that the greatest of Dutch statesmen might have become
famous as a mathematician had the cares of administration
permitted him to pursue the abstract studies that
he loved. Of the scientific achievements of Christian
Huyghens (1629-95), the brilliant son of a brilliant
father, it is difficult to speak in adequate terms.
There is scarcely any name in the annals of science
that stands higher than his. His abilities, as
a pure mathematician, place him in the front rank among
mathematicians of all time; and yet the services that
he rendered to mathematical science were surpassed
by his extraordinary capacity for the combination
of theory with practice. His powers of invention,
of broad generalisation, of originality of thought
were almost unbounded. Among the mathematical
problems with which he dealt successfully were the
theory of numbers, the squaring of the circle and the
calculation of chances. To him we owe the conception
of the law of the conservation of energy, of the motion
of the centre of gravity, and of the undulatory theory
of light. He expounded the laws of the motion
of the pendulum, increased the power of the telescope,
invented the micrometer, discovered the rings and
satellites of Saturn, constructed the first pendulum
clock, and a machine, called the gunpowder machine,
in principle the precursor of the steam engine.
For sheer brain power and inventive genius Christian
Huyghens was a giant. He spent the later years
of his life in Paris, where he was one of the founders
and original members of the Academie des Sciences.
Two other names of scientists, who gained a European
reputation for original research and permanent additions
to knowledge, must be mentioned; those of Antoni van
Leeuwenhoek (1632-1723), and of Jan Swammerdam (1637-80).
Leeuwenhoek was a life-long observer of minute life.
The microscope (the invention of which was due to
a Dutchman, Cornelius Drebbel) was the favourite instrument
of his patient investigations, and he was able greatly
to improve its mechanism and powers. Among the
results of his labours was the discovery of the infusoria,
and the collection of a valuable mass of information
concerning the circulation of the blood and the structure
of the eye and brain. Swammerdam was a naturalist
who devoted himself to the study of the habits and
the metamorphoses of insects, and he may be regarded
as the founder of this most important branch of scientific
enquiry. His work forms the basis on which all
subsequent knowledge on this subject has been built
up.
To say that the school of Dutch painting attained its zenith in the period of Frederick Henry and the decades which preceded and followed it, is scarcely necessary. It was the age of Rembrandt. The works of that great master and of his contemporaries, most of whom were influenced and many dominated by his genius, are well known to every lover of art, and are to be seen in every collection of pictures in Europe. One has, however, to visit the Rijks