The perils of overwork are slight compared with the dangers of inactivity.

I am proud of the fact that I never invented weapons to kill.

The injurious agent in cigarettes comes principally from the burning paper wrapper. The substance thereby formed is called "acrolein." It has a violent action on the nerve centers, producing degeneration of the cells of the brain, which is quite rapid among boys. Unlike most narcotics, this degeneration is permanent and uncontrollable. I employ no person who smokes cigarettes.

It is apparent to me that the possibilities of the aeroplane, which two or three years ago were thought to hold the solution to the [flying machine] problem, have been exhausted, and that we must turn elsewhere.

Somewhere between the ages of eleven and fifteen, the average child begins to suffer from an atrophy, the paralysis of curiosity and the suspension of the power to observe. The trouble, I should judge, to lie with the schools.

Seeming to do is not doing.

I have been at work for some time building an apparatus to see if it is possible for personalities which have left this earth to communicate with us.