252 



THE MUSEUM. 



■intention is to discuss a point on 

 which both these writers seem to be 

 behind the knowledge of the day — 

 namely, the manner in which these 

 wonderful ravines have been formed. 

 Mr. Martel argues, and Mr. Gould 

 takes it for granted, that the canons 

 were originally subterranean water- 

 courses, and that the caverns formed 

 by these underground waters became 

 open valleys by the falling of their 

 roofs. This idea has commended it- 

 self to other travelers, and is even 

 shared by some who have a consider- 

 able knowledge of geological causes. 

 It is a possible explanation, and look- 

 ing to the canons alone, without con- 

 sidering the valleys beyond and below 

 them, it might seem a reasonable way 

 of accounting for their e.xistence; but 

 it is not the way in which the other 

 gorges and canons have been formed, 

 and there is no reason that I can learn 

 why these should have been formed 

 in so exceptional a manner. 



A few decades ago it was generally 

 supposed that such deep ravines were 

 simply cracks in the earth's crust, and 

 travellers described them as resulting 

 from some "great convulsion of na- 

 ture," laying stress on the fact that 

 every concavity on one side was op- 

 posed by a convexity or promontory 

 on the other, and taking it for grant- 

 ed that the two walls had originally 

 fitted into one another and had simply 

 gaped apart. Now we believe that 

 a river is not there because of the \'al- 

 ley, but the valley is there because of 

 the river, which gradually cut and carv- 

 ed its way through the solid land, and 

 has thus led to the formation of the 

 valley. 



Let us grant, therefore, that running 

 water has made tllB canons of Lozere; 



but did the water begin its work below, 

 or did it cut its way down from the 

 surface.' That is the question at issue. 

 Limestone formations are always full 

 of fissures, caves, and caverns, which 

 have evidently been occupied and en- 

 larged by subterranean streams. If 

 the roof of such a cavern fell in, would 

 it not present the features of a canon.' 

 It is quite possible that it would, in 

 many respects; but it is exceedingly 

 unlikely that the roof of a deep-seated 

 cavern should fall in completely for 

 an}' great distance. 



(TO BE CONTINUED.; 



Visions of tae Past. 



(CONXLUSION.) 



One hundred and fifty \ears have 

 passed. We feel like strangers as we 

 wander over the conntry — so changed. 

 We see no guiding landmarks to aid 

 us in finding the places once so famil- 

 iar to our footsteps. 



The hills, valley and streams are 

 unfamiliar. The forest has fallen — 

 the keen axe has laid it low, and fire 

 and time — long ago — destroyed every 

 vestige of the stumps. Peaceful fields 

 and pastures extend as far as the eye 

 can reach, only broken here and there 

 by narrow strips of wood and brush 

 along, and in some inaccessible rough 

 or rocky gulch. 



No longer we hear the music of 

 splashing brooks, their beds are dry; 

 and even the once deep-flowing river 

 is shrunken to the center of its chan- 

 nel. 



The inventions of the fertile brain 

 of the white man — the steam cars — 

 are continually moving up and down 

 each side of the winding river with 

 lightning speed, carrying safely each 



