GLACIER BAY.                       101
it is believed, some 900 ft. below the surface of the sea in a long, ploughshaped forefoot. The vast ice plain slopes back at a grade of 100 ft. to the mile to the mountains, 10 and 13 miles distant from the inlet. The Muir Glacier, 58° 50' N., and 1360 5' W., drains an area of 800 square miles. The actual ice surface covers about 350 square miles, the mass of it 35 miles long and 10 to 15 miles wide, lying but a few hundred feet above sea-level. It is fed by 26 tributary streams, 7 of which are over a mile in width. If all their affluents were named and counted, as in Switzerland, the Muir might boast 200 branches or glaciers in its system. The mountain gateway, 21 miles wide, through which it pours to the sea, is formed by spurs of Mt. Case (5,510 ft.) and Mt. Wright (4,944 ft.) on the E., and a spur of the sharply cut Pyramid Peak on the W. All the mountains immediately surrounding the glacier average from 4,000 to 6,000 ft. in height. The main stream of the Muir flows from the N. W., rising in neves 40 miles distant. The main current of this magnificently crevassed and broken ice pours through the great plain at a rate of 8 to 10 ft. a day. All efforts to cross it within 10 miles back from the water front have failed." *
Seven medial moraines stretch away in dark fan-rib lines from the front, rising in terraces on the ice and indicating the course and source of chief tributaries. Lateral moraines extend in crumbling bluffs and gravel terraces for 3 miles down either side of the inlet.
Ships do not approach the ice wall nearer than an eighth of a mile, because of the masses of ice falling from its face with terrific noise and agitation of the water, and of submarine bergs detached from the sunken forefoot and rising to the surface with tremendous force. Soundings of 86 and 120 fathoms have been made within 100 yards of
* Of the Norwegian glaciers, which may be most fairly used for comparison with the Muir, the Jostedalbrae, the largest glacier in Europe, lies 3° N. of the Muir, at an elevation of 3,000 ft. above the sea, and covers 470 square miles. It is an ice-cap on the top of a range, with five arms flowing down and one reaching within 150 ft. of sea-level. The Svartisen, the show glacier of the Norway coast, 8° N. of the Muir, and on the line of the Arctic Circle, is an ice mantle 44 miles long and 12 to 25 miles wide, occupying a plateau 4,000 ft. above the sea. The arm in Meld, visited by North Cape tourists, does not reach tide-water. The Swiss glaciers, all lying from 4,000 and 6,000 ft. above the sea are like those of Mt. Rainier, and in no way to be compared to the Muir, 20 of whose arms each exceed the Mer de Glace in size.