The Mount Lyell was selected principally on account of its comparative ease of access. group of mountains of which it is one of the dominating points stands at the southern extremity of what may be called the "northern high Sierra," or that part of the crest of the great range lying between the headwaters of the Mokelumne River and those of the North Fork of the San Joaquin. In passing south along the high Sierra the summit peaks become progressively higher and more rugged, and the area above the timber line more extensive. About the head of the Merced River the northern portion culminates in a magnificent pile of snow capped peaks extending between Mounts Lyell and Ritter, where the southernmost glaciers of the range are to be found. South of Mount Ritter the crest breaks down in a wide belt of rolling, forest-covered mountains for nearly 20 miles, but rises again finally at Red Slate Peak. South of this the extends as an unbroken wilderness of alpine peaks, rugged beyond description, culminating a second time in Mount Whitney, about 100 miles south of Lyell. This latter is the high Sierra par excellence. range On July 8, 1897, minimum thermometer No. 4315 of the United States Weather Bureau was left upon the summit. It was inclosed in a thin wooden box about 6 inches square and 2 feet long, one side of which was laid exactly in line with the edge of the great southern precipice, here over 1,500 feet high. Large stones were laid upon it, but one side was exposed to the weather, and in no way could it become entirely covered with snow. On June 5, 1898, the mountain was revisited, and the thermometer box was carefully uncovered. The thermometer was in perfect condition, and registered -13.6 F., -25° C. It was reset and left upon the mountain a second year. Professor Le Conte was unable to make the ascent of the mountain in 1899, but Prof. H. I. Randall, of the civil engineering department of the State University, visited the spot in July and obtained the reading. In this case it was -17.6° F. It will be remembered that the winter of 1897-98 was an exceptionally dry one, and that of 1898-99 was not severe. It is interesting to compare these temperatures with those taken a few miles farther east and many thousand feet lower: It would be instructive to obtain the minimum winter temperatures of a number of high peaks distributed along the crest of the range from Lake Tahoe to Mount Whitney. 1887. 1.66 9.41 0.98 1888. 5.84 1.92 4.50 1889. 0.78 0.54 7.58 1890. 11.16 5.70 4.74 1891. 1.13 10.68 1892. 2.53 0.06 0.04 0.01 0.00 0.30 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 1894. 3.30 1.40 1895. 5.28 3.10 1896. 2.53 0.25 1897. 1898. 1899. 0.28 1900. 1.75 2.35 1.60 0.20 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.60 0.00 0.00 0.00 0.00 1.33 2.18 7.83 1.05 3.65 10.59 9.94 9.42 10.60 11.31 13.14 |