo-Electric Researches of Drs. Elster | |
| and Geitel | [115-126] | |
| 7. | Photo-Electric Researches of Professor Righi | [127] |
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. O. J. Lodge before the Royal Institution of Great Britain on Friday evening, June 1, 1894. These notes have been revised by Dr. Lodge, and prepared for 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.