I note that Newcomb's first published work was pedagogical: a response to a letter published in "National Intelligencer" that "refuted" the Copernican universe (1855). Today some of the questions that vexed the "inquiring layman" in Newcomb's time have been resolved by direct observation.
Newcomb reports (in his 1903 memoir) the following exchange with a visitor to his office:
"Professor, I have called to tell you that I don't believe in Sir Isaac Newton's theory of gravitation! ... What I mean is I don't believe in the Newtonian theory that gravitation goes up to the moon. It doesn't extend above the air."
"Have you ever been up there to see?"
There was an embarrassing pause, during which the visitor began to look a little sheepish.
"N-no-o," he replied at length.
"Well, I haven't been there either, and until one of us can get up there and try the experiment, I don't believe we shall ever agree on the subject..."
The idea that the facts of nature are to be brought out by observation is one which is singularly foreign not only to people of this class ["paradoxers"], but even to sensible men. When the great comet of 1882 was discovered in the neighborhood of the sun, the fact was telegraphed that it might been seen with the naked eye, even in the sun's neighborhood. A news reporter came to my office with this statement, and wanted to know if it was really true...
"I don't know," I replied; "suppose you go out and look for yourself; that is the best way to settle the question."