394 REPORT—1905. 
glaciated by the presence of striations ought not to present other features 
significantly unlike non-glaciated mountains; if the former supposition is correct, 
then glaciated mountains should present features significantly unlike those of non- 
glaciated mountains, and these features should be in form and distribution 
appropriate to glacial action. An appeal to the facts leaves no doubt in the minds 
of many observers that significant differences between the two classes of mountains 
certainly exist, and that they are of a kind that glaciers would produce if they 
could. Over-deepened main valleys with over-steepened walls, hanging lateral 
valleys, valley-head cirques, and exceptionally sharp ridges and peaks characterise 
strongly glaciated mountains, and are absent from non-glaciated mountains. These 
peculiar features, systematically associated, cannot be explained by normal non- 
glacial erosive agencies ; nor can it be supposed that any special or exceptional 
agency can have produced them, for this supposition would require that the special 
agency selected in pre-glacial times all those mountains that were afterwards to be 
glaciated, and ina most systematic and prophetic manner worked upon them just 
as glaciers would work it they could, and then withdrew into obscure inactivity, 
where they remain undiscovered to this day. Such a supposition is absurd The 
evidence now in hand from the Alps, Norway, Alaska, the Rocky Mountains, the 
Tian Shan, New Zealand, and elsewhere is so abundant and consistent that it has 
in recent years led many observers to accept the belief that glaciers can erode, and 
that they have been effective agencies in the sculpture of certain mountain ranges, 
even though the processes of glacial erosion are not yet fully understood. 
FRIDAY, AUGUST 18. 
The following Papers and Report were read :— 
1. Ona Subterranean Tide in the Karroo. 
By Professor AnprEw Youne, IA., B.Sc. 
This paper was of the nature of a first notice regarding an investigation which 
is in progress as to the nature of certain periodical variations in the rate of discharge 
of an artesian well in the Karroo, on a farm called ‘Tarka Bridge.’ The site of 
the well is over 2,700 feet above sea-level, and fully 100 miles from the coast. 
The bore-hole is only 65 feet deep, but there is a large and regularly fluctuating 
artesian supply of water at a constant temperature of about 80° F. accompanied 
by a great quantity of inflammable gas. f 
A self-recording apparatus placed in a tank over the bore-hole has given 
continuous records for some few weeks. The record is a curve showing a series 
of waves of remarkable regularity, the average wave-length being within a few 
minutes of 12} hours. A comparison of wave amplitudes shows a marked 
variation of the height of the waves, corresponding in time to the phases of the 
moon and analogous to the phenomena of marine spring and neap tides. 
It was suggested that the water rises through a fissure-system from a depth of 
several thousand feet mainly under the influence of the pressure of natural gas, 
and that the tidal fluctuation is a minor lunar effect superimposed on the effect of 
fairly constant gas pressure. : 
A comparison of this tidal record with the barograph records obtained simul- 
taneously, shows that variations of barometric pressure play a very insignificant 
part in the production of the variations of water-pressure in the bore-hole. 
2. The Stormberg Formation in the Cape Colony. 
By Auex. L. pu Torr, B.A. 
The Stormberg Formation is the uppermost division of the Karroo System in 
South Africa, and builds up the whole of Basutoland and the adjoining portions of 
the Cape Colony, the Orange River Colony, and Natal. In the Cape Colony the 
