Michel Devouasson of Chamouni fell into a crevasse on the Glacier
of Talefre, a feeder of the Mer de Glace, on the 29th of July 1836,
and after a severe struggle extricated himself, leaving his knapsack
below. The identical knapsack reappeared in July 1846, at a spot on
the surface of the glacier _four thousand three hundred_ feet from
the place where it was lost, as ascertained by Professor Forbes, who
himself collected the fragments; thus indicating the rate of flow of
the icy river in the intervening ten years.--_Quarterly Review_, No.
202.