ANNIVERSARY ADDRESS.. 21. 
measures differed 4 inches. Some were taken to the edge of the 
1871 gravel as nearly as it could be determined, and others to the 
high-water-mark on the old dead trees. During the day the regis- 
ter shows a variation of level in the water of 2 inches, which, as it 
was rising and falling, was probably eliminated in the mean. If, 
therefore, we add together the differences between the present water 
level and that of 1871, between that and the top of the gravel ridge, 
we find it is 34} feet, and at one time the lake must have been as 
high or nearly as high as that in order to pile up the gravel. At 
first it is difficult to see any reason for the formation of the gravel 
deposit where it is; but looking at the 1871 level, one sees the 
nucleus of another in a thin line of gravel about 1 foot thick. Such 
a deposit on flat ground would grow, if the level of the water was 
at all constant, and gradually a ridge would be formed. The di- 
rection of these ridges at right angles to N.E. and S.E. winds 
points to a probable past when the winds were alternately from 
these directions during long periods; and as the gravel is made at 
the western edge of the lake and not at the ends, it musthave been 
transported along the margin and thence out on to the flat country 
by the action of the waves. 
In the absence of levels it is impossible to say what was the 
extreme size of the lake in its wet period, but, I should think, at 
least 40 miles long and 10 or 12 wide. The steep hills which 
bound the lake on the west side are deeply furrowed by water, 
and afford striking evidence of a time when rain must have fallen 
in vastly greater abundance than it does at the present day. Each 
of these gullies when examined is found to have a more or less 
extensive delta, which has spread out laterally and into the lake, 
forming there a projecting point opposite the gully. These are 
now covered with trees, and add very much to the beauty of the 
lake by their picturesque effect. In many cases, especially at 
the south end of the lake—that is, near Douglas House—these 
deltas are cut through by the watercourse which serves to carry 
off the rains of the present day ; and these reveal distinctly the 
character of the deposit through which they run, showing that it 
