If so, it must have marked the passage of every sunny hour that has elapsed since Isaac Newton was a boy.

It marked all the famous moments of his life; it marked the hour of his death; and still the sunshine creeps slowly over it, as regularly as when Isaac first set it up.
Yet we must not say that the sundial has lasted longer than its maker; for Isaac Newton will exist long after the dial--yes, and long after the sun itself--shall have crumbled to decay.
Isaac possessed a wonderful faculty of acquiring knowledge by the simplest means.

For instance, what method do you suppose he took to find out the strength of the wind?
You will never guess how the boy could compel that unseen, inconstant, and ungovernable wonder, the wind, to tell him the measure of its strength.

Yet nothing can be more simple.

He jumped against the wind; and by the length of his jump he could calculate the force of a gentle breeze, a brisk gale, or a tempest.