Aristotle, tutor of Alexander, and the world’s first naturalist.

Leonardo, the all-round man—­the man who could do more things, and do them well, than any other man who every lived.

Sir Isaac Newton, the mathematician, who analyzed light and discovered the law of gravitation.

Alexander von Humboldt, explorer and naturalist, who compassed the entire scientific knowledge of the world, issued his books in deluxe limited editions at his own expense, and sold them for three thousand dollars a set.

Newton and Humboldt each wore a seven and three-fourths hat.  Leonardo and Aristotle went untaped, but Pericles had a head so high and so big that he looked like a caricature, and Aristophanes, a nice man who lived at the same time, said that the head of Pericles looked like a pumpkin that had been sat upon.  All the busts of Pericles represent him wearing a helmet—­this to avoid what the artists thought an abnormality, the average Greek having a round, smooth chucklehead like that of a Bowery bartender.

America has produced two men who stand out so far beyond the rest of mankind that they form a class by themselves:  Benjamin Franklin and Thomas A. Edison.

Franklin wore a seven and a half hat; Edison wears a seven and three-fourths.

The difference in men is the difference in brain-power.  And while size does not always token quality, yet size and surface are necessary to get power, and there is no record of a man with a six and a half head ever making a ripple on the intellectual sea.  Without the cells you get no mind, and if mind exists without the cells, it has not yet been proven.  The brain is a storage-battery made up of millions of minute cells.

The weight of an average man’s brain is forty-nine ounces.  Now, Humboldt’s brain weighed fifty-six ounces, and Newton’s and Franklin’s weighed fifty-seven.  Let us hope the autopsist will not have a chance to weigh Edison’s brain for many years, but when he does the mark will register fifty-seven ounces.

An orang-utan weighs about the same as a man, but its brain weighs only a pound, against three pounds for a man.  Give a gorilla a brain weighing fifty ounces, and he would be a Methodist Presiding Elder.  Give him a brain the same size of Edison’s, say fifty-seven ounces, and instead of spending life in hunting for snakes and heaving cocoanuts at monkeys as respectable gorillas are wont, he would be weighing the world in scales of his own invention and making, and measuring the distances of the stars.

Pericles was taught by the gentle Anaxagoras, who gave all his money to the State in order that he might be free.  The State reciprocated by cutting off his head, for republics are always ungrateful.

Aristotle was a pupil of Plato and worked his way through college, sifting ashes, washing windows and sweeping sidewalks.

Leonardo was self-taught and gathered knowledge as a bee gathers honey, although honey isn’t honey until the bee digests it.