MARVELLOUS ELECTRON

Radio Record, Volume I, Issue 12, 7 October 1927, Page 5

MARVELLOUS ELECTRON

ia MINUTE BUT POWERFUL Most people are familiar with some of the common facts of electricity. For exaniple, perhaps you have noticed the | peculiar behaviour of the hair when combed with a hard rubber comb, and have heard, if not seen, tlie tiny sparks of electricity that pass between the two. This is fundamentally identical with the electricity which heats the filements in your valves. Ifach is made up of the same kind of electric particles, or electrous as they are called, and the difference in the: two cases is much the same as tiie difference between a. raindrop sand a_ river, Both are made up of the same kind of molecules, but they manifest the energy tied up in them differently. In the same way all electrical phenomena are caused by the movements of electrous though the different phenomena may appear quite unrelated. Smallest Electric Unit, The electron is the smallest unit of. electricity. With one exception it is the only thing in nature that cannot be broken up into smaller parts. We do uot know absolutely its size and shape, but it is generally assumed to be a sphere of such size that if enough of them were laid in a row to make a line as long as the diameter of one of the hairs of your head, it would require more than seventy thousand million of them, Can Be Measured, In spite of the minuteness of the electrons, which is really far Leyond the limit of human comprehension, the quantity of electricity associated with it has been measured so accurately that the error cannot be greater than about one part in four thousand--less than four hundredths of 1 per cent. ‘This charge of the electron is, like its size, so small that a figure representing its magnitude is quite meaningless. Some

idea, however, may be grasped by computing the number of electrons which fare equivalent, in quantity of electricity, to that which flows through an ordinary 40-watt lamp in one second. ‘This is found to be about two and a half quintillions-25 with 17 ciphers after it. This number is so enormous that if all the people on the earth~and there are about two billions of them-were put to the task of counting this number, and each man, woman and child counted at the rate of one electron per second for ten hours every day, it would take over seventy-five years to finish the job. ‘This is the number of electrons flowing through the filament of a 40watt lamp in a single second. Movement of Electrons. So much for the electron itself. We shall now consider its connections with the filament in a radio valve. It is now known that every atom of every cleinent is made up partly of electrons and that, at least in metals, there are, in addition to the electrons tied up with cach atom, other electrons which are free to move abont. These "free" clectrons, whether in a metal or outside in space always move toward a positively charged body and are'repelled by a negatively charged one, A current of electricity in a wire is nothing more than the movement of these ‘free" electrons in the direction of a positive charge, Electronic Emission. About thirty-four years ago Sir J. J. Thonison discovered that, although electrons could not be drawn out into space from a cold body by the attraction of a_ positive charge, electrons could be drawn out from a filament when it was heated. ‘This opened the door to the interesting field of thermionics, the emission of electrons from hot bodies, and a great deal of work has since been done by other physicists in determining the laws governing this phenomenon. It has been found that the emission of electrons from heated metals is quite analogeus: to the emission of vapours from heated liquids. ‘The tate of evapoiation from liquids is known to increase very rapidly as the temperature is raised and the same general law has been found to apply in the’ ‘ase of the "evaporation," if we may call it such, of electrons from hot bodies,

MASONIC SERVICE, After our announcement appeared last week regarding the broadcasting of the Masonic Church service from the Wellington Pro-Cathedral, it was found impossible for the arrangement to be carried out. SOHO eer eer eri iiiit