Wood still had his yen for flying, despite the fact that in the 1912 naval flight with Tower — in an old box-kite Curtiss machine made with “strips of bamboo, piano wire, and bicycle saddles to sit on” — he had gone up over three thousand feet and came down (next morning) with the mumps. He now had a legitimate pretext in a lamp he’d invented for testing the use of ultraviolet rays in blind landings. He took it to Langley Field, near Norfolk, for the test flights, and was invited to go up in the afternoon for some stunt and acrobatic flying. They told him he could choose between Major So-and- So of the Air Corps, who was a great war-stunt acrobat, and Art Smith, the barnstorming circus pilot whom he’d seen skywriting at the San Francisco Fair in 1916…
Says Wood:
I chose the major, since I was in uniform myself and felt it would be more dignified to be made a monkey of — or crash — with a fellow-officer than with a circus man! As the machine took off, a lot of grinning officers came out with field glasses prepared to watch me suffer and doubtless hoping I’d get sick, which was a usual part of the fun. At three or four thousand feet we did about everything except straight upside- down flying. Loops, multiple loops, Immelmann turns, etc., ended with a proper spinning nose dive which interested me enormously, as the plane seemed merely plunging straight down without spinning toward an earth that was rotating like a great turntable, with the rim of the horizon whirling at what seemed to be twenty-five miles per second! Our morbid spectators were disappointed, I fear, despite the beauty of the stunting, for I hadn’t the expected dizziness and nausea.
Late in the evening I made the serious flight, in a thunderstorm, with an Air Corps lieutenant, for the purpose of testing my ultraviolet landing beacon. In the course of the flight, the pilot looked back at me, made a circular gesture with his arm, and nodded. I thought he was asking if I wanted to loop, and shook my head vigorously. I’d had all the looping I wanted in the afternoon. In about two seconds I discovered that he hadn’t been asking me — he’d been telling me. Down we plunged, and then sweeping up, we practically stalled at the top of the loop. I dangled by the straps as the plane hung upside down for a second or two. When we landed, the pilot said, “Well, how did you like it?” “Fine”, I replied, “but that was a rotten loop you made”. “I thought so too”, he replied cheerfully. “It was the first time I ever tried it… at night”.
Major Wood was working with General Squier’s Signal Corps in America when the armistice came. After the armistice, in February, 1919, Wood decided he wanted to return to France and see what four years of war had done to the country. It occurred to him it would be interesting to see what scientific instruments he could collect for the War Museum of the Smithsonian, either in London and Paris or in the German trenches and dugouts of the battlefields. This served as a plausible excuse for going over, and he was given a special passport. The start of this chimerical expedition is told in a letter to his wife.
When we docked at Liverpool who should come on board with a couple of British intelligence officers, but Captain Robb, whom I had known years before at Cambridge… He said not a room was to be had in Liverpool or London, but he had a big room with two beds and would take me in for the night. Two hundred and fifty first-class passengers went ashore, where they went then I can’t imagine. Went up to London the next morning and telephoned to a dozen hotels. Tonight I dine with Boys at the Royal Society Dining Club, after the meeting of the R. S. in the afternoon. Lord Rayleigh and everyone else will be there. I’m down for a talk at the Physical Society on military signaling with invisible light. None of my scientific friends who are on the British Inventions Board ever heard my name mentioned in connection with any of the suggestions or inventions I sent over. They were surprised to find I had been in military service. A special branch has been established to develop one of my things, and I’ve been asked to go down to the Portsmouth Navy Yard tomorrow for a conference with the naval officers in charge. Yesterday I was taken to a secret bureau, the laboratories of the base-censor…
Here’s the story Wood tells me about what happened at the Base Censor Bureau.
One of its departments made tests of suspected passports and other dubious documents for erased writing, superimposed writing, invisible inks, etc. They also tested similarly shirt fronts, cuffs, handkerchiefs, linen of suspected spies — even panties and petticoats if the suspected spies were female. These articles of apparel might have been written on with invisible ink — or they might have been treated with chemicals which could be used in making invisible ink when soaked in water — to be used elsewhere for invisible writing and later developed by another chemical. The British experts showed me all the various chemical methods in use for developing secret writing. They showed other interesting activities, and I was waiting with some anticipation to see what was going on inside a small cabinet with no window which stood in the middle of the laboratory with wires running through the wall and along the ceiling. I suspected its use, and finally, when no mention of the cabinet was made at all, I asked, “What goes on in there?”
“Oh, I’m sorry”, said the captain who was showing me about, “but that’s very secret. We don’t show that to anybody”.
“Ultraviolet light, I presume”, said I in a detached manner.
“What!” said the amazed captain. “What makes you think so?”
“Because I invented the method and the black glass that cuts off the visible light, and sent the formula to your Admiralty from our Science and Research Division over a year ago”.
“Will you wait a moment”, said the captain, “while I speak to the colonel?”
I was presently ushered, with suitable apologies, into the dark room.
They had a quartz mercury arc in a box, with a window of dark-blue cobalt glass, under which they placed a German passport. When you looked at it through a yellow glass plate which cuts off the blue light reflected from the paper, you could see here and there German words, not supposed to be on any passport, which gave off a small amount of yellow light when stimulated by the violet rays. I remarked that this was the method of detecting fluorescence employed by Sir George Stokes more than half a century before. I asked why they did not use ultraviolet light to start with, which produces a strong fluorescence and is invisible.