all as clear about
their geographical postulates as about their theological or ethical
rules. And what concerns us here is that they exactly reflect the mind
of the Arabic science or pseudo-science of the time just preceding, so
that their words may represent to us the state of Mohammedan thought
between the eighth and twelfth centuries, between the writers at the
Court of Caliph Almamoun (813-833) and Edrisi at the Court of King Roger
of Sicily (1150).

(1.) _Adelard_, summarising Mohammed Al-Kharizmy with the results of his
Paris education, tells us of the Arabic "Examination of planets and of
time, starting from the centre of the world, called _Arim_, from which
place to the four ends of the earth the distance is equal, viz., ninety
degrees, answering to the fourth part of the world's circumference. It
is tedious and unending to attempt to place all the countries of the
world and to fix all the marks of time. So the meridian is taken as the
measure of the latter and _Arim_ of the former, and from this
starting-point it is not hard to fix other countries." "Arim," he
concludes, "is under the equator, at the point where there is no
latitude," and he plainly implies that there were then existing among
the Arabs tables calculating all the chief places of every country from
the meridian of _Arim_.

(2.) _Gerard_ of Cremona, who, though for some time a resident at
Toledo, is essentially an Italian, tells us about the "Middle of the
World," from which longitudes were calculated, "called Arim," and "said
to be in India," whose longitude from west to east or from east to west
is ninety degrees.

In his _Theory of the Planets_ Gerard tells us still more wonderful
things. Arim was a geographical centre known and used by Hermes
Trismegistus and by Ptolemy, as well as by the great Arab geographers;
Alexander of Macedon marched just as far to the east of Arim as Hercules
to the west; both reached the encircling ocean, and accordingly "Arim
is equidistant from both the Gades, 90 degrees; likewise from each pole,
north and south, the same, 90 degrees." This all recurs in the tables of
Alphonso the Wise of Castille about A.D. 1260, and two of the greatest
of mediaeval thinkers, Albert and Roger Bacon, reproduced the essential
points of this doctrine, its false symmetry, and its balance of the true
and the traditional, with variations of their own.

(3.) _Albert the Great_, Albertus Magnus, second only to Aquinas among
the Conti