WHAT IS ELECTRICITY?

Evening Star, Issue 17927, 24 March 1922, Page 6

WHAT IS ELECTRICITY?

PROFESSOR FLEMING- ON

ELECTRONS,

“What is electricity '!" The answer to ,i iliis question was the theino of a lecture by Professor .1, A. Fleming at tho Royal Institution recently. An electric current reduced to first principles is, according to Professor Fleming, a. drift of tho movement of electrons. To enable his audience to grasp some idea of electrons—■which, he eaid, were of two kinds, positive and negative —ho noted' them to imagine first the smallest piece ot gold that maid .possibly bo seen under a good microscope. That piece of gold would bo about the' 100,000 th part of an inch. It it could be divided up still further into about :, 2,000 pieces,' these would bo atoms. _An atom, in fact, was hardly discernible in a 'good microscope. •Electrons' wore still further lost m tho ilepths of invisibility. They were each : ... about the 100,000th’ part of an atom. "They are as much smaller than an atom/’ said Professor Fleming, “as a .particle of dust just seen under a good microscope is smaller than a golf ball. It is now generally considered! that a chemical atom is in' structure - something like a solar system. In the centre is a ; nucleus built *no of positive _ electricity, ■ or electrons, and round it circulate, _in I : rings, a number of negative electrons, like ; t planets.” These electrons moved about in a piece of copper wire, for instance,_ at the rate of sixty miles a socond—a kind ! of gas contained in the metal—and an IK. electric current consisted of electrons p; moving, not to and li-o, as was their i/Vl "nature, but in, tho same direction. It was p 'Faraday’s invention of the induction _ coil i'i ; i-»great lengths of wire wound in a circle i , i —coupled with tho method of creating /i;/; electric oscillations by discharges of a I/'/: 1 " Leyden jar, that led to the electrons y; /bemg made to run forward. From that /.//moment electricity was harnessed to the //‘/service of mankind. *■ -