81 
approximate, but I think they are sufficient to show that 
many geologists have shown a tendency to exaggerate the 
time which has elapsed since the close of the glacial period. 
12. Fresh Appearance of Ice-marks and Moraines.—W hat- 
ever difference of opinion there may be concerning the time 
indicated by the height of the limestone pedestals of boulders, 
all must admit that the recency of the close of the glacial period 
is forcibly suggested by the extent to which ice-marks on 
rocks have been preserved in positions where they could 
never have been protected by drift from atmospheric action, 
and where their freshness is consequently owing to the com- 
paratively short time they have been in existence. In many 
of the upper valleys of Cumberland, glacial moraines present 
so fresh an appearance, that an unsophisticated person newly 
introduced to the district might readily suppose that they had 
not been more than two or three years in existence. On some 
of these moraines stones must have been so delicately equi- 
poised on each other by the retreating glacier, that a touch 
of one’s finger would now be sufficient to make the fabric 
topple down ! 
13. Perennial Snow or Ice on High Plateaux during Neolithic 
Times.—Professor Geikie, as already stated, is of opinion that 
the second great glacial period was divided into two by a mild 
interval. But though this may have been the case in Scotland, 
or farther north, it may not have been so (at least to the same 
extent) in England and Wales; and I think we are therefore at 
liberty to believe that on the high plateawe in the north of 
Wales and England, which form the main subject of this 
paper, ice, or ice alternating with snow, may have been 
perennial, though it may have been different in the lowlands 
and farther south. If so, ice or snow on the Hglwyseg and 
Norber plateaux, which rise to between 1,000 and 1,300 feet 
above the sea-level, may have lingered until about 6,000 years 
ago, so as to protect the supports of boulders from the action 
of rain. 
14. Close of the Glacial Period in North America.—It is 
well known that many American geologists (including several 
who have been honoured by the Council of the Geological 
Society of London) are convinced that the glacial period in 
the Niagara and Michigan district ter ‘minated so late as about 
6,000 years ago. From recent reports it would appear that the 
Niagara Falls have lately been receding at about the rate of 
ten feet in twenty-four years, or about two and a half feet in a 
year ; and this accords with the results of observations made by 
the late Mr. Belt and Dr. James Hall, who found that the Falls 
had receded in solid rock about three miles since the Niagara 
