ively sure that he had already set foot upon it in 1492
and 1494.]

[Footnote 595: A modern traveller thus describes this river:
"Right and left of us lay, at some distance off, the low banks
of the Apure, at this point quite a broad stream. But before us
the waters spread out like a wide dark flood, limited on the
horizon only by a low black streak, and here and there showing
a few distant hills. This was the Orinoco, rolling with
irrepressible power and majesty sea-wards, and often upheaving
its billows like the ocean when lashed to fury by the wind....
The Orinoco sends a current of fresh water far into the ocean,
its waters--generally green, but in the shallows
milk-white--contrasting sharply with the indigo blue of the
surrounding sea." Bates, _Central America, the West Indies, and
South America_, 2d ed., London, 1882, pp. 234, 235. The island
of Trinidad forms an obstacle to the escape of this huge volume
of fresh water, and hence the furious commotion at the two
outlets, the Serpent's Mouth and Dragon's Mouth, especially in
July and August, when the Orinoco is swollen with tropical
rains.]

[Footnote 596: In Columbus's own words, in his letter to the
sovereigns describing this third voyage, "Y digo que ... viene
este rio y procede de tierra infinita, pues al austro, de la
cual fasta agora no se ha habido noticia." Navarrete,
_Coleccion_, tom. i. p. 262.]

[Illustration: Discoveries made by Columbus in his third and fourth
voyages.]

[Sidenote: Speculations as to the earth's shape.]

[Sidenote: The mountain of Paradise.]

In spite of the correctness of this surmise, Columbus was still as far
from a true interpretation of the whole situation as when he supposed
Hispaniola to be Ophir. He entered upon a series of speculations which
forcibly remind us how empirical was the notion of the earth's rotundity
before the inauguration of physical astronomy by Galileo, Kepler, and
Newton. We now know that our planet has the only shape possible for such
a rotating mass that once was fluid or nebulous, the shape of a spheroid
slightly protuberant at the equator and flattened at the poles; but this
knowledge is the outcome of mechanical principles utterly unknown and
unsuspected in the days of Columbus. He un