Wireless telephony

“ The apparatus used as developed by the engineers of the Bell system was in a measure an outgrowth of their work with the long-distance telephone. Wireless telephony, despite the wonders it has already accomplished, is still in its infancy. With more perfect apparatus and the knowledge that comes with experience we may expect that speech will girdle the earth.
It is natural that one should wonder whether the wireless telephone is destined to displace our present apparatus. ”

“ Wireless telephony, like wireless telegraphy, but to an even greater extent, is peculiarly suited for the conveyance of marine intelligence. Wireless telephony occupies a unique position in this regard-no operator is required. The additional expense of an operator is an objection to the wireless telegraph in many cases, and forbids its installation. Anybody can operate the wireless telephone. It is also much quicker-words can be spoken more rapidly than they can be put into Morse signals and translated. ”

“ The aerial wire is precisely the same for either wireless telegraphy or wireless telephony. The transmitter of a wireless telegraph set generally uses a spark gap for setting up the electric oscillations, while usually for wireless telephony a vacuum tube is employed for this purpose. The receptor for wireless telegraphy and telephony is the same and may include either a crystal detector or a vacuum tube detector, as will be explained presently. ”

“ FIG. 153.—The aerial system of a transatlantic station.
The wireless telephone enables a passenger on board ship to communicate direct with his home by relaying the message over the line wires. By the same means the captain of a ship can call his home office and communicate with the owner of the vessel.
Telegraphs and telephones are the nerves of the world, carrying swift messages from its brain centers to its hands, annihilating distance in thought. All differences between men as individuals and people as nations can be traced to the lack of close contact. ”

“ To make wireless telephony a success it was necessary to find some way of making perfectly uniform carrier-waves, and then of loading on them waves of speech. Of course, the latter are not sound-waves, because they are not waves of air, but they are electro-magnetic waves corresponding exactly to the sound-waves of air and at the receiving-end they affect the telephone receiver in the191 same way that it is affected by the electric waves which are sent over telephone wires. ”

“ In the first place, wireless telephony is now, and probably always will be, very expensive. Where the wire will do it is the more economical. There are many limitations to the use of the other for talking purposes, and it cannot be drawn upon too strongly by the man of science. ”

“ Wireless telephones will not only transmit the speech more clearly and distinctly, but have the further advantages that the initial cost is very much lower than that of wire lines, the maintenance is almost nil in comparison, the depreciation is smaller, the number of employees required is less, and a break-down is limited to the inside of the station, where it could be quickly remedied by the substitution of a duplicate spare piece of apparatus. ”

“ By means of wireless telephony the transmission of intelligence is far more direct and expeditious, and in times of emergency this not unfrequently becomes a very vital question indeed. An important characteristic of wireless telephonic communication is the exceptional clearness of the articulation, owing to the absence of the electrostatic capacity of metallic lines and cables which is always present in wire telephony. ”

“ There is a very decided field of opportunity for wireless telephony for long-distance work. The present systems of long-distance wires are very expensive to construct and maintain, and are subject to the whims of storms and the elements. ”

“ Scientists attacked the problem with vigor, and various means of wireless telephony were developed, without any being produced which were effective over sufficient ranges to make them really useful.
Probably the earliest medium chosen to carry wireless speech was light rays. A microphone transmitter was arranged so that the vibrations of the voice would affect the stream of gas flowing in a sensitive burner. The flame was thus thrown into vibrations corresponding to the vibrations of sound. ”

“ In these progressive times it is only reasonable to expect that some attempt would be made to utilise the ether-waves for other purposes than that of telegraphic communication, and already many clever minds are at work trying to solve the problems of the wireless control of torpedoes and airships, wireless telephony, and, last but not least, the wireless transmission of photographs. ”

“ During some of the winter storms and blizzards, when miles of wires were down in all directions, wireless has been the sole means of communication in certain instances.
The process of sending a wireless message is very simple. The aerial switch is usually kept in such a position that the receiving instruments are connected to the ground and aerial so that the operator is always able to hear any one calling him. We will suppose for illustration that the land station at 42 Broadway, New York City, wishes to transmit a message to the steamer "Horatio Hall." ”

“ Just the same, only in radio telephony we are confronted by a problem not met with in wireless telegraphy. We have not only to transmit sound, such as isolated dots and dashes, but to send through the air every rise and fall and inflection of the human voice just as it is recorded in the minute lines of a phonographic record. ”

“ We still have our neighbors' call bells, and we could listen to their messages if we were gossips. The telephone service has been extended to great distances—for instance, from Boston to Omaha—not by relays, but by strengthening the blows upon the medium between the transmitting circuit and the receiving one, just as we desire to do in what is called wireless telegraphy, the apparatus of which is almost identical in principle to that employed in telephony. The individual call in telephony is not a success for nearly the same reasons that exist in the case of wireless telegraphy. ”

“ One of the greatest disadvantages of most systems of wireless telegraphy lies in the fact that no arrangement is provided for simultaneously transmitting and receiving wireless signals. It is usually necessary for one operator listening to another to have to wait until the finish signal is given before he can reply or interrupt in case he cannot understand part of the message, because the receiving apparatus of the transmitting station is necessarily disconnected from the aerial and the ground during the period a message is being sent. ”

“ Wireless telegraphy, as it is practiced to-day, is based upon the fact that a system of wires or circuits, through which high frequency oscillations are surging, becomes a source of electromagnetic waves. Various methods have been devised for making the system more efficient and capable of giving better results with a given amount of power. ”

“ The receiving apparatus consisted of another antenna in circuit with a coherer and small battery for operating through a relay the ordinary telegraphic receiver. This apparatus contains the essential features of all the systems now in use. -- Wireless telephone, an apparatus or contrivance for wireless telephony. -- Wireless telephony, telephony without wires, usually employing electric waves of high frequency emitted from an oscillator or generator, as in wireless telegraphy. A telephone transmitter causes fluctuations in these waves, it being the fluctuations only which affect the receiver. ”

“ On the same day, when speech was being transmitted by the Bell apparatus at Arlington to the engineers and the French military officers at the Eiffel Tower in Paris, the telephone company’s representative at Pearl Harbor, Hawaii, together with an officer of the United States Navy, heard the words spoken from Arlington to Paris.
By Means of the Universal Bell System the Nation May be Promptly Organized for United Action in Any Great National Movement
It is believed that wireless telephony will form a most important adjunct and extension to the existing schemes of communication. ”

“ WIRELESS TELEGRAPHY AND TELEPHONY—PRINCIPLES AND APPARATUS Wireless telegraphy is probably the most remarkable and at the same time the most interesting of all the varied applications of electricity. The exceptional popular interest in wireless communication, as compared with most of the other daily tasks which electricity is called upon to perform, is easy to understand. ”

“ In summer the trees are full of sap and, being much better conductors of electricity when in this condition, act in the capacity of innumerable aerials rising in the air, and able to absorb appreciable amounts of energy. During these same months the air becomes highly ionized, in which state the air molecules carry an electric charge, and are particularly opaque to the waves. This condition also usually exists in the presence of sunlight, the result being that the most favorable time for the wireless transmission of messages are the hours around midnight. ”

“ The history of wireless telegraphy and telephony is a striking example of how it is possible for scientists laboring in the field of pure research and stimulated by accumulated knowledge and imagination to arrive at discoveries of the most vital importance. ”

“ It was not until the development of the 3-electrode thermionic tube had reached the stage of commercial production for wireless telegraphy purposes in 1913 that the problem of the telephone repeater could be solved. Since that time progress has been so rapid as to cause almost a complete revolution in long-distance telephony. ”

“ The form of the electrical waves is better preserved in free space, where there are no wires or where there is no magnetic matter. The difficulty in obtaining individual calls in wireless telegraphy resides in the present impossibility of obtaining sufficiently rapid and powerful electrical impulses, and a receiver which will properly respond to a definite number of such impulses.
The question of a relay seems as impossible of solution as it does in telephony. The character of speech depends upon numberless delicate inflections and harmonies. ”

“ No such trouble can occur with wireless telegraphy, and if it becomes necessary to move a wireless station with great rapidity, as for instance on an unexpected advance of the enemy, it is an advantage to have no wire to bother about. ”

“ As a result of exhaustive researches, too extensive to describe here, it has been ascertained that the function of the wireless telephone is not to do away with the use of wires, but rather to be employed in situations where wires are not available or practicable, such as between ship and ship, and ship and shore, and across large bodies of water. The ether is a universal conductor for wireless telephone and telegraph impulses and must be used in common by all who wish to employ those agencies of communication. ”

“ The whole principle of the wireless telephone is based on the fact that sound can be transformed into electricity and then can be transformed back into sound again. I know," he said, with a smile, "that that sounds very much like saying that you can make eggs into an omelet and then get the omelet back into separate eggs again"—here there was an audible snicker from the boys—"but that is very much like what is done by the wireless, although it doesn't exactly fit the case. ”

“ The practical success of wireless telegraphy depends on the use of an adequate medium for the transmission of electricity. The most meagre training suffices to prevent the declaration that if wireless messages cannot be sent without apparatus they cannot be sent at all. ”

“ A wireless telegraph transmitter is less costly than a wireless telephone transmitter and it is a very good scheme for you to learn to send and receive telegraphic messages.
At the present time, however, there are fifteen amateur receiving stations in the United States to every sending station, so you can see that the majority of wireless folks care more for listening in to the broadcasting of news and music than to sending out messages on their own account. The easiest way to begin wireless, then, is to put up an aerial and hook up a receiving set to it. ”

“ Many of those who had followed wireless telegraphy from its beginnings and knew somewhat of the theory of how it worked, set up a hue and a cry that the signals he had received were sent by ships at sea, or else they were due to static, as we call it now, that is, little charges of atmospheric electricity which accumulates on the aerial wire and finally discharges through the detector into the ground and this makes a click in the head-phones that sounds like a dot. ”

“ Here, in the depths, is woven that mysterious power that carries the wireless message through the rocks of the mountains and the channels of the sea, and wraps the earth in a diaphanous garb that makes the wireless telephone a possibility. ”

“ So when after Chapter V had been written Captain Morris found new and interesting information on the use of wireless telegraphy in aircraft in the days before the war, the whole of this difficult chapter had to be reopened for new patching. “In regard to wireless,” he wrote, “I am like a blind man who has never talked to painters employed to write a critique of a picture exhibition. It’s paralysing. The only escape is to keep on broad lines. Every one knows that wireless sends messages. ”

“ That is why any wireless receiving station, within a certain radius, can catch any messages that may be flying through the air--that is unless certain apparatus is tuned, or adjusted, to prevent this."
"Well, once the impulses, or electric currents, are sent out into space, all that is necessary to do is to break, or interrupt them at certain intervals, to make dots, dashes and spaces. These make corresponding clicks in the telephone receiver which the operator at the receiving station wears on his ear. ”