The customs officer emptied the case, putting all the glass together, prisms, lenses, and bulbs in one lot, brass gadgets in another lot, rubber tubes in another; and then weighed each lot, noting the weights on a card. He then spent five or ten minutes looking up the rate on glass, brass, and rubber articles, and the quartz mercury lamp, and since he couldn’t properly classify this, about another quarter of an hour slipped by. Finally he added up the column, then added it again to make sure that no mistake had been made, and said triumphantly, “Na — Ja, ja, Sie haben was zu bezahlen! Sie bezahlen zwei Mark fünf und vierzig Pfennig". The English equivalent would be roughly, “You bet your life you have duty to pay! You pay two marks and forty-five pfennigs”. Sixty-two cents for three-quarters of an hour of an official’s misspent time.
Back in Berlin, Wood continued his research, in collaboration with Professor James Franck, subsequently a Nobel prize winner. They had previously worked together on the reduction of intensity of the iodine vapor in fluorescence caused by admixtures of chemically inert gases, and they now made the remarkable discovery that when helium gas was mixed with the iodine vapor, the spectrum of widely separated lines emitted by the vapor when illuminated by the green light of the mercury arc, which Wood had discovered a few weeks before, was transformed into a band spectrum of many hundreds of lines. The theoretical physicists, who occupied themselves with the problems connected with the radiation of atoms and molecules, were unable to find any plausible explanation for any of these effects, and it was not until many years later that they were completely understood, as will appear later. The research with Franck was completed in a couple of weeks, and the paper sent off to the English and German journals of physics.
The Woods next gathered up the family and went to St.- Moritz for Christmas and winter sports. Here Wood got on real skis for the first time, and would have nothing to do with sleds or skates. An ice rink, made by flooding a half-acre rectangle behind the hotel, had no attraction for him. He refused to take lessons, but watched the experts, and bought a book on Skiing without Tears or something of that sort, and at the end of the week could execute in low gear what he optimistically called a Telemark. At the end of the second week, high speed, without sharp turns or sudden stops, did not trouble him, and he had a great thrill, he says, “when, after a climb of over two hours up the mountain behind the village, with spots that called for ‘herring-boning,’ I came down against the wind and sun in one long, wild rush, immunized against terror by excitement, and like Mark Twain in his ‘Lost on the Mountain,’ finally found myself in the back yard of the hotel”.
From St.-Moritz the Woods went to Paris, and Wood started an investigation with an Englishman, Hemsalech, in the laboratory of the Sorbonne, on a new radiant emission from the spark which he had discovered in Baltimore. He also carried out some more accurate measurements of the iodine emission lines than he had been able to make in Berlin.
In the early spring Wood and his wife made a trip to Sicily, and it was here, when the almond blossoms were pinkest, that he made his best and most striking infrared photographs, which were exhibited at the annual exhibition of the Royal Photographic Society a little later and published in the Illustrated London News. They stayed at the Hotel Politi in Syracuse, perched on the brink of the deep quarries of Latomia, in which the hundreds of Athenian prisoners were confined and starved to death after the defeat of Alcibiades by the Syracusians in 414 B.C.. In these quarries Wood made some striking infrared photographs.
I was intrigued greatly (says Wood) by seeing what purported to be the tomb of Archimedes. Reading in boyhood in my father’s old copy of Arnott’s physics about the screw pump for raising water, invented by Ar-kimmy-des (as I always pronounced it), I had constructed one by winding a long piece of lead pipe in a spiral around an old rolling pin from the kitchen closet. History says Archimedes set little value on his mechanical inventions, regarding them as beneath the dignity of pure science, but they were the things that appealed to the popular imagination and have kept his name alive after a lapse of over two thousand years — rather than his contributions to geometry and mathematics.
Wood also is annoyed sometimes when his electrical thaw, his fish-eye views, his color photography process, and other mechanical inventions are stressed in the newspapers as his major achievements.
From Sicily they went to London early in May, 1911, where Wood had been invited to give one of the “Friday evening discourses” at the Royal Institution, founded in 1799 by Count Rumford.
The Friday evening discourses dated back to the time of Sir Humphry Davy and Michael Faraday (whose experiments with electric currents laid the foundations for modern electrical engineering). They were of a semipopular nature, but were full-dress affairs, attended almost exclusively by prominent figures in scientific fields accompanied by their ladies. The lecture hall and its horseshoe-shaped lecture table were the same as they had been when Blaikley did his admirable painting showing Faraday behind the table on which his crude little coils and magnets are displayed, delivering a Friday evening lecture, on December 27, 1855. Wood had often seen the picture, and as a young instructor at Madison had possibly dreamed of one day standing behind this same lecture table, covered with his fluorescent tubes and bulbs, his ultraviolet lamps, electric sparks, and other scientific paraphernalia. Now his dream was coming true.
After the audience is seated (says Wood) there comes a hush in the conversation, and the lecturer and his family, if present, are ushered into the room through a door, previously closed and guarded, behind and a little to one side of the lecture table.
His Grace, the Duke of Northumberland, not being available at the time, Gertrude entered the hall on the arm of the Right Honorable Earl Cathcart, Vice-President, followed by my daughter Margaret, on the arm of diminutive Sir William Crookes, who came nearly up to her shoulder and whose long white mustache, waxed at the ends into two sharp spikes, fascinated her. I brought up the rear. There was a brief introduction and at last I was standing behind the famous lecture table, giving my talk on the recent experiments I had made with invisible light…
The morning after the lecture I was back at the rooms of the Institution, removing my apparatus and putting away in the glass cases such things as I had borrowed. Spying the largest Nicol polarizing prisms that I had ever seen, I asked Sir James Dewar, the director, if I could use them for a study of the polarization of the lines of my newly discovered resonance spectrum of iodine. It was of immense importance to discover if, when the fluorescence spectrum was excited by polarized light of a single color, such as the green line of the mercury arc, any or all of the eighteen lines of the fluorescent spectrum were also polarized. Dewar gave me a nice room to work in and everything that I required. It was going to be a tough job, needing a huge amount of polarized light, large mirrors, and lenses for concentrating it on the bulb containing the iodine vapor, and the big Nicol prisms for polarizing the light. Bulbs had disadvantages, and I adopted a long glass tube of good size with a bulb blown on one end and the other end drawn down like a cow’s horn, bent off to one side and painted black. This served as a dead black background against which the fluorescence could be viewed through the bulb without disturbing reflections from the glass wall. I employed two very powerful quartz mercury arcs, one above and the other to one side of the tube, a huge concave mirror behind each lamp, and two large condensing lenses between the lamps and the tube. The research was completed in a week; all of the lines were found to be strongly polarized and there were excellent photographs showing the dark bands, which indicated polarization, cutting across all of the lines. A twelve-page paper, illustrated with photographs, appeared in the Philosophical Magazine shortly afterwards. This was the fastest work that I had ever done, which was a piece of good luck, for on the day on which I had written finis to it, Dewar strolled in with his hands behind his back under the tails of his frock coat and told me gruffly, as was his habit sometimes, that I’d have to vacate my room, since Marconi was giving the next Friday evening discourse and would need it for setting up and trying out his experiments. “I’m finished”, I said, “and thank you very much”.