In Dante's time nearly every literary man in Italy was a hard-working merchant, physician, statesman, judge, or soldier.
While Michael Faraday was employed binding books, he devoted all his leisure to experiments.

At one time he wrote to a friend, "Time is all I require.

Oh, that I could purchase at a cheap rate some of our modern gentlemen's spare hours--nay, days." Oh, the power of ceaseless industry to perform miracles! Alexander von Humboldt's days were so occupied with his business that he had to pursue his scientific labors in the night or early morning, while others were asleep.
One hour a day withdrawn from frivolous pursuits and profitably employed would enable any man of ordinary capacity to master a complete science.
One hour a day would in ten years make an ignorant man a well-informed man.

It would earn enough to pay for two daily and two weekly papers, two leading magazines, and at least a dozen good books.

In an hour a day a boy or girl could read twenty pages thoughtfully--over seven thousand pages, or eighteen large volumes in a year.