Page:Walcott A Geologists Paradise.djvu/7

From Wikisource
Jump to navigation Jump to search
This page has been validated.
A GEOLOGIST'S PARADISE
515

well shown by the photograph of Mount Huber, on page 518.

Photo by Charles D. Walcott
A COOL SEPTEMBER MORNING AT 7,000 FEET ABOVE SEA-LEVEL.

An illustration of a long summit ridge is given by Mount Daly, where every summer storm leaves a fresh coating of snow. I well recall stepping off that limestone onto the snow, thinking it hard and secure, and dropping in up to my armpits within a few feet of the rock. We were glad to paddle our way back and follow the rocky ridge for miles around to get back to camp.

Some of the deep canyons were filled up for 1,000 feet or more by dirt, gravel and boulders washed down from the sides of the mountains, probably during the great Glacial period. Upon the withdrawal of the ice this accumulated material was rapidly cut away, but occasionally masses of it are left high on the sides of a mountain, and often most fantastic forms result from its erosion where the finer beds of gravel and clay are hardened and protected above by blocks of sandstone and limestone. One of the most noteworthy examples is that of the so-called Hoodoos, on the slope of Mount Vaux, 18 miles west of Field.


TAKING THE PHOTOGRAPHS

The panoramic photographs were taken with the Cirkut camera that is used by newspaper men and others for photographing processions and obtaining panoramic views of buildings, railway lines, etc. For use in the mountains several minor changes were made, so that the instrument could be used successfully under such adverse conditions as strong winds, hands and fingers numbed from cold, and often very insecure foundation for the tripod. As it is necessary to have absolute stability and the camera-bed level, the securing of perfect negatives is difficult.

The camera consists of the ordinary 6½ by 8½ outfit, with a panoramic attachment which is 10½ inches square by