480 
secretary's report. 
lateral moraines, but dwindling in numbers as the limestone hill 
was ascended. A careful search was made over the upper scars 
of Norber, with the view of ascertaining the highest point to 
which one of the Silurian boulders had been lifted by the ice. 
One was found near the flagstaff, the height being estimated, 
by aneroid observations, as 1,260 feet above O.D. Many others 
were found scattered about at a slightly lower level. On the 
lower scars man}^ of these boulders are beautifully perched on 
limestone pedestals, about 18 inches in height. These boulders 
have protected the limestone on which they rest from the eroding 
action of the subaerial denuding agencies, and the height of the 
pedestal is a measure of the time since the boulder was left on 
the bare scar by the ice. Under some of these perched 
boulders the limestone was found to be beautifully grooved and 
striated, the groovings passing across the joints, and affecting 
the fossils on the surface and pointing directly up the dale. 
One of the heaviest boulders had fallen over and lay on a crushed 
mass of limestone, showing that its weight had become too much 
for the gradually weakened pedestal to bear, and it had given 
way. Several of the most interesting blocks were photographed. 
The party then descended into Crummack Dale and examined 
the outcrop of the Austwick Grits, from which the Xorber 
boulders had been derived. These grits form a ridge striking 
across Crummack Dale, which is part of the Silurian sea-plain 
on which the Mountain Limestone beds were laid down. Where 
hard grits existed this sea-plain was left in prominent ridges, 
whereas, where beds of shale or softer sandstones existed, inter- 
mediate hollows were left, and thus the base of the Mountain 
Limestone assumes an undulating form. The boulders increase 
rapidly in numbers as the outcrop of the Austwick Grits is 
approached. They were evidently masses torn off the grit beds 
on the dale side by the advancing ice, and are the result of its 
final efforts. Careful observations were taken of the highest point 
reached by the "live" rock, and this proved to be 1,210 feet 
above O.D. This showed that there had been a minimum uplift 
in the case of the highest boulders found, of 50 feet above the 
