Cu. XV.] 



FLOOD IN THE VALLEY OF BAGNES. 



353 



the winter season, during continued frost, scarcely any water 

 flows in the bed of this river to preserve an open channel, so 



meltin 



& 



snow in spring, when a lake was formed above, about half 



which finally attained in some parts 



league in length, 



a depth of about 200 feet, and a width of about 700 feet. 

 To prevent or lessen the mischief apprehended from the 

 sudden bursting of the barrier, an artificial gallery, 700 

 feet in length, was cut through the ice, before the waters 



had risen to a great height. 



When 



flow through the tunnel, they 



such an elevation as to 

 dissolved the ice, and thus deepened their channel, until 

 nearly half of the whole contents of the lake were slowly 

 drained off. But at length, on the approach of the hot 



mass 



season, the central portion of the remaining 

 way with a tremendous crash, and the residue of the lake was 

 emptied in half an hour. In the course of their descent, the 

 waters encountered several narrow gorges, and at each of 

 these they rose to a great height, and then burst with new 

 violence into the next basin, sweeping along rocks, forests, 

 houses, bridges, and cultivated land. For the greater part 

 of its course the flood resembled a moving mass of rock and 

 mud, rather than of water. Some fragments of granitic 



enormous 



o 



mi 



compar 



were torn out of a more ancient alluvion, and borne down for 



mile 



•ments moved 



paces in circumference. * The velocity of the water, in the 

 first part of its course, was thirty-three feet per second, which 

 diminished to six feet before it reached the Lake of Geneva, 

 where it arrived in six hours and a half, the distance bein 



t 



Marti 



sands of trees torn up by the roots, together with the ruins 

 of buildings. Some of the houses in that town were filled 



up to the second story. After expanding in the 



mud 



* This block was measured by Capt. in 1818, Ed. Phil. Journ., vol. i. p. 187, 



P>. Hall, E. N. 



t Inundation of the Val de Bagnes, 



from memoir of M. Escher. 



VOL. I. 



A A 



