Flight by machines heavier than air is unpractical and insignificant, if not utterly impossible.

One hardly knows where, in the history of science, to look for an important movement that had its effective start in so pure and simple an accident as that which led to the building of the great Washington telescope, and went on to the discovery of the satellites of Mars.

I was taught the alphabet by my aunts before I was four years old, and I was reading the Bible in class and beginning geography when I was six.

In 1860 a total eclipse of the sun was visible in British America.

What we now call school training, the pursuit of fixed studies at stated hours under the constant guidance of a teacher, I could scarcely be said to have enjoyed.

My first undertaking in the way of scientific experiment was in the field of economics and psychology.

So far as the economic condition of society and the general mode of living and thinking were concerned, I might claim to have lived in the time of the American Revolution.