he
laboriously followed. He was one who might be expected to find the
proverbial "needle in a haystack," but unfortunately the needle was not
always there. Delambre says, "Ardent, restless, burning to distinguish
himself by his discoveries he attempted everything, and having once
obtained a glimpse of one, no labour was too hard for him in following
or verifying it. All his attempts had not the same success, and in fact
that was impossible. Those which have failed seem to us only fanciful;
those which have been more fortunate appear sublime. When in search of
that which really existed, he has sometimes found it; when he devoted
himself to the pursuit of a chimera, he could not but fail, but even
then he unfolded the same qualities, and that obstinate perseverance
that must triumph over all difficulties but those which are
insurmountable." Berry, in his "Short History of Astronomy," says "as
one reads chapter after chapter without a lucid, still less a correct
idea, it is impossible to refrain from regrets that the intelligence of
Kepler should have been so wasted, and it is difficult not to suspect at
times that some of the valuable results which lie embedded in this great
mass of tedious speculation were arrived at by a mere accident. On the
other hand it must not be forgotten that such accidents have a habit of
happening only to great men, and that if Kepler loved to give reins to
his imagination he was equally impressed with the necessity of
scrupulously comparing speculative results with observed facts, and of
surrendering without demur the most beloved of his fancies if it was
unable to stand this test. If Kepler had burnt three-quarters of what he
printed, we should in all probability have formed a higher opinion of
his intellectual grasp and sobriety of judgment, but we should have lost
to a great extent the impression of extraordinary enthusiasm and
industry, and of almost unequalled intellectual honesty which we now get
from a study of his works."

Professor Forbes is more enthusiastic. In his "History of Astronomy," he
refers to Kepler as "the man whose place, as is generally agreed, would
have been the most difficult to fill among all those who have
contributed to the advance of astronomical knowledge," and again _a
propos_ of Kepler's great book, "it must be obvious that he had at that
time some inkling of the meaning of his laws--universal gravitation.
From that moment the idea of universal gravitation was