Wood is no help at all in explaining why it was now given to him. On subjects of this sort he becomes impatient. He has stuck all his medals in an old dresser drawer behind his wife’s shopping lists[12]. Some of them, including the gold ones, are about the size, to exaggerate a little, of the toasted buttercakes you get in Childs. The only thing I ever found worth quoting from his notes concerning the Rumford medals was this[13]:
“You get, in each instance, a silver replica of the gold one, presumably in case you wish to cash in on your winnings in your impoverished old age. The Royal Society gold one weighs 15 1/2 ounces”.
Sir William Bragg’s speech in presenting the medal to Wood is the best summary of his achievement, and I quote, from it:
Professor Robert Williams Wood is awarded the Rumford medal. The study of physical optics owes much to Professor Wood, who has been one of the leading experimenters in this field for the past forty years. There is hardly a branch of the subject which he has not enriched by the touch of his genius.
Before the advent of Bohr’s quantum theory, when our knowledge of the structure of atoms and molecules was very meagre, he had discovered the line and continuous absorption of sodium vapor, the phenomenon of resonance radiation of gases and vapors, and the quenching of this radiation by foreign gases. These discoveries opened up rich fields of research and were of the greatest value to later workers in laying the foundations of the theory of atomic and molecular spectra.
The elucidation of the phenomenon of resonance radiation demanded the utmost experimental skill and resource. Nothing less powerful than an improvised 40 ft. focus spectrograph sufficed for his work on the remarkable resonance spectra of molecules! Even now one cannot but admire the beautiful and ingenious experiments on the independent excitation of the yellow sodium lines.
In addition to his researches on the resonance radiation of metallic and other vapours, Wood investigated their magnetic rotation and dispersion. His work on the magneto-optics of sodium vapor both in the atomic and the molecular state is now classical.
More recent but belonging to the same domain of experiment are the very interesting discoveries of Wood and Ellett on the magneto- optics of resonance radiation.
Wood’s mastery of technique is universally acknowledged. He has introduced many ingenious and striking devices to experimental method. These are too numerous to catalogue here, but I would mention specially his method of the production of atomic hydrogen and his observations of the spontaneous incandescence of substances in atomic hydrogen which led to the invention of the atomic hydrogen welding torch by Langmuir; his very efficient and now widely used method of observing Raman Spectra; his echelette grating which has proved to be the grating par excellence for the investigation of the near and far infra-red; and his pioneer use of light filters in ultra-violet and infra-red photography.
If you ask Wood himself why he got the medal, he is quite likely to tell you it was because he introduced smoking in the hitherto forbidden precincts of the Royal Society’s sacred halls! One day, long ago, tea and cakes were being served in the majestic anteroom, when Wood became absorbed in talk with Sir William Crookes and lit his pipe. A flunkey in knee breeches and braided coat appeared as if by magic and whispered, with a mixture of awe and horror:
“Very sorry, sir, but smoking is not allowed”.
Wood says he was so engrossed with Crookes that he went on smoking. Crookes stared, hastily produced a cigarette, and lighted it. In another minute, others lighted up — and the Royal Society has smoked there ever since.
If this episode were unique in Wood’s biography, it might have slight significance, but many similar smoking anecdotes are told of him, and where there’s smoke there’s always fire. One of the strongest leit motifs through this man’s whole life has been his curious, not always conscious affinity with flame. It illumines his Promethean-scientific side and is always spilling over in his pranks, both Huck Finnish and Mephistophelian. In the light of the fact that he led the revolt against Madame Curie’s objection to smoking at the Solway Conference in Brussels, had a somewhat similar adventure at the Royal Auto Club in London, etc., etc., one has the right to suspect that when he lights his pipe where he shouldn’t, the bad little boy who loves to play with fire and shock his Aunt Sally is still hiding behind the absent-minded great man and grinning.
When asked to lecture before the Philadelphia Forum, he chose “Flame” as his subject, and turned the dignified stage of the Academy into a cross between a Blitzkrieg and Vesuvius. There were sheets of blaze, acetylene torches, showering white-hot globules of molten steel — huge tubes of blue fire that whistled and shrieked before they exploded. Leopold Stokowski sat in a stage box. He had often conducted on the same stage — but this beat the burning of Moscow in the 1812 Overture… .
When the curtain went down, Wood wiped his brow, pulled out his pipe, and was striking a match, when the fireman backstage called, “Hey, you can’t do that!”
When this Promethean prankster, whom I then scarcely knew, took me for the first time to his big laboratory at Johns Hopkins, he turned his back for a couple of minutes, near a basin, then blandly offered me a handful of fire. It burned like an alcohol flame, but it was not much hotter than a cucumber[14]. I’ve a notion that if I hadn’t accepted it, I mightn’t be writing his biography.
I began trying just now to explain the serious connection between Dr. Robert Williams Wood, the Royal Society, and the gold Rumford medal. If I’ve slid into writing about Wood in Flames, it’s doubtless bad structure — but it’s all part of the same picture.
In the summer of 1939 Wood had turned seventy, and you might imagine that he’d sit down and rest for a couple of minutes, or even lie down and take a nap. Instead, the Woods were off for the West Coast again for experiments with the new type of diffraction gratings at the Lowell Observatory at Flagstaff and at the Mount Wilson Observatory at Pasadena.
Arriving in Pasadena, Gertrude went to Hollywood, where her sister was living, and Wood went to the Observatory for experimental trials of some new gratings he’d made. One placed over a three-inch Schmidt camera of five inches focus gave a fully exposed spectrum of Arcturus in five seconds. With an exposure of ten minutes he secured a sharp photograph of the spectrum of the Ring Nebula in Lyra, which was “going some” for a camera of only five inches focus. These experiments set a record for short exposure stellar spectra with a slitless spectrograph. The photographic plate was only half an inch square, but the definition of the spectrum lines was so perfect that on an enlargement of nearly thirty diameters, the lines were less than one-third of a millimeter in width.
This was preliminary to the real spectroscopic feat he’d embarked on, which was to make a diffraction grating large enough to cover the great eighteen-inch Schmidt camera, with a focus of thirty-six inches, the instrument with which Dr. F. Zwicky was discovering super novae at a rate that caused astronomers to gasp.
In the summer of 1941, Wood was throwing boomerangs at his biographer in East Hampton, and casually starting again for California, with gratings for the eighteen-inch camera.
12
Among the notable medals for outstanding scientific achievement of which Dr. Wood is the recipient are the following: 1899: medal awarded by the Royal Society of Arts for his diffraction process in color photography; 1907: the Franklin Institute John Scott medal, awarded by the City of Philadelphia for further progress in diffraction color photos; 1909: gold and silver Rumford medals awarded by the American Academy of Arts and Sciences for research on the optical properties of metallic vapors; 1910: the J. Traill Taylor medal, awarded for photography by invisible rays; 1918: gold medal, awarded by the Società Italians della Scienze, for general outstanding scientific achievement; 1933: the Frederick Ives medal, awarded by the Optical Society of America for distinguished work in physical optics; 1938: the gold and silver Rumford medals, awarded by the Royal Society, London, for his daring and genius in experimentation; 1940: the Draper gold medal, awarded by the National Academy of Science, Washington, for contributions to astrophysics and spectroscopy.
13
I managed to dig up, however, an article entitled “Americans and the Royal Society from 1783 to 1937,” written by Heathcote Heindel and published in Science, March 25, 1938, which threw more light on the general subject. Only six American physicists have ever been elected to foreign membership in the Society: 1889: Henry A. Rowland of Johns Hopkins; 1895: Samuel P. Langley of the Smithsonian Institution; 1897: J. Willard Gibbs of Yale; 1902: Albert Abraham Michelson of Chicago; 1919: Robert Williams Wood of Johns Hopkins; 1935: Irving Langmuir of the General Electric Co.
14
Cotton waste wet with a mixture of two parts of carbon tetrachloride and one part of carbon bisulphide.