1892 - 93 .] 
Chairman's Opening Address. 
5 
portion of the Garlton Hills ; while Messrs J. Horne and J. 'J. H. 
Teale have shown that a group of rocks, which from being extensively 
developed near Loch Borolan, they propose to call Borolanites, 
consist of a crystalline granular aggregate of orthoclase and melanite, 
and belong to the elaeolite-syenite family. 
Last session Professor James Geikie communicated to us one of 
those great geological papers which have done so much credit to our 
Society, in which the author has propounded views, in many respects 
striking and original, regarding the evidences of a succession of ice 
ages. In this paper on the glacial succession in Europe, Professor 
Geikie gives a general review of the evidence which has accumulated 
during late years. He is of opinion that the climatic changes of 
the glacial period were more numerous and complete than is gener- 
ally supposed. According to him, five cold or glacial epochs have 
alternated with four genial or interglacial epochs. The first cold 
epoch and succeeding genial period supervened in Pliocene times. 
Thereafter followed the second glacial epoch, during which the cold 
conditions were most intense. This was indeed the climax of the 
glacial period, when a great ice-sheet flowed south into Saxony — the 
British and Scandinavian mer de glace being confluent in the North 
Sea basin. Again the climate changed, and genial conditions, 
comparable to those of the present, obtained in Northern and North- 
Western Europe. This second interglacial stage was followed as 
before by a glacial relapse, when the British and Scandinavian ice sheets 
again coalesced, hut the northern mer de glace did not flow further 
south on the continent than the valley of the Elbe. Once more 
glacial conditions disappeared, and were succeeded by the temperate 
climate of a third interglacial epoch. Erelong, however, the 
temperature again fell, and the fourth genial epoch ensued. Great 
snow-fields and glaciers then came into existence in the mountainous 
districts of the British Islands, while Norway, Sweden, and Finland 
were largely ice-clad — a mighty glacier occupying the basin of the 
Baltic, and invading the low grounds of North Germany, Schleswig, 
Holstein, and Denmark. The British and Scandinavian ice, how- 
ever, did not again become confluent, — the mer de glace of Norway 
calved its icebergs at the mouths of the great fiords all along the 
west coast of that country. Eventually these glacial conditions 
passed away, and a temperate climate followed, during the pre- 
