Wireless Telegraphy and Telephony Simply Explained: A Practical Treatise

Alfred Powell Morgan

• Publisher: Library of Alexandria
• Year: 2021
• eBook ISBN: 9781465664594
• Topic: Literature
• Subtopic: Literature General
• Index: Literature

Wireless telegraphy, that marvelous art which has made possible the instantaneous transmission of intelligence between widely distant parts having no apparent physical connection save that of the earth, air, and water, is one of those wonders of science which appeal to the average mind as either incomprehensible or only explainable through the use of highly technical language. Contrary to this general opinion, however, the whole theory and practice of the wireless transmission of messages is capable of the simplest explanation. Throw a stone into a pool of water. A disturbance is immediately created, and little waves will radiate from the spot where the stone struck the water, gradually spreading out into enlarging circles until they reach the shores or die away. By throwing several stones in succession with varying intervals between them it would be possible to so arrange a set of signals that they would convey a meaning to one who is initiated, standing on the opposite side of the pool. The little waves are the vehicle which transmits the intelligence, and the water the medium in which the waves travel. Wireless telegraph instruments are simply a means for creating and detecting waves in a great pool of ether. Scientists suppose that all space and matter is pervaded with a hypothetical medium of extreme tenuity and elasticity, called luminiferous ether, or simply ether. Although ether is invisible, odorless, and practically weightless, it is not merely the fantastic creation of speculative philosophers, but is as essential to our existence as the air we breathe and the food we eat. By imagining and accepting its reality, it is possible to explain and understand many scientific puzzles. The universe is a vast pool of ether. It is all-pervading. There is no void. It is diffused even among the molecules of which solid bodies are composed. The study of this substance is, perhaps, one of the most fascinating and important duties of the physicist. Ninety million miles away from our earth is a huge flaming body of vapors and gases, called the sun. This seething mass of flame and heat furnishes us more than mere winter and summer and night and day, for we on this earth are not living on our own resources, and the real work of the world so necessary for even bare existence is accomplished by the energy of the sun stored up in coal, in plants and trees and mountain torrents. Light is known to be vibrations of an extremely rapid period—electromagnetic waves, they are called. Heat can be shown to be of the same nature. Traveling at the rate of over 180, 000 miles per second, these two great gifts of the sun come streaming continually down to us over the inconceivable distance of almost 100, 000, 000 miles. Both require a medium for their propagation. The ether supplies it. It is the substance with which the universe is filled. Incidentally it is also the seat of all electrical and magnetic forces.

Table of contents

• Wireless Telegraphy and Telephony Simply Explained
• CHAPTER II. THE MEANS FOR RADIATING AND INTERCEPTING ELECTRIC WAVES. AERIAL SYSTEMS. EARTH CONNECTION.
• CHAPTER III. THE TRANSMITTING APPARATUS.
• CHAPTER IV. THE RECEIVING APPARATUS.
• CHAPTER V. TUNING AND COUPLING, DIRECTIVE WAVE TELEGRAPHY.
• CHAPTER VI. THE DIGNITY OF WIRELESS. ITS APPLICATIONS AND SERVICE. WIRELESS IN THE ARMY AND NAVY. WIRELESS ON AN AEROPLANE. HOW A MESSAGE IS SENT AND RECEIVED.
• CHAPTER VII. THE EAR. HOW WE HEAR. SOUND AND SOUND WAVES. THE VOCAL CHORDS. THE STRUCTURE OF SPEECH.
• CHAPTER VIII. THE TELEPHONE TRANSMITTER AND RECEIVER. THE PHOTO PHONE. THE THERMOPHONE. THE SELENIUM CELL. THE SPEAKING ARC.
• CHAPTER IX. THE WIRELESS TELEPHONE.
• CATALOGUE OF GOOD, PRACTICAL BOOKS