ulse to exploration. While their theories
of the origin of the earth were crude and untenable, their practical
writings on the subject derived from real knowledge, and the practical
instruction in schools by the use of globes and maps, were of immense
practical value.

Their history was made up chiefly of the histories of cities and the
lives of prominent men. There was no national history of the rise and
development of the Arabian kingdom, for historical writing and study
were in an undeveloped state.

_Discoveries, Inventions, and Achievements_.--It cannot be successfully
claimed that the Arabians exhibited very much originality in the
advancement of the civilized arts, yet they had the ability to take
what they found elsewhere developed by other scholars, improve upon it,
and apply it to the practical affairs of life. Thus, although the
Chinese discovered gunpowder over 3,000 years ago, it remained for the
Arabs to bring it into use in the siege of Mecca in the year 690, and
introduce it into Spain some years later. The Persians called it
Chinese salt, the Arabians Indian snow, indicating that it might have
originated in different countries. The Arab-Moors used it in their
wars with the Christians as early as the middle of the thirteenth
century. They excelled also in making paper from flax, or cotton,
which was probably an imitation {313} of the paper made by the Chinese
from silk. We find also that the Arabs had learned to print from
movable type, and the introduction of paper made the printing-press
possible. Linen paper made from old clothes was said to be in use as
early as 1106.

Without doubt the Arab-Moors introduced into Spain the use of the
magnet in connection with the mariner's compass. But owing to the fact
that it was not needed in the short voyages along the coast of the
Mediterranean, it did not come into a large use until the great voyages
on the ocean, in the beginning of the fourteenth century. Yet the
invention of the mariner's compass, so frequently attributed to Flavio
Giorgio, may be as well attributed to the Arab-Moors.

Knives and swords of superior make, leather, silk, and glass, as well
as large collections of delicate jewelry, show marked advancement in
Arabian industrial art and mechanical skill.

One of the achievements of the Arab-Moors in Spain was the introduction
of agriculture, and its advancement to an important position among the
industries by means of irrigation.