In his December 1872 Overland Monthly article, "Living Glaciers of California" he wrote, "On the twenty-first of August last, I planted five stakes in the glacier of Mt. McClure. Four of these stakes were extended across the glacier, in a straight line, from the ease side to a point near the middle of the glacier. The positions of these stakes were determined by sighting across from bank to bank, past a plumb-line, made of a stone and a black horse-hair. On observing my stakes on the sixth of October, or in forty-six days after being planted, I found that stake No.1 had been carried downstream eleven inches; No.2, eighteen inches; No.3, thirty-four, and No.4, forty-seven inches. As stake No.4 was near the middle of the glacier, perhaps it was not far from the point of maximum velocity -- forty-seven inches in forty-six days, or one inch per day. Thus these ice-masses are seen to possess the true glacial motion." (John Muir Papers, December 1872 Overland Monthly "Living Glaciers of California")
For more information...
Read Geology Underfoot in Yosemite National Park, 2010 by Allen F. Glazner and Greg M. Stock.
Questions or Comments?