Word Finder - telegraphy

definition

Communication at a distance by means of the telegraph, either over wires or by wireless telegraphy, usually using Morse code

definition

The apparatus and techniques used in such a system

Braun also gave an interesting solution of the problem of directive telegraphy.'

For his connexion with the growth of telegraphy, see Nature, xi.

He not only guided the growth of scientific telegraphy on land wires, but made the earliest experiments with submarine cables, foreseeing the practicability of this means of communication as early as 1840.

Aluminium conductors have been employed on heavy work in many places, and for telegraphy and telephony they are in frequent demand and give perfect satisfaction.

In 1873 he was appointed professor of physics and telegraphy at the Imperial College of Engineering, Tokio.

For the purposes of wireless telegraphy, when large condensers are required, the ordinary Leyden jar occupies too much space in comparison with its electrical capacity, and hence the best form of con denser consists of a number of sheets of crown glass, each partly coated on both sides with tin foil.

Fessenden in wireless telegraphy, and they form a very excellent arrangement for standard condensers with which to compare the capacity of other Leyden jars.

The principles of telegraphy (land, submarine and wireless) and of telephony are discussed in the articles Telegraph and Telephone, and various electrical instruments are treated in separate articles such as Amperemeter; Electrometer; Galvanometer; Voltmeter; Wheatstone'S Bridge; Potentiometer; Meter, Electric; Electrophorus; Leyden Jar; &C.

Turning to practical applications of electricity, we may note that electric telegraphy took its rise in 1820, beginning with a suggestion of Ampere immediately after Oersted's discovery.

By this simple device he provided a means of measuring small electric currents far in advance of anything yet accomplished, and this instrument proved not only most useful in pure scientific researches, but at the same time was of the utmost value in connexion with submarine telegraphy.

Fitzgerald was the first to attempt to measure the length of electric waves; Helmholtz put the problem into the hands of his favourite pupil, Heinrich Hertz, and the latter finally gave an experimental demonstration of electromagnetic waves, the "Hertzian waves," on which wireless telegraphy depends, and the velocity of which is the same as that of light.

He was specially noted for his discovery of the electrical conductivity of bismuth and other metals, and for his pioneer work in wireless telegraphy.

In the later years of his life he was engaged in developing a system of multiplex telegraphy.

Submarisie telegraphy, which had done so much to knit the empire together, was not perfected for many years afterwards; and long ocean cables were almost entirely constructed in the last half of the reign.

Although his contributions to thermodynamics may properly be regarded as his most important scientific work, it is in the field of electricity, especially in its application to submarine telegraphy, that Lord Kelvin is best known to the world at large.

Some held that if this were true ocean telegraphy would be impossible, and sought in consequence to disprove Thomson's conclusion.

The mirror galvanometer and the siphon recorder, which was patented in 1867, were the outcome of these researches; but the scientific value of the mirror galvanometer is independent of its use in telegraphy, and the siphon recorder is the direct precursor of one form of galvanometer (d'Arsonval's) now commonly used in electrical laboratories.

Thomson's work in connexion with telegraphy led to the production in rapid succession of instruments adapted to the requirements of the time for the measurement of every electrical quantity, and when electric lighting came to the front a new set of instruments was produced to meet the needs of the electrical engineer.

Hertz and of wireless telegraphy were investigated by him in 1853.

In 1866, perhaps chiefly in acknowledgment of his services to transAtlantic telegraphy, Thomson received the honour of knighthood, and in 1892 he was raised to the peerage with the title of Baron Kelvin of Largs.

He also carried on extensive researches in the theory of magnetism; and it is interesting that in connexion with his observations in terrestrial magnetism he not only employed an early form of mirror galvanometer, but also, about 1833, devised a system of electromagnetic telegraphy, by which a distance of some 9000 ft.

Such equipment is defined as ' non-wireless telegraphy apparatus ' and is beyond the scope of these guidelines.

Telegraphy The first message or ' telegram ' sent by a telegraph using electromagnetism was in 1833.

In 1876, Heaviside took account of self inductance, obtaining the equation of damped harmonic motion known as Heaviside's Equation of Telegraphy.

Thanks to wireless telegraphy, 712 people were saved.

In learning telegraphy, progress is rapid for a few weeks and then follow many weeks of less rapid improvement.

My research has revealed his involvement in electric telegraphy from 1848 when he assisted Sir William Fothergill Cooke.

If you would like to know more about early telegraphy, take a look at C&W's history site.

Under the Wireless telegraphy Act 1949, the use of wireless telegraphy equipment in the UK must be licensed unless it is specifically exempt.

The young inventor, who was born in Italy 24 years ago, has been experimenting with wireless telegraphy for the last four years.

Another section is devoted to the use of radio telegraphy on board deep-sea trawlers.

In their youth, the Epeirae, who are then very wide-awake, know nothing of the art of telegraphy.

From this time he was in constant request in connexion with submarine telegraphy, and he became known also as an inventor.

Since the time of these early experiments, various other modes of detecting the existence of electric waves have been found out in addition to the spark-gap which he first employed, and the results of his observations, the earliest interest of which was simply that they afforded a confirmation of an abstruse mathematical theory, have been applied to the practical purposes of signalling over considerable distances (see Telegraphy, Wireless).

Mr Scudamore, who was regarded as the author of the bill for the acquisition of the telegraph systems, reported that the charges made by the telegraph companies were too high and tended to check the growth of telegraphy; that there were frequent delays of messages; that many important districts were unprovided with facilities; that in many places the telegraph office was inconveniently remote from the centre of business and was open for too small a portion of the day;' that little or no improvement could be expected so long as the working of the telegraphs was conducted by commercial companies striving chiefly to earn a dividend and engaged in wasteful competition with each other; that the growth of telegraphy had been greatly stimulated in Belgium and Switzerland by the annexation of the telegraphs to the Post Offices of those countries and the consequent adoption of a low scale of charges; that in Great Britain like results would follow the adoption of like means, and that the association of the telegraphs with the Post Office would produce great advantage to the public and ultimately a large revenue to the state.

It had to extend the hours of business at all the offices; it had to extend the wires from railway stations lying outside of town populations to post offices in the centre of those populations and throughout their suburbs; it had also to extend the wires from towns into rural districts previously devoid of telegraphic communication; it had to effect a complete severance of commercial and domestic telegraphy from that of mere railway traffic, and in order to effect this severance it had to provide the railways with some 6000 m.

The monopoly conferred upon the Postmaster-General by the Telegraph Act 1869 was subsequently extended to telephony and wireless telegraphy, but it does not extend to submarine telegraphy.

Such an arrangement would distribute a 1 For a history of the discovery of the earth return, see Fahie, History of Electric Telegraphy to the Year 18 37, pp. 343-348.

A very ingenious call-bell arrangement was devised, capable of responding only to regularly reversed battery currents, but not 1 See Fahie, History of Wireless Telegraphy, p. 170; also 5th Report (1897) of the Royal Commission on Electrical Communication with Lightships and Lighthouses.

Marconi's system of electric wave telegraphy consists therefore in setting up at the transmitting station the devices just described for sending out groups of damped electric waves of the above kind in long or short trains corresponding to the dash or dot signals of the Morse alphabet.

The problem of syntonic electric wave telegraphy is then to construct a transmitter and a receiver of such kind that the receiver will be affected by the waves emitted by the corresponding or syntonic transmitter, but not by waves of any other wavelength or by irregular electric impulses due to atmospheric electricity.

Nevertheless, transoceanic wireless telegraphy over long distances, such as those across the Atlantic and Pacific oceans, is a matter to be reckoned with in the future, but it remains to be seen whether the present means are sufficient to render possible communication to the antipodes.

Leyden jars are now much employed for the production of the high frequency electric currents used in wireless telegraphy (see Telegraphy, Wireless).

Metallic selenium is a conductor of electricity, and its conductivity is increased by light; this property has been utilized in apparatus for transmitting photographs by telegraphy (see Telegraph).

By wireless telegraphy she sent out signals of distress, and several liners were near enough to catch and respond to the call.

If you would like to know more about early telegraphy, take a look at C&W 's history site.

However, Section 10 of the 1949 Act provides for regulation of non-wireless telegraphy apparatus which causes undue interference to authorized radio services.

The intention is to permit the use of such devices without the need to hold a Wireless Telegraphy license.

A consultation document on the proposal to impose fixed penalty notices for summary wireless telegraphy act 1949 offenses.

Under the Wireless Telegraphy Act 1949, the use of wireless telegraphy equipment in the UK must be licensed unless it is specifically exempt.