After having, as
successfully as his means and the state of the science would permit him to
do, fixed the position of the stars, he transferred the method which he had
employed for this purpose to geography: he was the first who determined the
situation of places on the earth, by their latitudes and longitudes, with
any thing like accuracy. The latitude, indeed, of many places had been
fixed before; and the means of doing it were sufficiently simple and
obvious: but with respect to some general and safe mode of ascertaining the
longitudes, the ancient philosophers before Hipparchus, were ignorant of
it. He employed for this purpose the eclipses of the moon. After having
ascertained the latitudes and longitudes of a great many places, he
proposed to draw up a catalogue of terrestial latitudes and longitudes, but
this he was not able to accomplish: he had set the example, however and it
was followed by subsequent astronomers. He fixed on the Fortunate Islands,
which are supposed to be the Canaries, for his first meridian. His
principal works most probably were destroyed in the conflagration of the
Alexandrian library. His catalogue of the stars is preserved in the
Almagest of Ptolemy; and his commentary on Aratus and Eudoxus is still
extant.
Such is a brief sketch of the advantages which geography, as founded on
astronomy, derived from the labours of Hipparchus.
Pages:
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189