s
easily led the world in astronomy, mechanics, and mathematics.

The science of algebra is generally attributed to the Arabians. Its
name is derived from gabara, to bind parts together, and yet the origin
of this science is not certain. It is thought that the Arabs derived
their knowledge from the Greeks, but in all probability algebra had its
first origin among the philosophers of India.

The Arabians used geometry, although they added little to its
advancement. Geometry had reached at this period an advanced stage of
progress in the problems of Euclid. It was to the honor of the
Arabians that they were the first of any of the Western peoples to
translate Euclid and use it, for it was not until the sixteenth century
that it was freely translated into the modern languages.

But in trigonometry the Arabians, by the introduction of the use of the
sine, or half-chord, of the double arc in the place of the arc itself,
made great advancement, especially in the calculations of surveying and
astronomy. In the universities and colleges of Spain under Arabian
dominion we find, then, that students had an opportunity of mastering
nearly all of the useful elementary mathematics. Great attention was
paid to the study of astronomy. Here, as before, they used the Greek
knowledge, but they advanced the study of the science greatly by the
introduction of instruments, such as those for measuring time by the
movement of the pendulum and the measurement of the heavenly bodies by
the astrolabe.

Likewise they employed the word "azimuth" and many other terms which
show a more definite knowledge of the relation of the heavenly bodies.
They were enabled, also, to {312} measure approximately a degree of
latitude. They knew that the earth was of spheroid form. But we find
astrology accompanying all this knowledge of astronomy. While the
exact knowledge of the heavenly bodies had been developed to a certain
degree, the science of star influence, or astrology, was cultivated to
a still greater extent. Thus they sought to show the control of mind
forces on earth, and, indeed, of all natural forces by the heavenly
bodies. This placed mystical lore in the front rank of their
philosophical speculations.

_Geography and History_.--In the study of the earth the Arabians showed
themselves to be practical and accurate geographers. They applied
their mathematical and astronomical knowledge to the study of the
earth, and thus gave an imp