He says: "To the south the calm surface of the bay opened outward into Cross Sound twenty-five miles away. The islands dotting the smooth surface of the waters below us seemed but specks, and the grand vista of snowclad mountains guarding either side of Chatham Strait seemed gradually to come to a point on the southern horizon. Westward toward the Pacific was the marvelous outline of the southern portion of the St. Elias Alps. The lofty peaks of Crillon, 15,900 feet high, and Fair Weather, 15,500 feet high, about twenty-five miles away and about the same distance apart, stood as sentinels over the lesser peaks."
The Muir glacier might be likened to a great inland sea of ice fed by many tributaries or ice rivers. It narrows up at the point where it empties into Muir Inlet to 10,664 feet, or a little over two miles. An enormous pressure is exerted at this point, which causes the ice to flow in the central portion at the rate of about seventy feet per day. There is a continual booming, like the firing of a cannon, going on, caused by the bursting of some great iceberg either before it takes its final leap into the water or at the moment of its fall. At the point where these great icebergs drop off into the water they stand like a solid wall 300 feet above its surface. Dr. Wright says: "From this point there is a constant succession of falls of ice into the water, accompanied by loud reports. Scarcely ten minutes, either night or day, passed during the whole month without our being startled with such reports; and frequently they were like thunder claps or the booming of cannon at the bombardment of a besieged city, and this though our camp was two and one-half miles below the ice front.... Repeatedly I have seen vast columns of ice extending up to the full height of the front topple over and fall into the water. How far these columns extended below the water could not be told accurately, but I have seen bergs floating away which were certainly 500 feet in length."
It is estimated that the cubical contents of some of these icebergs are equal to 40,000,000 feet. This great glacier is fed by the constant precipitation of snow upon the sides and peaks of the high mountains that surround its vast amphitheater, which is floored with icebergs. Wonderful as this seems to us to-day, it is scarcely a microscopic speck of what existed during the ice age all over the northern part of North America.