1864. | The President's Address. 739 
were then divided ;” and when the sea flowed over Moel Tryfaen, a 
hill near the Menai Straits, where fossil marine shells have been found 
at a height of 1,860 feet above the present sea-level. 
Passing then to the question of the changes in temperature which 
must have taken place in England, in common with the whole of 
central Europe (and speaking chiefly in relation to the Glacial period), 
he attributes these changes in part to a general alteration in the height 
of the seas, continents, and mountain ranges; and shows that at one 
time the Sahara, or great Desert of Africa, must have been under 
water; the high lands of Barbary, &c., separated from the rest of 
Africa by a sea; and that there has probably been a connection be- 
tween Barbary and Southern Europe. The gradual melting away 
of the Swiss glaciers, Sir Charles attributes to some extent to 
the Sirocco, or, as the peasants call it, “the Fohn,” which hot wind 
crosses over from Africa; and showing that a cessation of this warm 
blast, for a brief period only, causes the ice to accumulate perceptibly 
even in our day, he asks, ““ What mighty effects we may not imagine 
the submergence of the Sahara to have produced in adding to the size 
of Alpine glaciers?” or as Escher* argues, “If the Sahara was a sea 
in post-tertiary times, we may understand why the Alpine glaciers 
formerly attained such gigantic dimensions, and why they have left 
moraines of such magnitude on the plains of Northern Italy and the 
lower country of Switzerland.” 
“The more,” says Sir Charles, “we study and comprehend the 
geographical changes of the Glacial period, and the migrations of 
animals and plants to which it gave rise, the higher our conceptions 
are raised of the duration of that subdivision of time, which, though 
vast when measured by the succession of events comprised in it, was 
brief if estimated by the ordinary rules of geological classification.” 
It is unnecessary to follow the President through the review which 
followed, of the story of man’s antiquity as it is at present related by 
Archzologists and Paleontologists; suffice it to say that he traced 
him through the “ Age of Bronze” to the Stone period, when “ flint 
implements” were almost his only weapons, and when his bones lay 
side by side with the extinct quadrupeds of Europe—the ‘ Elephant, 
Rhinoceros, Bear, Tiger, and Hyena.” 
After referring humorously to the reluctance with which some 
students of Geology bring themselves to consider the long ages that 
modern science is disposed to attribute to the Glacial and Post-glacial 
periods, Sir Charles concludes his Address with a few observations 
upon two questions at present agitating the scientific world: “ First, 
as to whether there has been a continuous succession of events in the’ 
organic and inorganic worlds, uninterrupted by violent and general 
catastrophes ; and secondly, whether clear evidence can be obtained 
of a period antecedent to the creation of organic beings on earth.” 
In regard to the first point, Sir Charles here speaks with great 
caution, but we think it may be gathered from his remarks that he 
considers the “convulsionist” theory to be dying out and giving place 
* Escher yon der Linth, 
