NATURE 
[| Aug. 18, 1870 
THE ICE AGE IN SWITZERLAND* 
F one might venture to use the word “romantic” in 
reference to the history of any past geological period, 
it would certainly with most fitness be applied to that 
time, so recent and yet so remote, which we know as the 
Ice Age. The story of the old glaciers, like that of the 
living ones, has a perennial interest. We listen to it over 
and over again without wearying, much as we used to do 
with some of the standard tales of childhood. For even 
though we are now familiar with the evidence which 
proves that, at no very distant date, the northern parts of 
Europe and America, including nearly, if not the whole, 
of our own country, lay buried under a vast sheet of ice, 
the fact is so strange that every fresh presentation of it 
comes even yet before us with not a little of the charm 
of novelty. Hence every description of new facts which 
tends to elucidate the history of the Ice age in arly one 
locality possesses a more than local interest and import- 
ance. More particularly is this the case when the 
description relates to Switzerland. The Swiss glaciers of 
to-day have become in a manner the common property 
and fighting-ground of the geologists of all countries ; and 
all fresh observations which bear on the ancient extension 
of these glaciers are welcomed as additions to the common 
fund of geological knowledge. 
But there is a peculiar interest attaching to the publi- 
cation the title of which is given below. It is not only 
a most meritorious contribution to geological literature, 
showing in great detail the history of glacial phenomena 
in one of the Swiss cantons, but it may be taken by all 
local scientific societies as a model of what enthusiasm 
and industry, well directed, may accomplish. Its origin 
and growth may be briefly stated. In December of 1867 
the Natural History Society of Aargau determined that 
the year 1869, being the fiftieth of its existence, should 
be marked by some fitting celebration. It was suggested 
that, besides the usual festivities, it would be well if the 
society would engage in some piece of scientific work, so as 
to present the result at the anniversary ; and it was finally 
resolved to make an extended and detailed survey of the 
erratic formations of the canton. General attention had 
been roused to this subject by the Swiss Naturalists’ 
Society in 1867. That body had issued a circular 
inviting all authorities and private individuals throughout 
Switzerland to preserve the erratic blocks which were 
rapidly disappearing before hammer and gunpowder, 
MM. Favre and Soret, of Geneva, had likewise pointed 
out the desirability of having an accurate map made of 
the distribution of erratics in the country. Accordingly 
communications were entered into with the federal and 
cantonal authorities, who cheerfully lent their assistance. 
A circular was sent out inviting all and sundry to 
give their aid towards the ascertaining and mapping of 
the erratic blocks in the canton Aargau. In that docu- 
ment were likewise given directions as to the nature of the 
-observations to be made. Each of the fellow-workers 
was requested to note in a schedule the erratic blocks (or 
foundlings, as they are happily termed in German) of his 
neighbourhood, with an exact record of the locality of 
each block, its local name, height above the sea, 
_* Ueber die erratischen Bildungen im Aargau, &c. Tin Beitrag zur 
Kenntniss der Eiszeit, yon F, Mihlberg. (Aarau; H. R. Sauerlander.) 
proprietor, the nature of the rock of which it con- 
sists, the legends, if any, connected with it, such human 
marks as might have been carved on it, and any 
other remarks that might seem important. To conduct 
the whole inquiry a reporter or secretary was appointed. 
His duties were to receive and reduce into connection and 
order the reports of the various volunteer surveyors ; and 
that he might the better perform this task, he was autho- 
rised at the public cost to visit the more remarkable locali- 
ties, to mark those blocks which he considered it desirable 
to preserve in the interests of science, and to preserve two 
type specimens of all the more important blocks, the one 
specimen to be deposited in the Aargau Museum, the 
other to be sent to M. Favre at Geneva. The blocks lying 
on State property were to be considered thenceforth invio- 
lable, and for the conservation of those resting on other 
lands the secretary was authorised to treat with the pro- 
prietors with a view to the acquisition of the blocks by the 
State, By thus taking advantage of the general move- 
ment the Aargau Society not only aided in a work of 
national interest, but gained an opportunity of celebrating 
in a singularly excellent way its own anniversary. 
The result of the undertaking is now before us in the 
form of an octavo volume of upwards of 200 pages, with 
a map showing the distribution of erratics and the exten- 
sion of the old glaciers over the canton. A more admi- 
rable piece of work has not been done in glacial geology 
for some time. The society deserves the warmest thanks, 
and more especially the reporter, Herr Miihlberg, who 
first suggested the task, and on whom the main share of 
the labour has fallen. The course of each of the ancient 
glaciers is traced by the lines of “ foundlings” which it has 
left in its path. The evidence furnished by the Canton 
Aargau as to the retreat of the ice is carefully collected. 
The limits of the second glaciers are mapped out, and 
abundant details are furnished as to their moraines. It 
has long been familiar knowledge that the great glacier of 
the .Rhone, after abutting against the Jura mountains, 
pushed an immense body of ice eastwards over the low- 
lands of Switzerland as far as the district round Soleure, 
But we now learn that rocky dééris borne along by the 
huge glacier has been traced even up to the Rhine at the 
confluence of the Aar. Swelled by the numerous streams 
of ice which came down from the Bernese Oberland, the 
united glacier of the Rhine and Rhone must have poured 
an enormous mass of ice down the Rhine valley, between 
the Black Forest and the Jura. 
The sequence of events in Switzerland since the close 
of the Tertiary period is thus epitomised by Herr 
Mihlberg :— 
1. Close of the Tertiary period, elevation of the Alps, &c- 
2. Erosion of the valleys in the area of the molasse. 
3. Renewed elevation of the Jura, formation of the 
barriers at Aarburg, Wildegg, &c., and consequent lake- 
basins, 
4. First and greatest extension of the glaciers even to 
the highest crests of the Jura and over the whole canton. 
Northern limit of theice unknown ; accumulation of bottom 
moraines (Grundmorane, moraines profondes) upon the 
“ Stoss-seite” of the hills. 
5. Retreat of the glaciers, with deposit of earthy rubbish, 
angular blocks, scratched stones, sand and gravel ; filling 
up of the lakes behind the above-named barriers (save 
