"Now, the moment of truth was upon Dr. Smithies.
He was standing in the pitch-black darkroom, developing x-ray film
that would reveal whether he had succeeded in gene targetting.
Dr. Smithies suddenly realized that feeling he had while he waited
for the film to develop was just like a feeling he got when he flew
airplanes, one of his passions.

It was, he said, as though he had been flying on instruments for three
years, doing molecular manipulations that led him to his final experiment.

And when you fly on instruments, he said, there is that instant when
you come out of the clouds and, if everything is done right,
the runway is right there."