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

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

My father followed, during most of his life, the precarious occupation of a country school teacher.

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.

As the existence of a corps of professors of mathematics is peculiar to our navy, as well as an apparent, perhaps a real, anomaly, some account of it may be of interest.

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

A few years later the Naval Academy was founded at Annapolis, and a similar course was pursued to provide it with a corps of instructors.