In crossing the Lucia glacier we experienced the usual difficulties met with on the débris-covered ice-field of Alaska. The way was exceedingly rough, on account of the ridges and valleys on the ice, and on account of the angular condition of the débris resting upon it. Many of the ridges could not conveniently be climbed, owing to the uncertain footing afforded by the angular {106} stones resting on the slippery slope beneath. Fortunately, the crevasses were mostly filled with stones fallen from the sides, so that the danger from open fissures, which has usually to be guarded against in glacial excursions, was obviated; yet, as is usually the case when crevasses become filled with débris, the melting of the adjacent surfaces had caused them to stand in relief and form ridges of loose stones, which were exceedingly troublesome to the traveler. [Illustration: PLATE 12. ENTRANCE TO AN ICE TUNNEL; FORMERLY THE OUTLET OF A GLACIAL LAKE.] Near the western side of the Lucia glacier, between Terrace point and Floral pass, there is a huge rounded dome of sandstone rising boldly out of the ice. This corresponds to the "nunataks" of the Greenland ice-fields, and was covered by ice when the glaciation was more intense than at present. On the northern side of the island the ice is forced high up on its flanks, and is deeply covered with moraines; but on the southwestern side its base is low and skirted by a sand plain deposited in a valley formerly occupied by a lake. The melting of the glacier has, in fact, progressed so far that the dome of rock is free from ice on its southern side, and is connected with the border of the valley toward the west by the sand plain. This plain is composed of gravel and sand deposited by streams which at times became dammed lower down and expanded into a lake. Sunken areas and holes over portions of the lake bottom show that it rests, in part at least, upon a bed of ice. [Illustration: PLATE 13. DELTAS IN AN ABANDONED LAKE BED.] The most novel and interesting feature in the Lucia glacier is a glacial river which bursts from beneath a high archway of ice just at the eastern base of the nunatak mentioned above, and flows for about a mile and a half through a channel excavated in the ice, to then enter the mouth of another tunnel and become lost to view. An illustration of this strange river and of the mouth of the tunnel in the débris-covered ice into which it rolls, reproduced from a photograph by a mechanical process, is given on plate 14, and another view of the mouth of the same tunnel is presented in the succeeding plate. This is the finest example of a glacial river that it has ever been my good fortune to examine. [Illustration: PLATE 14. A RIVER ON THE LUCIA GLACIER.]