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 we