Galileo at seventy-seven, blind and feeble, was working every day, adapting the principle of the pendulum to clocks.

George Stephenson did not learn to read and write until he had reached manhood.

Some of Longfellow's, Whittier's, and Tennyson's best work was done after they were seventy.
At sixty-three Dryden began the translation of the "Aeneid." Robert Hall learned Italian when past sixty, that he might read Dante in the original.

Noah Webster studied seventeen languages after he was fifty.
Cicero said well that men are like wine: age sours the bad and improves the good.
With enthusiasm we may retain the youth of the spirit until the hair is silvered, even as the Gulf Stream softens the rigors of northern Europe.
"How ages thine heart,--towards youth?
If not, doubt thy fitness for thy work.".