ILLUSTRATION OF ICE-FLOE ACTION NEAR UPSALA. 
547 
each successive reduction of that body. At length, when reduced to the minimum 
size at which it could be held together, it would, in dissolving, necessarily shed its 
load upon the sloping talus of the os, the blocks being assisted by the same cur- 
rent in their southward progress down the slope of the submarine hill. This case 
appears to us to be so illustrative and confirmatory of our views, that w r e annex 
two small diagrams giving a plan of the ground and a profile view of the same. 
a. Ancient submarine hill composed of sea sand and clay, with Tellina Baltica , and now forming the land called Tun-os. 
b. Iceberg in its largest state when arrested by the submarine hill. 
c cccc. Terraces of gravel formed successively as the iceberg was forced southwards. 
d. Iceberg in its last state, when diminished and advanced to the south, exposing blocks and gravel within it. 
e. Talus covered by blocks derived from the melted iceberg. direction of the current. 
In this enlarged plan, the converging terraces (cc) of the section are represented to the left, the line of 
blocks (/) to the right. 
These phsenomena at Old Upsala seem to us fully to indicate the difference be- 
tween the sub-aqueous and highly-rolled, tumultuous drift, which like the “ till” 
of Scotland, resulted from some of the earlier oscillations in these latitudes, and 
the operation of the currents upon icebergs which were stranded and dissolved ; 
for had the same power of water been there in play, as that which formed the 
Bronkeberg Os near Stockholm and many others like it in Sweden, the blocks in 
question, although they, for the most part, lie to the lee, or sheltered side of the 
hills, would have been rounded and polished, whereas nearly all of them (and the 
