Marking dynamos for repair $10,000.00-2 hours labor $10.00; knowing where to mark $9,990.00.

I have succeeded in getting my actual work down to thirty minutes a day. That leaves me eighteen hours for engineering.

Scientific theories need reconstruction every now and then. If they didn't need reconstruction they would be facts, not theories. The more facts we know, the less radical become the changes in our theories. Hence they are becoming more and more constant. But take the theory of gravitation; it has not been changed in four hundred years.

When it comes to scientific matters the ready talkers simply run riot. There are a lot of pseudo-scientists who with a little technical jargon to spatter through their talk are always getting in the limelight... The less they know the surer they are about it.

The most important advance in the next fifty years will be in the realm of the spiritual - dealing with the spirit of thought.

Mathematics is the most exact science, and its conclusions are capable of absolute proof. But this is so only because mathematics does not attempt to draw absolute conclusions. All mathematical truths are relative, conditional. In E. T. Bell Men of Mathematics, New York: Simona and Schuster, 1937.

The mercury light doesn't show red. It makes the blood in your skin look blue-black. But see how splendidly it brings out the green in the plants.