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

The beginning of 1856 found me teaching in the family of a planter named Bryan, residing in Prince George County, Md., some fifteen or twenty miles from Washington.

In October, 1865, occurred what was, in my eyes, the greatest event in the history of the observatory. The new transit circle arrived from Berlin in its boxes.

The demonstration that no possible combination of known substances, known forms of machinery and known forms of force, can be united in a practical machine by which men shall fly along distances through the air, seems to the writer as complete as it is possible for the demonstration to be.

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

Aerial flight is one of that class of problems with which men will never have to cope