The Yosemite eBook

weighing chances of escape.  Would the column be swayed a few inches away from the wall, or would it come yet closer?  The fall was in flood and not so lightly would its ponderous mass be swayed.  My fate seemed to depend on a breath of the “idle wind.”  It was moved gently forward, the pounding ceased, and I was once more visited by glimpses of the moon.  But fearing I might be caught at a disadvantage in making too hasty a retreat, I moved only a few feet along the bench to where a block of ice lay.  I wedged myself between the ice and the wall and lay face downwards, until the steadiness of the light gave encouragement to rise and get away.  Somewhat nerve-shaken, drenched, and benumbed, I made out to build a fire, warmed myself, ran home, reached my cabin before daylight, got an hour or two of sleep, and awoke sound and comfortable, better, not worse for my hard midnight bath.

Climate And Weather

Owing to the westerly trend of the Valley and its vast depth there is a great difference between the climates of the north and south sides—­greater than between many countries far apart; for the south wall is in shadow during the winter months, while the north is bathed in sunshine every clear day.  Thus there is mild spring weather on one side of the Valley while winter rules the other.  Far up the north-side cliffs many a nook may be found closely embraced by sun-beaten rock-bosses in which flowers bloom every month of the year.  Even butterflies may be seen in these high winter gardens except when snow-storms are falling and a few days after they have ceased.  Near the head of the lower Yosemite Fall in January I found the ant lions lying in wait in their warm sand-cups, rock ferns being unrolled, club mosses covered with fresh-growing plants, the flowers of the laurel nearly open, and the honeysuckle rosetted with bright young leaves; every plant seemed to be thinking about summer.  Even on the shadow-side of the Valley the frost is never very sharp.  The lowest temperature I ever observed during four winters was 7 degrees Fahrenheit.  The first twenty-four days of January had an average temperature at 9 A.M. of 32 degrees, minimum 22 degrees; at 3 P.M.

the average was 40 degrees 30’, the minimum 32 degrees.  Along the top of the walls, 7000 and 8000 feet high, the temperature was, of course, much lower.  But the difference in temperature between the north and south sides is due not so much to the winter sunshine as to the heat of the preceding summer, stored up in the rocks, which rapidly melts the snow in contact with them.  For though summer sun-heat is stored in the rocks of the south side also, the amount is much less because the rays fall obliquely on the south wall even in summer and almost vertically on the north.

The upper branches of the Yosemite streams are buried every winter beneath a heavy mantle of snow, and set free in the spring in magnificent floods.  Then, all the fountains, full and overflowing, every living thing breaks forth into singing, and the glad exulting streams shining and falling in the warm sunny weather, shake everything into music making all the mountain-world a song.