Page:A Voyage of Discovery and Research in the Southern and Antarctic Regions Vol 2.djvu/384

342 Cockburn Island is too feeble to melt the ice immediately beneath them; and the air was so dry during our visit, that Daniell's Hygrometer, placed hardly six inches above the ice and on the stones, indicated twenty-two degrees of difference on one occasion; and upon another, it fell from 40° to 13°, without producing any condensation. Such dryness is eminently injurious to all vegetables but lichens, which, in many cases, seem to thrive best under excessive atmospheric changes. The preponderance of the Lecanora in Cockburn Island cannot arise from this exsiccation stimulating its growth; but may be caused by the reaction that takes place afterwards, on the rapid condensation of vapour previously heated by the temperature of the rocks upon which it grows."

Our observations place this island in latitude 64° 12′ S., longitude 59° 49′ W. The tide was falling during the whole time we were on shore, and it was low water at apparent noon; the stream setting out of the inlet to the northward; and judging from the well defined high-water mark, the amount of rise and fall was not more than six feet. The observations were made on a beach, near the north point of the island. This beach is probably the favourite resort of the fur seals at the proper season of the year, and is admirably adapted to their wants. Besides penguins and cormorants innumerable, we found the beautiful white petrel building its nest in the precipitous cliffs, above the