Construction of an aerial vehicle which can carry even a single man . . . requires the discovery of some new metal or force. Even with such a discovery, we could not expect one to do more than carry its owner.

The reports of the eclipse parties not only described the scientific observations in great detail, but also the travels and experiences, and were sometimes marked by a piquancy not common in official documents.

I had not yet gotten into the world of light. But I felt as one who, standing outside, could knock against the wall and hear an answering knock from within.

James Edward Oliver might have been one of the great mathematicians of his time had he not been absolutely wanting in the power of continuous work.

We are probably nearing the limit of all we can know about astronomy.

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.

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