Prof. T. G. Bonney—Alpine Passes and Peaks. 547 
Antrona. On the first spur, full ten miles to the north of the 
Matterhorn as the crow flies, we find the Weisshorn, actually the 
higher by about 100 feet; the other peaks to the south being well 
above 13,000 feet, and the lowest gaps between them not much 
under 12,000 feet. Opposite to the Weisshorn rises the mass of the 
Mischabel-hérner, the highest peak of which almost reaches 15,000 
feet, and there is no point in the range south of it till we have passed 
the Strahlhorn, which falls much below 12,000 feet, while its peaks 
are all over 13,000 feet above the sea. Lastly, in the rather less 
elevated range east of the Saaser Visp, we find peaks somewhat 
over 13,000 feet in height separated by passes which are not much 
below 12,000 feet. As may be inferred from what I have already 
stated, the principal gaps in the rocky rampart enclosing the head 
of the Gorner Visp correspond with the direction of its main axis, 
and of the tributary glens now occupied by the glaciers, Zmutt, 
Gorner, and Findelen. These gaps I attribute to the destruction of 
the original party walls by the recession of the heads of the Italian 
valleys. In order to comprehend the process by which the above- 
described structure has been produced we must dissolve away snow 
and glacier, and must replace the myriad millions of cubic yards of 
rock which have been removed by the action of water in all its forms. 
We will, however, for simplicity, suppose any covering of Secondary 
rocks already stripped off. We may then picture to ourselves a 
broad arch of crystalline rock, slowly rising, perhaps not without 
pauses, until its flattened crown is full three miles above the sea. 
Its chord extends from the present valley of the Rhone on the one 
side perhaps to the Italian plain on the other. Into this mass the 
streams which start from its higher surface cut deeply, working 
their way backwards, and excavating the valley, so that every peak 
is a “locus of least denudation,” standing like one of those prisms 
of earth which excavators leave to indicate the amount which they 
have removed. 
It may be asked why, if the above explanation be correct, do we 
not find spurs on the southern side of the Pennines comparable with 
those on the northern. I reply because they have suffered more 
from and have been partly destroyed by the more rapid recession of 
the valleys on this side. As their tributary glens enlarge, as the 
great corries at their heads are extended, laterally as well as back- 
wards, so the intervening masses suffer from corrosion, and at last 
even the peaks, which have for long been spared, must obey the 
general law, “ Dust thou art and unto dust thou shalt return.” 
But on this subject passing time forbids me to dwell longer. I 
will only say that I believe the principles which I have indicated to 
be of general application in all mountain regions. There are, however, 
two topics indirectly connected with questions of Alpine sculpture 
which call for a brief notice. These are (a) what effects have snow 
and ice as erosive agents compared with running water, and (b) to 
what extent have the Alps, in the past time, been occupied by snow- 
fields and glaciers? I have already said that I believe that, 
compared with torrents, glaciers are erosive agents of secondary 
