DISNEY: And so, we spent the rest of the night, then, trying to measure exactly where the pulses were coming from. It really was very close to Baade's Star, but it might have been one of two stars in the middle of the Nebula. And so we sent off a telegram, then, to the International Astronomical Union, which is a place where you tell a very exciting discovery which you want confirmed immediately. We sent it off to them, and they sent it to all observatories around the world.

Well, what was really worrying us is we couldn't eliminate the possibility that, which—you know, we didn't know really—which of the two stars in the middle of the Nebula was the pulsar. We knew it was one of them, we couldn't be absolutely sure. And to do that, we really needed a bigger telescope. And we realized now that, having sent this telegram off, there'd be a lot of people working on the pulsar. And indeed, it turned out that the people at Kitt Peak National Observatory itself, on the very same mountain, were going to work on it the following night, too.

There was a lot of interesting stuff to be done. And we weren't sure really, how we were going to do any of it, because we didn't have the right telescope. Well, we came to the conclusion that if we were going to find out which star it was, we were going to need a smaller diaphragm—that's a very small thing which can discriminate between one bit of the sky and the other—and we had to do it before the next evening.

So I remember, we spent the whole day with some kitchen tinfoil from the kitchen trying to make a tiny little hole in this thing, about a tenth of a millimeter square. We finally succeeded in doing this, to everyone's amazement. We had—I can remember all four of us working on it, John, Don, Bob McCallister, and myself— and we had a microscope, which we'd found somewhere in the building. And we were looking through this microscope—this tiny piece of kitchen tinfoil—working with pairs of tweezers and razor blades and so on. And when the guy who was making the actual cuts—I think John was actually doing the brain surgery— everybody held their breath tight after he drew a line, or cut a line, in the tinfoil. But anyway, around about 5 o'clock we finally had the diaphragm, which we gingerly placed into the telescope.

And by this time, we'd had several phone calls from people, either congratulating us, or asking questions about the pulsar. We knew they were all going to work on it, so we felt this tremendous rush to get this thing and prove which star it was. It was kind of a race, you see.

Well, as soon as it was dark, we set everything up. And Don Taylor had a damn clever idea. In order to find the pulsar exactly, he was going to find it by ear, by listening to his photometer. That's to say, he let the incoming light waves cause a microphone to make a little brrrrrrgh noise, and when we were on the pulsar, it would make a louder brrrrrrgh. And so Don would be sitting there in the dark with his ear against the microphone, while John and I were watching the screen. And Don would drive the telescope about fairly blindly around in the right position. When he got to the right position with this very tiny diaphragm, the brrrrrrgh would suddenly rise in tone. And we'd watch the screen to see if it was pulsing source as well. And just about half past eight, nine o'clock, we finally picked up one of the stars this way. And it had a pulse. We could see the pulse on the screen, and Don could hear it on the microphone. And we were positive now it was the South Preceding star. That's to say, Baade's original guess at the right star.