A-GREAT SCIENTIST

Evening Post, Volume CVIII, Issue 82, 3 October 1929, Page 27

A-GREAT SCIENTIST

FARADAY'S -DISCOVERIES

ELECTRICAL" INDUCTION

Arrangements are being made by the Eoyal Institution of Great Britain, in conjunction with the Koyal Society and the British Association, to celebrate, in September, 1931, the centenary" of the discovery of electro-magnetic induction by: the English chemist and psysicist, Michael Faraday, says an exchange. The conclusions reached by Faraday, consequent upon his famous researches, Jaid the foundation for all subsequent electrical inventions.

- .Although the existence of electricity was vaguely known as early as 600 '8.C., the first electric current was not produced until 1799. Faraday's discovery in 1831 gave the first great impetus to^ electrical research. After laborious experiments he discovered the induction of electric currents and the creation of currents by the motion of conductors in-magnet fields which initiated the era of modern electro-technics. After ten days of brilliant investigation he established, in short, the fact that a current may be induce- in a conducting circuit simply by the variation in a magnetic field, the lines of force of Trhich are linked with that circuit.

Faraday was born at Newington, Surrey, 'on 22nd September, 1791. ; His father was-a blacksmith, and Faraday was apprenticed to a bookbinder at an early age.' At the age of 21 he heard four lectures by Sir Humphrey Davy, and from that time he formed a strong desire to probe into the secrets of Mature. After his appointment as assistant at the laboratory of the Eoyal Institution in 1813, and a tour through Europe with Davy, he became director or the laboratory in 1825. In 1833 he was appointed Fullerton professor at the iiißtitntion for life, without the obligation to deliver lectures. He was at the institution for 54 years and died at Hampton Court on 25th August, 1867.

'Faraday's earliost chemical work was iii-tho paths opened by Davy, to whom ha acted as assistant. He made a special study of chlorine and discovered two new chlorides of carbon. He also made the first rough experiments on the diffusion of gases, a phenomenon first pointed out by John Dalton. He succeeded in liquifying several gases; he, investigated the alloys of steel and produced several new.kinds of glass intended for optical purposes. A specimen of one of these heavy glasses later became historically important as the substance in which' Faraday detected the rotation of the plane of polarisation of light when the glass was placed in a magnetic field.

'"-Important as it was Faraday's chemiealt work was soon completely overshadowed by his electrical discoveries. His first notable discovery was the production of the continuous rotation of magnets and of wires conducting the electric current round each other. Thia Jed: him to discover the method of producing the continuous rotation of the wire round the magnet and of the magnet round the wire. Althongh the tangential force between, an electric current and a magnetic pole was clearly apprehended by some scientists at the time, the realisation of the continuous rotation of. the wire and the magnet, round each other was a scientific puzzle requiring no mean ingenuity for its original solution.

. One the one hand the electric current always forms a closed circuit and on the other the two poles of tho magnet have equal but opposite properties and are inseparably connected, so that whatever tendency there is for one pole" to circulate round the current in one. direction is opposed by the tendency of the other pole to go round tbo other ■way. Thns the one pole can neither drag the other round the wire nor leave it behind. This can only be done^by adopting Faraday's ingenious solution by causing the current in some part of its course to divide into two iehannels, one on'each side of,the magnet, so that, the middle of the magnet can pass across the current without stopping it. .

Faraday's crowning discovery of elec-tro-magnetic induction was made in September, 1831. He made several unsuccessful attempts to obtain an electric current by means' of a magnet and to produce a current in ono wiro by moans of p. current in another wire. He persevered and at last he obtained evidence that'an electric current can induce another in a different circuit.

Dnring his first period of discovory Faraday also established the identity of the electrification produced in different ways, the law of the definite electrolytic action of the .current; and also tho fact, upon which he laid great stress, that every unit of positive electrification is related in a definite manner to a unit of negative electrification. ■ He found .■ait it waa impossible io produce an "absolute charge of electricity" of one kind not related to an equal charge of ■B opposite kind. He also discovered the difference of the capacities of different substances for taking part in electric induction. In 1841 he realised he wanted rest, and it was not until 1345 that he entered upon his .second great period of research in which he discovered the effect of magnetism on polarised light and the phenomena of diamagnetism. ' • ' ■ .

■■', Faraday's work provides a supreme iexample of concentration in his efforts to identify the apparently different forces of Nature, of far-sightedness in selecting subjects for investigations, and of energy in the working out of his discoveries.

5 When at length he found his memory failing and his mental powers declining he gave np without ostentation or complaint whatever parts of his work he could no longer carry on according to his own standards of efficiency. When he was no longer able to apply his mind to science he remained content arid happy in the exercise of those kindly feelings and warm affections which he had cultivated no less careffllJy than his scientific powers.