is as when one is considering Shakspeare: _King Lear_,
_Macbeth_, _Othello_,--surely a sufficient achievement,--but the
masterpiece remains.

Comparisons in different departments are but little help perhaps,
nevertheless it seems to me that in his own department, and considered
simply as a man of science, Newton towers head and shoulders over, not
only his contemporaries--that is a small matter--but over every other
scientific man who has ever lived, in a way that we can find no parallel
for in other departments. Other nations admit his scientific
pre-eminence with as much alacrity as we do.

Well, we have arrived at the year 1672 and his election to the Royal
Society. During the first year of his membership there was read at one
of the meetings a paper giving an account of a very careful
determination of the length of a degree (_i.e._ of the size of the
earth), which had been made by Picard near Paris. The length of the
degree turned out to be not sixty miles, but nearly seventy miles. How
soon Newton heard of this we do not learn--probably not for some
years,--Cambridge was not so near London then as it is now, but
ultimately it was brought to his notice. Armed with this new datum, his
old speculation concerning gravity occurred to him. He had worked out
the mechanics of the solar system on a certain hypothesis, but it had
remained a hypothesis somewhat out of harmony with apparent fact. What
if it should turn out to be true after all!

He took out his old papers and began again the calculation. If gravity
were the force keeping the moon in its orbit, it would fall toward the
earth sixteen feet every minute. How far did it fall? The newly known
size of the earth would modify the figures: with intense excitement he
runs through the working, his mind leaps before his hand, and as he
perceives the answer to be coming out right, all the infinite meaning
and scope of his mighty discovery flashes upon him, and he can no longer
see the paper. He throws down the pen; and the secret of the universe
is, to one man, known.

But of course it had to be worked out. The meaning might flash upon him,
but its full detail required years of elaboration; and deeper and deeper
consequences revealed themselves to him as he proceeded.

For two years he devoted himself solely to this one object. During
those years he lived but to calculate and think, and the most ludicrous
stories are told concerning his entire absorption and inattentio