583 
ON LAKE BASINS. 
BY PKOFESSOE D. T. ANSTED, M.A, F.R.S. 
K>« 
T here is no subject of general interest in geology and 
physical geography that has more attracted the attention 
of the scientific world_, and been the cause of more lively discus- 
sion of late years, than that of the origin of Lake Basins. 
Some geologists, deeply impressed with the grandeur of ice- 
action, and the unmistakeable marks of force exhibited by it, 
have assumed that all the deepest gorges and hollows now 
occupied by water have been scooped out by glaciers. Others, 
equally affected by the evidence of the erosive power of water 
in its fluid state, have thought that, either by fioods or by the 
effects of great rivers, these hollow spaces have been first 
made and then left full. Geologists having strong faith in 
crashes and violent upheavals and depressions, are quite 
willing to accept as sufl&cient causes for all lake basins the 
faults, axes, and other disruptions and disturbances of strata 
effected rapidly and convulsively, as they believe, during the 
elevations of mountains and the formation of continents. 
Thus there is ample ground for discussion, and it must be 
confessed that in some respects the battle is something like 
that between the Neptunists and Plutonists in the earlier days 
of geology, when neither party had much opportunity or 
desire of appealing to nature to decide, but was none the 
worse combatant because he was more inclined to appeal to 
arguments than to discover facts. 
Under these circumstances, perhaps, a short account of 
some of the principal lake basins of the world, with a view 
to show the varieties that exist, the circumstances under which 
they exist, their peculiarities of form and position, their mag- 
nitude and depth, and the form of their bottoms, when known, 
will form an interesting and useful introduction to a short 
notice of recent theories on the subject, and the conflicting 
views of some of our best modern geologists as to their 
origin. 
The great ocean itself is but a vast lake basin, the whole of 
whose bed lies below a certain level, or, in other words, at a 
certain mean distance from the eartlFs centre. This condition 
