ty.
From this point of view his mental deformity seems not unlike that of
Cavendish's, later, except that in the case of Cavendish it manifested
itself as an abnormal sensitiveness instead of an abnormal irritability.

CHRISTIAN HUYGENS

If for nothing else, the world is indebted to the man who invented the
pendulum clock, Christian Huygens (1629-1695), of the Hague, inventor,
mathematician, mechanician, astronomer, and physicist. Huygens was
the descendant of a noble and distinguished family, his father, Sir
Constantine Huygens, being a well-known poet and diplomatist. Early in
life young Huygens began his career in the legal profession, completing
his education in the juridical school at Breda; but his taste for
mathematics soon led him to neglect his legal studies, and his aptitude
for scientific researches was so marked that Descartes predicted great
things of him even while he was a mere tyro in the field of scientific
investigation.

One of his first endeavors in science was to attempt an improvement
of the telescope. Reflecting upon the process of making lenses then in
vogue, young Huygens and his brother Constantine attempted a new method
of grinding and polishing, whereby they overcame a great deal of the
spherical and chromatic aberration. With this new telescope a much
clearer field of vision was obtained, so much so that Huygens was able
to detect, among other things, a hitherto unknown satellite of Saturn.
It was these astronomical researches that led him to apply the pendulum
to regulate the movements of clocks. The need for some more exact method
of measuring time in his observations of the stars was keenly felt by
the young astronomer, and after several experiments along different
lines, Huygens hit upon the use of a swinging weight; and in 1656 made
his invention of the pendulum clock. The year following, his clock
was presented to the states-general. Accuracy as to time is absolutely
essential in astronomy, but until the invention of Huygens's clock there
was no precise, nor even approximately precise, means of measuring short
intervals.

Huygens was one of the first to adapt the micrometer to the telescope--a
mechanical device on which all the nice determination of minute
distances depends. He also took up the controversy against Hooke as
to the superiority of telescopic over plain sights to quadrants, Hooke
contending in favor of the plain. In this controversy, the subject of
which attracted w