Clyde Tombaugh: I was assigned to taking photographs at night with the telescope. It was a wide-angle photographic telescope with a one-hour exposure. Then I developed the plates, and so on, and a few days later, I would put them on a special machine called the Blink Comparator, where you compared two plates rapidly in alternating views to see if any change occurred on the starfield from one plate to the other made a few nights later. That was the technique because these plates would have several hundred thousand star images a piece — and if you don’t think that’s an awesome thing to look at and realize you had to see all those images — which one moved, you see.  So the challenge there was far more difficult than most people ever realized.

But I had some soul-searching questions of myself. Do I want to go through this very tedious job or not? But I didn’t want to go back to the farm to pitch hay, and I knew that they’d hired me to do this job, so either I do this job or go back to the farm. So I went through some pretty tedious hardship cases to accomplish this, but I was dedicated, and I liked the work, really, and I was very, very careful. All the suspects were checked with a third plate, did the job very thoroughly, and it paid off. That’s where others failed because they were not careful enough. Their strategy was not good, and I had thought this thing out very carefully in my own mind of how to do this, you see, and it worked.