Outlines of the Earths History | Page 6

ears; also that in many instances the sense of touch conveys
information which extends our perceptions in many important ways;
but science rests practically on sight, and on the insight that comes
from the training of the mind which the eyes make possible.
The early inquirers had no resources except those their bodies afforded;
but man is a tool-making creature, and in very early days he began to
invent instruments which helped him in inquiry. The earliest deliberate
study was of the stars. Science began with astronomy, and the first
instruments which men contrived for the purpose of investigation were
astronomical. In the beginning of this search the stars were studied in
order to measure the length of the year, and also for the reason that they
were supposed in some way to control the fate of men. So far as we
know, the first pieces of apparatus for this purpose were invented in
Egypt, perhaps about four thousand years before the Christian era.
These instruments were of a simple nature, for the magnifying glass
was not yet contrived, and so the telescope was impossible. They
consisted of arrangements of straight edges and divided circles, so that

the observers, by sighting along the instruments, could in a rough way
determine the changes in distance between certain stars, or the height of
the sun above the horizon at the various seasons of the year. It is likely
that each of the great pyramids of Egypt was at first used as an
observatory, where the priests, who had some knowledge of astronomy,
found a station for the apparatus by which they made the observations
that served as a basis for casting the horoscope of the king.
In the progress of science and of the mechanical invention attending its
growth, a great number of inventions have been contrived which vastly
increase our vision and add inconceivably to the precision it may attain.
In fact, something like as much skill and labour has been given to the
development of those inventions which add to our learning as to those
which serve an immediate economic end. By far the greatest of these
scientific inventions are those which depend upon the lens. By
combining shaped bits of glass so as to control the direction in which
the light waves move through them, naturalists have been able to create
the telescope, which in effect may bring distant objects some thousand
times nearer to view than they are to the naked eye; and the microscope,
which so enlarges minute objects as to make them visible, as they were
not before. The result has been enormously to increase our power of
vision when applied to distant or to small objects. In fact, for purposes
of learning, it is safe to say that those tools have altogether changed
man's relation to the visible universe. The naked eye can see at best in
the part of the heavens visible from any one point not more than thirty
thousand stars. With the telescope somewhere near a hundred million
are brought within the limits of vision. Without the help of the
microscope an object a thousandth of an inch in diameter appears as a
mere point, the existence of which we can determine only under
favourable circumstances. With that instrument the object may reveal
an extended and complicated structure which it may require a vast
labour for the observer fully to explore.
Next in importance to the aid of vision above noted come the scientific
tools which are used in weighing and measuring. These balances and
gauges have attained such precision that intervals so small as to be
quite invisible, and weights as slight as a ten-thousandth of a grain, can

be accurately measured. From these instruments have come all those
precise examinations on which the accuracy of modern science
intimately depends. All these instruments of precision are the
inventions of modern days. The simplest telescopes were made only
about two hundred and fifty years ago, and the earlier compound
microscopes at a yet later date. Accurate balances and other forms of
gauges of space, as well as good means of dividing time, such as our
accurate astronomical clocks and chronometers, are only about a
century old. The instruments have made science accurate, and have
immensely extended its powers in nearly all the fields of inquiry.
Although the most striking modern discoveries are in the field which
was opened to us by the lens in its manifold applications, it is in the
chemist's laboratory that we find that branch of science, long cultivated,
but rapidly advanced only within the last two centuries, which has done
the most for the needs of man. The ancients guessed that the substances
which make up the visible world were more complicated in their
organization than they appear to our