lso held "that
the square of the periodic time of any planet is proportional to the
cube of its mean distance from the sun," and "that the area swept by
the radius vector from the planet to the sun is proportional to the
time."[4] He was much aided in his measurements by the use of a system
of logarithms invented by John Napier (1614). Many measurements were
established regarding heat, pressure of air, and the relation of solids
and liquids.

Isaac Newton, by connecting up a single phenomenon of a body falling a
distance of a few feet on the earth with all similar phenomena, through
the law of gravitation discovered the unity of the universe. Though
Newton carried on important investigations in astronomy, studied the
refraction of light through optic glasses, was president of the Royal
Society, his chief contribution to the sciences was the tying together
of the sun, the planets, and the moons of the solar system by the
attraction of gravitation. Newton was able to carry along with his
scientific investigations a profound reverence for Christianity. That
he was not attacked shows that there had {464} been considerable
progress made in toleration of new ideas. With all of his greatness of
vision, he had the humbleness of a true scientist. A short time before
his death he said: "I know not what I may appear to the world; but to
myself I seem to have been only like a boy playing on the seashore, and
diverting myself in now and then finding a smoother pebble, or a
prettier shell, than ordinary, whilst the great ocean of truth lay all
undiscovered before me."

_Science Develops from Centres_.--Bodies of truth in the world are all
related one to another. Hence, when a scientist investigates and
experiments along a particular line, he must come in contact more or
less with other lines. And while there is a great differentiation in
the discovery of knowledge by investigation, no single truth can ever
be established without more or less relation to all other truths.
Likewise, scientists, although working from different centres, are each
contributing in his own way to the establishment of universal truth.
Even in the sixteenth century scientists began to co-operate and
interchange views, and as soon as their works were published, each fed
upon the others as he needed in advancing his own particular branch of
knowledge.

It is said that Bacon in his _New Atlantis_ gave such a magnificent
dream of an opportunity for th