Doctor Wood. Modern Wizard of the Laboratory: The Story of an American Small Boy Who Became the Most Daring and Original Experimental Physicist of Our Day-but Never Grew Up

Chapter Ten. The Cat and the Telescope

Wood’s invention of the so-called mercury telescope — a revolving dish of quicksilver at the bottom of a pit — was one of the most sensational, useless, and significant things he ever did. It was constructed on the principle that mercury in a shallow metal dish, when rotated, assumes the form of a paraboloidal reflecting mirror. The dish of mercury was placed at the bottom of a well beneath an old cowshed with a hole ripped in its roof, and rotated slowly by a motor while the observer at the top of the well looked down through an eyepiece lens at the enlarged, reflected images of celestial bodies as they crossed the zenith.

Wood had the machine built by Warner and Swasey of Cleveland, the celebrated makers of large astronomical telescopes. Every conceivable refinement had to be made to secure a smooth rotation of the dish of mercury, since any jar to the dish would cause ripples on the surface of the mercury and distort the images formed in the mirror. Wood had the brilliant idea of accomplishing this by surrounding the mercury dish with an independently mounted rotating collar, driven by an electric motor and attached to the mercury dish only by thin bands of rubber. These rotated the dish without transmitting the vibrations of the motor. The focal length of the instrument could be varied from four to fourteen feet by altering the speed of the motor. Standing at the edge of the well and looking down into it, one saw the images of the overhead stars, enhanced to the brilliance of distant arc lights, suspended in space at the mouth of the well — an especially marvelous sight when the great star cluster in the constellation of Hercules crossed the zenith.

On August 27, 1908, the New York Times gave the entire streamered front page of its Section II to a profusely illustrated piece entitled:

A NEW IDEA FOR READING THE STARS

Wood of Johns Hopkins at East Hampton Working on a Telescope that isn’t a Telescope with a Lens that isn’t a Lens.

On Sunday April 11, 1909, the Baltimore Sun eructed an even more sensational front-page spread, with black-and-white drawings of Wood looking like Tarzan, a huge hunk of cratered moon resembling Swiss green cheese, the ripped-up cowshed looking like a cowshed, and the diagramed gadgets in a cross section of the well beneath it resembling nothing then on earth, but presaging the cartoons that were later to make Rube Goldberg famous. The headlines were equally diverting.

New Telescope May Solve the Riddle of the Universe!

IS MARS INHABITED?

MERCURY REFLECTOR INVENTED BY BALTIMORE GENIUS TO BRING THE MOON WITHIN A FEW MILES OF EARTH.

The Associated Press and popular science syndicates went to town on it, while the cowshed became a shrine for pilgrimages of scientists and curiosity-seekers. It got on the cables. The French gazettes wrote about the “Puits et Plancher Poulie”; the Berlin journals announced the epoch-making invention of “Ein originelles Spiegelteleskop." A couple of Teutonic astronomers made the pilgrimage, peered down into the well, exclaimed, “Gott in Himmell Wunderschön”

The idea which excited everybody was that if a twenty-inch dish of quicksilver at the bottom of an old well under a cowshed could work such wonders, then a twenty-foot dish down a mighty mine shaft, as it were, would bring the moon to Baltimore and the Bronx. Even the Boston Transcript began to get excited over signaling the Martians — though Wood himself, needless to say, had never made nor countenanced any such fantastic blurb-and-boloney bunk.

Arthur Gordon Webster, then head of the Department of Physics at Clark University, who was one of the first to visit East Hampton, had been humorously scornful of the mercury telescope, and had written in the Wood guest book the jingle which appears at the head of this chapter. The astronomer W. H. Pickering had come visiting later, and after Wood had resolved the quadruple star Epsilon Lyrae for him in the mercury telescope, he had written in the same guest book the following happy pun:

His brother, the even more famous Edward Pickering, director of the Harvard Observatory, said, at the top of all the first excitement, “I think we’d better wait..”.

And Wood himself — who had found an old penciled record on the cowshed door, “Heifer calf, May 1860”, and added in his own scrawl, “Mercury telescope, June 1908” — was in complete accord with Pickering.

Not so, however, the great Empire State of Texas. The Texans were all for signaling Mars instanter. The idea of waiting didn’t appeal to them at all — nor to that late great religious- fundamentalist archaeologist, the Reverend Professor William S. Cole of Atlanta, Georgia, and the Bible Belt. He felt that God had inspired Professor Wood and that we might obtain even a glimpse of the Pearly Gates through the roof of the humble cowshed. Professor Cole had no financial backing and couldn’t get going on his idea, but wealthy Texas began bombarding Wood with telegrams. The first one came from Fort Worth, was signed by the Star Telegram, and read: “What would it cost to establish plant in West Texas to observe Mars with your mercury reflection would you be willing to conduct experiment large uninhabited areas clarified atmosphere and altitude make conditions perfect”.

On its heels the same day came another urgent wire: “Kindly let us know if you are willing to establish experimental plant huge mercury mirrors if all expenses guaranteed Stamford Texas will stand for ten thousand dollars perhaps more please answer”.

When Dr. Wood replied declining the offer and explained to the newspapers and Associated Press that he hadn’t the remotest idea of going to Texas or trying to signal Mars, the Texans frantically raised the ante to $50,000 and wired: “We will do all we can to help you and assure you we are in earnest”.

Even this failed to melt the professor’s heart. In fact he became a bit impatient and ironic. When prodded by the New York Herald about schemes for signaling Mars, including one which involved covering several square miles of desert with mirrors, he wrote in reply:

As to the project of attracting the attention of the Martians to the fact that there are rational beings on the earth, it seems to me that if there are any who insist upon making us conspicuous in this way it would be better to devise some simpler way than the construction of a mirror several miles in diameter. A large black spot on the white alkali plains could be constructed at much less expense, and would be as easily perceived by the Martians, if they exist and have telescopes as powerful as ours. It would be as easy to “wink” signals with the black spot as with a mirror of equal size, probably easier.

The spot could be made in small sections of black cloth arranged to roll up on long cylinders, exposing the white ground underneath, the cylinders being operated simultaneously by electric motors. I am unable to say how much four square miles of cloth would cost. You will have to consult the dry goods houses or the people who write arithmetic.

We should probably get an answer, for the Martians are supposedly older and wiser than we are.

I have never, and am not now, giving any attention at all to the problem of signaling to Mars.

I don’t think we need go any further to justify my adjective “sensational”. Nor need we blame Professor Wood for the sensationalism. He has perpetrated some gigantic and Gargantuan hoaxes — as hoaxes — but is of a rigid, almost ultraconservative integrity in the field of serious science. He had never sanctioned any of the fantastic and gratuitous predictions. Indeed, he had never claimed anything for the mercury telescope. He had merely invented it, and there it was…

As for my second adjective, “useless”… well, the mercury telescope isn’t there, or anywhere, any more. When the moon rises over the cowshed, no mirror flashes, no Katie waits, and no quicksilver gleams. It has gone the way of the heifer calf. It just didn’t work out pragmatically. One thing I wondered about, and which may have had something to do with its demise, was how the hell you could point a hole in the ground at the particular planet, star, or galaxy you wanted to study at the time? Wood says my wonder is justified, and that later he mounted over the pit a twenty-inch plane mirror of silvered glass and was able to view objects which were widely removed from the zenith. I doubt if it could have helped much.

Now to justify our third adjective, as to its being one of the most “significant” things Wood ever did. The method of driving the mirror with an independent circular rotor he subsequently applied to all of the dividing engines used for ruling diffraction gratings, and at once got rid of certain errors in the proper spacing of the lines. It has since become a standard engineering practice. So, despite its immediate uselessness, the whole thing was of an instructive significance, as an example of how your pure scientist sets himself a problem — which may or may not lead to practical results — and solves the problem by breaking it into its component parts and dealing separately with each. Wood’s own technical description (written at the time and preserved in his scientific papers) of the problem, its motivations and the technique employed in solving it, is a clear, modest, and illuminating exposition of how the wheels go round — in the making of a mercury telescope and also in the scientific brain.

Before it went into limbo, the mercury dish mirrored one profound reflection, not of starlight but of rural American philosophy. It was during the Bryan-Taft campaign, and an old East Hampton farmer, after staring at the myriad stars reflected in the mercury telescope, sighed and said,

“Well, I don’t know as it makes so much difference after all whether Taft or Bryan’s elected..”.

The old farmer’s reflection was profound, but was it original? Or have people been saying it since the time of Pythagoras?

Now while the mercury telescope was following the heifer calf into oblivion, Wood was already engaged in the construction — in this same unique barn-cowshed-laboratory at East Hampton — of a gigantic spectroscope, or rather spectroscopic camera, which was destined to become an entirely different kettle of cats. It was, and for years continued to be, the largest and best instrument of its sort in the world, and in addition to making the Woods’ house cat as immortal as the parrot of Archimedes, it marked an epochal advance in spectral knowledge and analysis. One of the many things it did was to resolve for the first time the complicated spectrum of iodine, which has some forty thousand lines. But whenever this is mentioned by scientists and physicists, whether here or in Tokyo or Singapore, somebody always interrupts to tell the story of the cat, so I think I’d better follow custom and dispose of the Wood pussy. There are many versions of the story. It was twisted by Time a couple of years ago, and became a sort of feline Rin-Tin-Tin animal serial in the hands of the newspaper feature writers, who turned the cat into a permanent magician’s assistant and had it regularly doing its stunt whenever Wood called, “Pussy, pussy, come and clean the cobwebs”. It had, indeed, so many variants that I’m not sure Wood himself is any longer able to give a trustworthy account, and the cat cannot be interviewed because she’s dead. Yet what apparently actually happened is simple and easily told. The spectroscope had a long wooden tube, forty-two feet in length and six inches or so in diameter, projecting out through the side of the barn, to an iron post in the cowyard, fitted at one end with a diffraction grating and at the other with a slit and a mirror. During the first winter and spring after its construction, the spiders got in and wove their webs. When Wood came down in June he spied the arachnean invasion. He grabbed the family cat and stuck it — not without a struggle — into one end of the tube, which he then closed up. Pussy, having no alternative, squirmed her way through the tunnel towards the daylight and bounded out at the other end trailing a bridal veil of spiderwebs over the fence and across the lawn. It hadn’t occurred to the Professor that it would be long remembered, though he casually mentioned the episode in a technical paper in the Philosophical Magazine. It was just a quick, efficient, costless way of obtaining a desired result with whatever came nearest to hand.

This spectroscopic camera was a marvel of scientific — and practical — ingenuity. Friends, fellow-scientists, curiosity-seekers, and journalists again flocked to the now world-famous barn. There are many clippings, some highly technical, which describe what was going on there in 1912. The picture which comes clearest to me is the description which appeared in the Brooklyn Daily Eagle of Sunday, September 1, 1912, in which the writer said:

One passing along the road would never suspect that the place was other than a quaint building housing farm animals until the professor swings open the huge doors and shows you the interior.

The new spectroscope, which the professor built entirely himself, is essentially so simple a mechanism that one would hardly expect any startling results could be obtained from it. It consists of a long wooden tunnel, forty-two feet in length and seven inches square, terminating at one end in an achromatic lens, six inches in diameter, having a forty-two-foot focus, just the length of the tunnel. Beyond the lens, at the same end, is the diffracting grating which decomposes the light into the prismatic colors. This grating is a piece of polished metal ruled with diamond scratches, 15,000 to the inch, making a total of 75,000 vertical lines on the whole surface, which is five inches square.

The grating rotates on a vertical axis, turned by a rod and gearing wheel, so that the professor may use any part of the spectrum he wishes at a time. The instrument is so powerful that only a small part can be used at a time. The lines on the polished plate act just the same as a prism in diffracting or decomposing the light into the prismatic colors, but make the instrument much more powerful than an ordinary prism.

At the other end of the tunnel, which terminates in a dark room, is a small slit and back of that a mirror on which the sunlight is reflected from the outside by means of another mirror and a lens. This reflecting mirror and lens work as a heliostat revolving by clockwork, with the motion of the sun, so that the reflected light is always on the mirror at the dark end of the tunnel, which in turn always reflects this light through the slit to the achromatic lens and the diffraction grating. When the light is decomposed by the grating and sent back through the tunnel it is tilted slightly upward so that a photographic plate inserted just above the slit will take a photograph of the section of the spectrum on which the professor is working.

The wonderful power this instrument has in diffracting color and decomposing the spectrum is shown in many ways, each of which manifests its superiority over previous spectroscopes and the results obtained by them. In the first place, the professor said, in a small laboratory spectroscope what is known as the yellow sodium line appears as a single line, while in this new spectroscope this same line… appears as two distinct lines, separated by a distance of 5 inches!

Furthermore, the entire spectrum as seen by this instrument would be 50 feet long, while the finished spectrum magnified three times in order to study the various spectrum lines would be 150 feet in length. This is the length to which the spectrum studied by Professor Wood is extended, although he is not interested in the entire spectrum but only one part connected with his study and research work.

Professor Wood is now making a study of the absorption spectrum of iodine in connection with some other work along the same lines which he did last summer.

Despite the unwilling co-operation of the family cat, the wooden tunnel of the original East Hampton spectroscope became unsatisfactory. Wood had built a shingled roofing along its full length. But rains and snow finally wet and warped it. So he decided to build a new tunnel underground, using sewer pipe. East Hampton had a stone mason and pipe- layer by the name of Barnes, with whom Wood had been on terms of complete understanding since the episode of the baptismal font. There are various versions of that story too. Here’s what Wood tells me actually happened.

Barnes was doing some work for us while we were renovating the place, shortly after its purchase. He was building the cesspool. One day when our own car balked, I rode downtown with him on the seat of his cart, with barrels and sieves rattling behind. As we were passing through the village, the new rector of the chapel at Amagansett came hurriedly toward us, holding up his hand as a stop signal.

“Good morning, Mr. Barnes. I trust, Mr. Barnes”, he unctuously intoned, “that you will bear in mind that you promised to come to Amagansett at your earliest opportunity and lay our new baptismal font”.

“Yes, Doc”, replied Barnes, “I’ll build your baptismal font soon’s I can, but I got to finish the Prof’s cesspool fust”.

Barnes’s comeback had so enchanted Wood that he sent for him later to build the new spectroscope tunnel. The problem, of course, was to keep the tunnel, built of terra-cotta sewer pipes with walls of irregular thickness, absolutely straight and smooth inside. This was a problem that had never confronted Barnes before.

Wood put a heliostat (a mirror operated by clockwork) in the pit at the end of the forty-foot trench, which reflected a horizontal beam of sunlight three inches above the trench bottom. He told Barnes to lay the pipes along the beam of light, each pipe being adjusted so that the circular spot of light was exactly at the center of a sheet of white paper held against its end. When the job was finished and viewed from the outside, it seemed as full of irregular little humps and twists as a convulsed snake which had tried and failed to straighten out. Barnes said disgustedly, “That’s the worst job I ever did”. Wood said, “Look through it”. Barnes looked and said, “Gosh!”

It was straight as the bore of a rifle — on the inside.

JOHNS HOPKINS PROFESSOR: Wood in 1901, when he became professor of experimental physics at Johns Hopkins University.

THE MERCURY TELESCOPE: Here we see the spinning bowl of mercury reflecting the face of Wood as he gazes at it. Since the mirror is concave, reversing reflected images, Wood’s reflection appears right side up. This photograph was taken in the barn laboratory at East Hampton, where the preliminary work was done. Later the mercury telescope was moved to a pit under an adjacent cowshed.