The intelligent observer, Peter Martyr de Aughiera, one of the
friends of Christopher Columbus, seems to have been the first who recognized
(in the expedition undertaken by Rodrigo Enrique Colmenares, in October,
1510) that the limit of perpetual snow continues to ascend as we approach
the equator. We read, in the fine work 'De Rebus Oceanicis',* "the River
Gaira comes from a mountain in the Sierra Nevada de Santa Maria, which,
according to the testimony of the companions of Colmenares, is higher than
any other mountain hitherto discovered.
[footnote] *Anglerius, 'De Rebus Oceanicis', Dec. xi., lib. ii., p. 140
(ed. Col., 1574). In the Sierra de Santa Marta, the highest point of which
appears to exceed 19,000 feet (see my 'Relat. Hist.', t. ii., p. 214), there
is a peak that is still called Pico de Gaira.
It must undoubtedly be so if 'it retain snow perpetually' in a zone which is
not more than 10 degrees from the equinoctial line." The lower limit of
perpetual snow, in a given latitude, is the lowest line at which snow
continues during summer, or, in other words, it is the maximum of height to
which the snow-line recedes in the course of the year. But this elevation
must be distinguished from three other phenomena, namely, the annual
fluctuation of the snow-line, the occurrence of sporadic falls of snow, and
the existence of glaciers, which appear to be peculiar to the temperate and
cold zones.
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