Note 3 — STEPPES AND DESERTS.

p. 2.—“We seem to see before us a shoreless ocean.”

The prospect of the distant Steppe is still more striking, when the spectator has been long accustomed in the dense forests both to a very restricted field of view, and to the aspect of a rich and highly luxuriant vegetation. Ineffaceable is the impression which I received on our return from the Upper Orinoco, when, from the Hato del Capuchino, on a mountain opposite to the mouth of the Rio Apure, we first saw again the distant Steppe. The sun had just set; the Steppe appeared to rise like a hemisphere; and the light of the rising stars was refracted in the lowest stratum of air. The excessive heating of the plain by the vertical rays of the sun causes the variations of refraction,—occasioned by the effects of radiation, of the ascending current, and of the contact of strata of air of unequal density,—to continue through the entire night.