Robert Wood was the great man in experimental optics. He was full of playfulness. I imagine very few people nowadays have seen his book, called 'How to Tell the Birds from the Flowers'. His fanciful drawings in which the colored object could be a bird or it could be a flower. Robert Wood liked to have practical jokes. He would invite somebody to swallow some liquid air- nobody volunteered but Wood himself would take some liquid air into his mouth. And the fumes of the vaporizing liquid air coming out of his mouth made a spectacular sight. And another spectacular sight was a smoke ring generator. You tapped the back of it after it was filled with smoke, and out would come a great ring of smoke which would go across the room. But he lectured us on how powerful the theorem is that the vorticity cannot break off, it has to continue all the way around the circle. And after having emphasized that point, he ridiculed the mathematics, because he had never been able to pass the mathematics to get a Doctor's degree himself. He taught without benefit of a PhD. In order to ridicule the mathematics, he produced for us a smoke ring that was only half a circle. And what happened to the other half? The other half was there in invisible air, just not any smoke to make it show up. But in addition to Wood, keeping on the tradition of optics at Johns Hopkins, there was Pfund, P F U N D, who made working with things optical an absolute joy. All kinds of gadgetry. Then there was a new arrival, Dieke, from the Netherlands, who combined knowledge of spectra, especially Spectra of Molecules, with the modern Quantum Mechanics, to describe the- and he was- had been brought in to modernize the curriculum in the physics department with more emphasis on modern quantum points of view. And then there was Joyce Bearden who worked at the other end of the spectrum, X-rays. Robert Wood was a member of the Royal Society and made annually a visit to England. And he was given the task of bringing back somebody who could teach something about the new field of nuclear physics. He brought back a quite young man from Rutherford's laboratory, Norman Feather. And the young fellows in the laboratory, the younger teachers, embarked with enthusiasm on a new scheme of providing a month of instruction, working in their own laboratories, with this or that student. So I worked for a month with Feather, for example, who went to the basement, sat there for half an hour in the dark, until my eyes adapted enough so I could see flashes when particles from radium hit a screen of zinc sulfide. These flashes of light you count, and count again some hours later, and see how the radioactivity falls off with time, from radon gas. Nowadays, people make a great thing about the radon in people's basements, and trying to protect themselves from radioactivity, but here I was trying to measure it. And then, with Bearden on X-rays. Then I found myself trying to explain the penetration of X-rays. And we wrote a couple of papers together. With Dieke, I'm afraid my experience did not lead to any paper. I learned a bit about spectroscopy in the infra-red, but that was it.