Page:Alaska days with John Muir.djvu/191

Rh so vast and so comparatively still that it has but few crevasses, and Muir's day for traversing it was a perfect one—warm and sunny. Another day he and I climbed the mountain that overlooked it and skirted the mighty ice-field for some distance, then walked across the face of the glacier just back of the rapids, keeping away from the deep crevasses. We drove a straight line of stakes across the glacial stream and visited them each day to watch the deflection and curves of the stakes, and thus arrive at some conception of the rate at which the ice mass was moving. In some parts of the glacial stream this ice current flowed as fast as fifty or sixty feet a day, and we could understand the constant breaking off and leaping up and smashing down of the ice and the formation of that great mass of bergs.