These must have been great days for the students at Madison, while Wood’s introduction of excitement, dramatics, and circus technique was beginning to attract world-wide attention both to him and the university. He had been from earliest childhood, and still is today, a circus man, a showman — just as were Archimedes, Galileo, and Copernicus. He is full of childish vanity, God knows, and dearly loves the limelight and applause — but the excitement is more in the thing shown than in himself, so that while he sometimes seems to be an egotist and exhibitionist, he is not actually one in the unpleasant connotation of the words. This distinction was keenly sensed by Professor Benjamin Snow, then head of the Department of Physics at Madison. A new young instructor, or assistant professor as he presently became, was and still is small potatoes in any major university, and if Wood had not been encouraged by this important ally higher up in the faculty — if there’d been an academic stuffed shirt at the head of the department — he could scarcely have obtained the necessary cooperation. Luckily, Snow himself was a dynamic, enthusiastic lecturer and fond of spectacular stunts. The fun Snow and his young instructor had together is recorded in Wood’s notes.
He made me his assistant in the course on general physics for the sophomores. My duties at first were those of the uniformed darky who passes things to the conjurer as required. He was never satisfied with any piece of apparatus that was not the largest in the world, and I made a hit at once by constructing an enormous box for making smoke rings a foot in diameter, similar to the one I had made for my lecture in Chicago, when I was a student in chemistry. A dynamic smoke ring that would knock a large pasteboard box at the further end of the lecture table onto the floor delighted him beyond measure. It was also a new idea to him that smoke was not necessary for the formation of the ring, at all events it had never occurred to him that an invisible ring of air knocking things about was the more spectacular demonstration. Interested for the moment in these whirling vortices, I fussed around and concocted a number of new experiments with the rings, which were described and illustrated with photographs again, this time in the London Nature, including a method of making a ring one half pure air and the other half charged with smoke, so that it left the tube from which it was blown in the form of a U.
This can be done with a pasteboard mailing tube an inch or so in diameter by blowing dense smoke very gently along the bottom of the tube, held horizontally, so that the smoke flows along the bottom of the tube to the other end; then a gentle puff is given, and the half ring emerges. Another device made it possible to form a fat air ring, like a doughnut, with a white thread of smoke as a core, spinning with terrific velocity. This illustrated the very high velocity of rotation along the core of the vortex ring, or on the axis of a tornado. Illustrating the difference between force and work, the latter being defined as a force moving against a resistance through a finite distance, Snow was in the habit of leaning against the end of the lecture table and pushing against it with all his might. “I push, and I push, and I PUSH!”… Getting red in the face, perspiration breaking out on his brow… “There is no motion, I push and push, and I don’t do a particle of work!”… almost collapsing from his herculean efforts.
In one of his lectures I caught him in a slight mistake and being unfamiliar with the rule that “little assistants should be seen but not heard” called his attention to it at the close of the lecture.
His subject was gravitation, and he reminded the class of Jules Verne’s story of a journey to the moon, saying that the author never made a mistake or violated any laws of physics in his fiction.
“You will remember”, he said, “that when the projectile crossed the center of gravity between the earth and the moon, the passengers inside weighed nothing, but floated about without any support, and that, gentlemen, is just what would happen”.
At the end of the lecture, while some of the students were hanging around asking questions and inspecting the apparatus, I ventured the remark that in that particular case Jules Verne had certainly made a mistake; the passengers would float about as soon as the projectile was out of the earth’s atmosphere, for gravitational effects are not felt inside a freely falling or freely rising container. “I think we can prove it by experiment, by putting a half dollar on this book and tossing it up before the window. I think that daylight will be visible between the coin and book throughout its flight”, which was exactly what happened after two or three trials. This convinced Snow that Jules Verne was wrong, in this instance at least.
All these classroom discoveries and demonstrations were of interest, perhaps, only to students and scientists — but our young instructor soon followed them up with a “practical” invention which immediately obtained for the university a gift from the state of $200,000 and saves the world each winter millions of dollars in losses by fires resulting from the crude methods employed by plumbers. It was the now universally known Electric Thaw.
Since my own knowledge of what to do when my pipes freeze underground is confined to a number in the Rhinebeck Village telephone book which brings “Cart” Sipperley humming out with a service wagon full of precisely the gadgets Wood adapted forty years ago in Madison, and since all I understand about those coiled, imposing gadgets is that they unfreeze my pipes without the need of tearing up my floors and driveways, I’ve persuaded our Promethean Wood to dictate his own version of how he invented the Electric Thaw, and how it does the thawing. “You can brag a little, if you want to”, I told him, and he said with a hurt expression, “You know I never brag”.
The unprecedented cold (he dictated) throughout the whole Northwest in the winter of 1899 froze the ground in Madison down to a depth of eight feet and more. Half the service pipes in Madison were frozen and there was some fear that the mains had ceased functioning. Bonfires were burning on various premises where the plumbers were digging down to get at the service pipes. Our own pipe was frozen, and we had paid a local plumber twenty dollars for thawing it.
I was walking down Langdon Street to the laboratory one morning and passed a group of plumbers who were pushing into the frozen pipe a rubber tube attached to the spout of a portable boiler in an effort to thaw the pipe with steam. They were having trouble because they couldn’t make the tube turn a corner.
I continued on my way to the laboratory, thinking the situation over, and it came into my mind that a heavy current of electricity passed through a metal conductor raises the temperature of the metal, and that moreover an electric current would follow the conductor around any number of turns. Could not this be the solution of the whole trouble — by merely joining the faucet in the house to one wire of an electric generator and carrying the other wire to a faucet in a neighboring house?
On reaching the laboratory I went at once to the office of Professor Jackson, the head of the Department of Electrical Engineering, and suggested this plan to him. He objected to it on the ground that the current would be carried by the earth rather than by the pipes. But when I pointed out that the ground was frozen and that ice was a nonconductor, he agreed to join me in making the experiment.