Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

1835. GALAPAGOS ISLANDS. 485 considerable — we were anxiously looking out for land, when what appeared to be an islet was seen from the mast-head. This seeming islet turned out to be the summit of Mount Pitt, a remarkable hill at the north-east end of Chatham Island. (Charles Island of Cowley, 1684). As the breeze and current carried us onwards, the tops of other hills successively appeared, and for a short time looked very like a cluster of islets. Gradually rising above the horizon, the greater part of Chatham Island became distinctly visible : in this neighbour- hood it is not often that the air near the water is clear enough to allow of very distant high land being thus gradually raised above the horizon of an eye at the mast-head ; for, in general, clouds hang about these islands, and the atmosphere itself is hazy. Towards evening the higher parts of the land were clouded over, but we were near enough to see that the island was very rugged — in some places quite barren — in others covered with a stunted and sun-dried brushwood — and that the heights, on which the clouds hung, were thickly clothed with green wood. The shores seemed to be bold, and easy to approach, though not to land upon, because of a continual high surf. A number of little craters (as they appeared to be) and huge irregular-shaped masses of lava rock, gave a strangely misleading appearance to the lower parts of the island ; and when first seen through that indistinct glimmer which is usually noticed over land on which a hot sun is shining, were supposed to be large trees and thick wood.* Hood Island, small and rather low, was seen before dusk, when we tacked and stretched to seaward for a few hours. 16th. Assisted by a current running to the westward, we worked up to Hood Island during the night, and at day- light lowered a boat down and prepared her for Mr. Chaffers, • This glimmering haziness is at times a great impediment to making accurate measurements of an object, when both it and the observer's eye are near the ground. Raising either some few feet higher, remedies this inconvenience, which is much felt when using a micrometer for measur- ing a base.