MR. POYNTON’S LECTURE.

Manawatu Herald, Volume XXXVIII, Issue 1515, 26 February 1916, Page 4

MR. POYNTON’S LECTURE.

Mr]. W. Poynton, S.M., delivered a very interesting lecture in the State school on Thursday evening, on “Light.” Mr Hornblow occupied tbe chair. The attendance was not as satisfactory as was anticipated, due to counter attractions. Mr Poynton kept the close attention of tl»e audience throughout, and kept away from difficult technical terms. Several diagrams assisted the audience to get a clear grasp of the lecture. The following is a summary of Mr Poynton’s lecture : The reason we hear is because the air between the bell or gun, or whatever sounds, and our ears 'has been disturbed. The movement reaching our ears is conveyed to tbe brain along certain nerves, and we then recognise it as sound’. The difference between noise and musical tones consists in regular repetitions; an explosion or thunderclap gave one big movement, but a bell or flute sounding gives a succession of these movements at regular intervals. Shrill or high notes are due to a greater number of these regular teraors than bass or low notes. If a card is placed against a revolving cogwheel, and is struck by the cogs at the rate of about 500 times a second, we would get a humming tone of a pitch given by tbe keys in the centre of a piano ; if the wheel were turned faster the pitch would rise, if slower .it would become deeper. The keys at the extreme right hand end of the piano gave about 4,000 waves in the air per second, and those at the bass end about 60 per second. The human ear can not discern more than 30.000 vibrations per second, nor less than 30 as musical notes. There are certainly notes of hundreds of thousands of sound waves per second, but we do not hear them, probably insects do. It takes sound waves some time to move in the air. If a gun is fired on a dark night a mile away, we would see the flash five seconds before we heard the report. If a cannon were fired from Calais to Dover, the flash would be seen from England more than a minute before the sound reached there. Just as sound was due to the movements of the air, so light was caused by the motion of another substance which reached from the earth to the sun and the remotest stars. We see because these tremors reach our brain through our eye nerves. Just as musical pitch is due to the number of air waves striking our ears per second, so colour was due to the rapidity of ether waves. The white light from the sun, or a lamp, was composed of all sorts of wave-lengths mixed together. When this light fell on a bed of flowers some of these waves were absorbed by the flowers and others rejected, or reflected, from the flowers, and so reached our eyes. If they were long, like the bass notes of the piano, we see red, if short we see blue flowers, and if half way between red and blue we see green colours. But the ether waves were very small. Along a beam of light the red waves would measure 33,000 to the inch, the green 50,000, and the violet 60,000. Light travelled at an inconceivable velocity—--187.000 miles a second. In one second it Would pass more than seven times round the earth. In every inch of that stream there would be that number of waves, so that the wonderful phenomena of light was due to millions of millions of vibrations per second in the mysterious thing that filled the whole universe. Other forces such as heat, electricity, gravitation, magnetism,, are due to movements therein, but we could not see or hear them. The best way to grssp the subject was to imagine ourselves in a dark room with a fan-like arrangement in one corner, capable of moving and increasing its beats indefinitely. We would not be aware of its presence until it moved 30 times a second. We would then hear a deep hum. As it increased in speed all the musical notes of the scale would

be sounded in succession, and when it came to the other limit of our hearing we would hear a shrill thin shriek. After that there would be silence. No matter how last it moved we would hear no more. When it had reached thousands of millions of millions of beats per second we would feel heat. Heat is a slower movement of ether than light. Faster and faster it would move, and we would after a time perceive a dull red glow. Faster still, we would see orange, then yellow, then green, then blue, indigo and violet; after that, darkness. Our eyes, like our ears, have their limitations. No matter what happened, we would see no more. But we know that vibrations continue. Faster than light rays we have a whole world of power — X-rays and others —but we cannot see them. This extraordinary thing, ether, contains the marvellous property of giving all forces simply by moving in a different way. One movement gives electricity, a faster one beat, a still faster one light; a different one still K-rays, and so on. If we had no eyes we would not know anything about light. But it would be a force of nature all the same ; and there are many forces about which we know nothing at present, but it is certain we will some day control them like heat and electricity have been made to enter our services. In man’s early history he did not know the use of fire. It would occur occasionally by lightning flashes or through volcanic eruptions, and must have been a terror and a curse tp him. He would not know then, or even speculate, that his descendants would one day be able to produce it at will, mould the hardest substance through it, create new and useful things through its agency, make it so subservient that it would convey as many as the most numerous tribes then existing across the land faster than the fleetest animal could run, or across the ocean more rapidly than any (fish can swim, or enable him to ascend into the air as high as the eagle soared, and outdiscance it in speed, or kill the largest animal at a distance of a day’s journey. But all this has come to pass through getting control of one force. Look at our express trains, ocean liners, flying machines, and 15-inch guns. Until about 150 years ago nothing was known about electricity except that a piece of amber, sealing wax,, or silk, when rubbed attracted light bodies or gave a feeble spark. Like the control of the force of heat, so harnessing electric force has been astounding in its results ; the telegraph, the telephone, dynamo, wireless telegraphy; Xrays, electric light and many other uses are now due to this force, Although man has eyes, he’only recently controlled the force which has always enabled him to see. The ancients knew of the burningglass or lens, which was simply a circular piece of glass or crystal

thicker in the centre than at the circumference. It bent the rays of light to a centre. The eye placed at this spot saw more of the object giving off the light and so magnified it. But until Galileo’s time this was not developed. These lenses were the foundation of telescopes which enlarged man’s vision regarding the solar and stellar universes, and of microscopes, giving him a knowledge of smaller things and the power to suppress diseases which is almost godlike in its beneficence to his race; also photography and moving pictures. There are many other forces in nature awaiting our exploration. Take nerVe force. It is not heat or electricity. We know a lew facts about it—as much or more than our ancestors did about electricity or heat. We know its rate of motion along a nerve—that it does not set up induced currents in parallel nerves as electrified wires do in neighbouring wires. Some day we may be able to gather it in batteries and then it is stagg*ering to think what we may do —restore a lost limb, stimulate growth, prolong life for centuries. Telepathy is a part. Whatever the force It gave great promise, when understood and controlled, of marvellous results. The lecturer here gave instances of his personal experiences and referred to remarkable results obtained in England and France. When under control this force may

enable man to communicate without wire to anyone else wherever situated, discover crimes and prevent accidents. The homing instinct of birds and animals was a promising field of study. What strange force guided the kuaka or New Zealand godwit, which annually flew at a certain time, almost to the day, from the north of this island to Siberia to lay its eggs there, and enabled it to return —a flight of 7000 miles each way. The answer “instinct” was not an explanation. In the case of the godwit it might be said that going and coming with the flocks the younger birds learned from the old, but that did not explain the flights to New Guinea and New Caledonia of the two cuckoos, which visited New Zealand, These were hatched here not by other cuckoos but by New Zealand birds which never left our shores. At a certain time these solitary birds took their flight across the opean as if they had a compass and chart before them. Although they did not fly as far as the kuaka their performance was amazing. The enormous apparent gaps that exists in th,e scale in etheric movements are not real but due to bur limited senses. The whole universe is throbbing with forces unknown to or dimly realised by us, but they will in the future be mastered by us. Gravitation may probably be neutralised and then with a battery of some sort we may be able to raise from the earth at will. It is a certainty that beat will be changed direct into electricity and the dreadful waste of energy now going on in all our machinery will be saved. When a housewife boils a gallon of water she generates enough force to raise 500 tons or three or four ordinary houses more than one foot from the ground. The whole subject of the ether was a most fascinating one and full of promise for the human race. At the conclusion a number of questions were asked and further points elaborated. On the motion of Dr. Mandl, seconded by Mr R. Moore, the lecturer was accorded a very hearty vote of thanks and the wish expressed that a further opportunity should be afforded the public of hearing Mr Poynton on other subjects.