Marvels of Modern Science

-Principles of Wirel

ess Apparatus-Th

n for a considerable distance throughout the surrounding country. These primitive signals could be passed on from one point to another, until a large region could be covered and many people brought into communication with one another. These fires expressed a language of their own, which the observers could readily in

istricts especially on May Eve and the festival of mid-summer. On these occasions bonfires are lit on alm

d answer the purpose in daytime; hence signal towers were erected from which flags were waved and various devices displayed. Flags answered the purposes so very wel

eld tactics the heliograph or reflecting mirror which, ho

distance. Messages and all sorts of communications could be flashed over the wires in a few minutes and when

To the man who enabled us to talk to long distances without a wire at all it would seem we owe a still greater debt. But who is

ves which make it possible. However, it is to the men whose indefatigable labors and genius made the electric telegraph a reality, that we also owe wirele

and addressed her in the vernacular of Paradise in that famous sentence which translated in English reads both ways the same,-"Madam, I'm Adam." The oral wo

nd these so stimulate the hearing apparatus that a series of nerve impulses are conv

and which we call the ether. These vibrations can reach out to a great distance and are capable of so affecting a receiving apparatus

a series of ripples which grow fainter and fainter the farther they recede from the centre, the initial point of the disturbance,

produces a sound and sends a tremor out upon t

e or wavelet is the water. In the second case the medium which

and between molecules and atoms not otherwise occupied by gross matter. When a lamp is lit the light radiates from it in all directions in a wave motion. That which transmits the light, the medium, is ether. By this means energy is conveyed from the sun to the earth, an

If we wish to communicate to a great distance the ether must be disturbed in proportion to the distance. The vibrations that produce light are not sufficient in intensity to affect the ether in such a way that signals can be carried to a distance. Other disturbances, however, can be made in the ether, stronger than those which create light. If we charge a wire with an electric current and place a magnetic needle

ire with a brass knob at either end and bent around so as to form an almost complete circle leaving only a small air gap between the knobs. Each time there was a spark discharge from the induction coil, the experimenter found that a small electric spark also generated between

e any practical results from his wonderful discovery, to him in a large measure should be accorded the honor of blazoning the way for many of the intellectual giants who ca

nly in two ways: first by the actual transference of matter as when a stone is hurled from one place to another; second, by the propagation of energy from point to point through a medium which fills the space between two bodies. The body s

or instance, when one tuning fork responds to the vibrati

us at the sending station sends out waves of a certain period through the ether and these wav

n jar or oscillator system of an induction coil, but since that time these radiations have be

em but that this resistance was very materially reduced when electric waves fell upon the filings and remained so

ing that the filings cohere or cling together under the influence of the electric waves. Almost any metal will do for the

; a wire enters at each end and is attached to little blocks of metal which are se

wires and instead of the metal filings there is a globule of mercury between the plugs. When electric waves fal

tectors for the electrical waves. Nearly all have to serve the same purpose, viz.

s placed a paste made up of alcohol, tin filings and lead oxide. In its normal state the paste allows the battery current to get across from one block to another, but when electric waves touch it a chemical action is produced which immediately

the soft iron piece will keep changing their position at each half revolution. It requires a little time to effect this magnetic change which makes it appear as if a certain amount of resis

an electric current in a neighboring coil of wire. In this way we can detect the changes in

es from one pole to the other. This change takes place suddenly when the electric waves form the transmitting station, fall upon the receiving aerial conductor and are conducted round the moving wire, and as the band is passing through a coil of insulated w

he honor of several useful inventions and additions to wireless apparatus must be given him. He started experimenting as far back as 1895 when but a mere boy. In the beginning he employed the induction coil, Morse telegraph key, batteries, and vertical wire for the transmission of signals, and for their reception the usual filings coherer of nickel with a very small percentage of silver, a telegraph relay, batteries and a vertical wire. In the Marconi system of the prese

up and some one intercept the messages intended for another, but this is being overcome by the adoption of

practical purposes was for a good while looked upon with more or less suspicion. But as knowledge of wave motions developed and the laws of governing them were better understood, the receiver was "tuned" to re

the two metal spheres between which the electric charge takes place and is carried up into the air for a great height, while to the second sphere another wire is con

ed without any earth connection and radiated into space in all directions, rapidly losing force like the disappearing ripples on a pond, whereas th

ficient to produce the necessary ether disturbance, but when a greater distance is to b

in the form of intermittent sparks, but is a true alternating current,

has saved so many lives at sea that its installation is no longer regarded as a scientific luxury but a practical necessity on every passenger vessel. Practically every steamer in American waters is equipped with a wireless station. Even freight boats and tugs are up-to-date in

ther items of interest are regularly transmitted to ships at sea. Captains keep in touch with one another and with the home office; wrecks, derelicts and storms are reported. Every operator sends out regular reports d

. Fogs, rains, torrents, tempests, snowstorms, winds, thunder, lightning or any aerial disturbance whatso

t was in 1898 that Marconi made his first remarkable success in sending messages from England to France. The English station was at South Foreland and the French near Boulogne.

his first apparatus that he was able to send out waves

ween the Isle of Wight and the Lizard in

penetrate the ether in order to generate stronger electrical waves. Oil and steam engines and other appliances were called into use to create high frequency currents and thos

signal. The letter S, which in the Morse code consists of three successive dots, was chosen. Marconi feverishly awaited results. True enough on the day and at the time agreed upon the three dots were clicked off, the first signal from Europe to the American continent. Marconi with much difficulty set up other aer

icient power transatlantic wireless could be successfully carr

Nova Scotia, Marconi sent the first message by wire

he electric waves conveying this message traveled 3,000 miles over the Atlantic following round an arc of forty-five

ty but an accomplishment, though as yet the system has not been put on a general business basis. [Footnote: As we go to press a new record has been established in wireless transmission. Marconi, in the Argentine Republic, near Buenos Ayres, has re