176 MATHEMATICAL GEOGRAPHY. [CHAP.
stadia for the circumference of the earth—or rather 252,000, that
modification having been adopted with a view to greater con-
venience in division—and this he subdivided into 360 degrees of
700 stadia each. Then, taking the meridian line through Meroe
and the mouth of the Borysthenes, he divided the fourth part of
this circle which intervened between the equator and the pole,
into sections of 700 stadia each, and drew parallels corresponding
to them. The spaces on the earth's surface which intervened
between these parallels, and each of which was equal to a degree
of latitude, he called climata—a term which was afterwards ap-
plied to the temperature of those areas, and thus assumed the
sense in which 'climate' is used at the present day. He also
described the changes in the position of the objects in the celestial
sphere which corresponded to each of these degrees, proceeding
northwards from the equator1. This scheme, it will be perceived,
was purely mathematical, and was determined independently of
the position of places on the earth's surface; but after drawing
out this table of parallels, Hipparchus proceeded to mark upon it
those places, the latitude of which had been determined by
astronomical observations—that is, by reckoning the number of
the hours of the longest day. A plan such as .this, however,
though it might be theoretically perfect, required, in order to
apply it in practice, a larger amount of information than that
age could furnish. Nothing less than the combined action of a
number of scientific associations at various stations, whose
members might observe the movements of the heavenly bodies,
and after comparing them might note the results on Hipparchus'
tables, together with an organised system of collecting informa-
tion from travellers, merchants and others, whose employments
led them into distant lands, could have made a map constructed
on such principles anything'more than an arrangement of lines
diversified with scattered names. ' These conditions, it need
hardly be said, were not forthcoming, and the excessiveness of
the claim which the" scheme of Hipparchus involved stood in
the way of even its partial realisation. It may have served to
point out to men of science at a later period the true method
to be followed, but for the time it discouraged the study of
1 Strabo, 2. 5, 34. . .