Cathode ray wonders
Professor Sanford explains Crooke’s Tubes, ether vibrations and X-rays
Waves with a new wiggle
The great thing that Röntgen’s discovery may be, and things that it is not
Professor Fernando Sanford of the department of physics of the Stanford University has just received a letter from his associate, Professor Carmen, who is now in Berlin, and who has investigated Röntgen’s photographs with his X, or unknown, rays. Professor Carmen doesn’t say very much, but what he does say comes from a scientist.
“I saw Röntgen’s photographs the other day,” writes Carmen in the course of his letter, “and heard Warburg, professor of physics in the University of Berlin, and others discuss them. Lummer had also seen them, and there seems to be no doubt about the reality of the phenomenon.
“The photograph of the hand, in which only the bones and the ring are shown, is very striking. It is, however, not very sharp. A photograph of a magnetic compass in a wooden case, photographed through the case, is very sharp indeed. We know as much here as any, where, but there is yet no consensus of opinion as to what the phenomenon really is. The natural idea is that they are longitudinal ether waves. They are, however, very faint.”
Photographs in the dark
Professor Sanford is a widely-known physicist, who has made some important discoveries in physical science, the most important of which were his photographs in the dark, with the so-called Hertzian waves, made three years ago, and he is naturally keenly interested in Professor Roentgen’s startling discovery of unseen shadows, not made with light, and of a way to fix them on photographic plates. Sanford has experimented a little with Roentgen’s process, and has secured faint results, but he has not had ready for use the proper apparatus, and is not ready to talk about his experiments.
He talked about Roentgen’s work, how ever, yesterday, at the university, and explained, in a way that people of ordinary intelligence can understand, what Roentgen’s discovery may possibly be. The scientists are only guessing at the new thing yet, though many have opinions.
“The point of chief scientific interest in the matter, which is the theory by which Roentgen and others explain the phenomenon, the papers say little or nothing about,” said Professor Sanford. “That is, that he has discovered a new form of motion or vibration in the ether – vibrations that are longitudinal instead of transverse to the line of progress. I would not express any definite opinion about it. It would be only guessing, and there is plenty of guessing going on. It is a scientist’s business to guess, but to find out before he talks. A large part of the stuff and most of the pictures the papers publish are necessarily fakes. It is but natural that there should be a good deal of slopping over about such a thing, of course. It is too early to make any definite predictions as to what scientific or practical value the discovery will have, but it is, of course, a thing of great interest to physicists, and it may extend our knowledge wonderfully.”
Then the physicist led the way into a big laboratory, full of all sorts of costly scientific apparatus, and elucidated somewhat the story of Roentgen’s X-rays.
The discovery and the process of Professor Roentgen [Röntgen] (call it Rantgen, with a short “a” and a hard “g”) began with a Crooke’s tube, and the professor picked up a Crooke’s tube and connected it by two wires with an induction coil, which was in turn connected with a two-cell battery. A Crooke’s tube arranged for use is a hollow sealed shell of glass of any size or shape, from which the air has been very nearly but not quite exhausted, and into which run platinum wires connected with the opposite poles of a battery.
The bulb of an incandescent electric light is a pretty good Crooke’s tube. The one that Professor Sanford picked up was made to show extra effects. It was of two compartments — one a small one — between which there was free connection through a slender glass tube bent double and then into the form of a cross. Air or fluid passing between the compartments would go up, around and back through the cross. The professor set the current at work and instantly the Crooke’s tube became a thing of beauty. Around one of the wire ends at one end of the tube, there appeared a purple glow that was simply a mass of fluorescence in the vacuum. The wire itself gave out no light. At the other end of the tube was a much smaller fluorescence. The glass cross glowed with a beautiful greenish light, which seemed to stream through the cross but not leave it.
Now, this Crooke’s tube, as it lay there glowing with its strange light, was ready to produce one of Roentgen’s photographs if things had been fixed right around it. Vibrations of some sort — those X rays — were surely beaming from it in all directions, shining through the box on which the tube lay, as sunlight would shine through a glass case, and if the reporter had possessed a sense capable of perceiving those rays he might have seen before him the skeleton of the professor of physics as one might see iron or wooden bones in a glass manikin when the white sunlight shone through it.
An accidental discovery
But now don’t think that this pretty light, the vibrations that the human eye is capable of perceiving, would have anything to do with the Roentgen photograph. Scientists would have said so, until Roentgen accidentally discovered something the other day — that arrangement of battery, induction coil and vacuum was setting up different kinds of vibratory motions that variously rolled out through the surrounding ether, air and solid substances, as a big turbine wheel, for instance, might cause all sorts of heavy and light, slow and rapid, shakings through the water and the mill. If that arrangement had been set up before a scientist a few centuries ago the only phenomenon he would have perceived would have been the glow of light, because the particular vibrations producing it are the only ones of the lot that man happens to have a sense to perceive.
Since a century and more ago when man learned by experiment to recognize the electric current by its effect on something besides sense, the ordinary force of the electric current would have been recognized in that simple arrangement of Professor Sanford’s.
That makes two things that would have been the limit of the forces of nature which man would have perceived that arrangement on the laboratory table setting into activity up to a very few years ago. Then Hertz found a new sort of vibrations proceeding from an induction coil and especially from the neighborhood of an electric discharge and these are now called Hertzian waves. They are not light, heat, or the electric current. They are vibrations that flow outward from their source like light from a thing that glows, and until Hertz stumbled on them so recently nobody ever dreamed that such things were bustling about in the universe.