368 Notices of Memoirs — Glacial Progress. 



absence of an imderclay beneath the coal-seams, such as is generally 

 found below European and American coal-beds, and in which the 

 roots of StiymaricB and other plants are to be found. According 

 to the observations of Mr. Draper, the coal now being worked at 

 Vereeniging, by Messrs. Lewis and Marks, has a soft layer of 

 whitish clay underlying the coal ; but, as if to prove the futility 

 of applying general theory to each particular case in South African 

 geology, this underlying clay is apparently a decomposed sheet of 

 dolerite, which had intruded below the coal, and, in many parts, 

 penetrated into it, changing the coal into coke in the neighbourhood 

 of the intrusion, and giving it more the nature of anthracite through- 

 out its area. The endeavour to establish a geological horizon for 

 the coal-beds in South Africa has not hitherto led to much practical 

 result. We have Professor Seeley's recent opinion that coal must 

 not be looked for below the strata containing the remarkable 

 characteristic fossil reptilia. Further, we have Mr. Stow's original 

 deduction that coal would be found from 70 to 150 feet below the 

 silicified tree-stems which he traced over a large area in the north 

 of the Cape Colony, and over a still greater extent in the Free State, 



and which he termed the forest zone Mr. Stow's prediction 



that the coal would be found to crop out on the north-west of his 

 forest zone has since been abundantly verified at the Vaal Eiver. 

 Nothing like a true Carboniferous system has yet been made out 

 for South Africa ; and though ferns, such as Glossopterts, have 

 been found, this and some others are looked upon as survivals of 

 Carboniferous plants into Jurassic times." 



After some observations on the Coal-beds in the Stormberg and 

 at Lake Nyassa, of the same Karoo series, Dr. Exton concluded with 

 an exhortation to geologists to lose no opportunity in elucidating the 

 many interesting and, indeed, most important problems lying at 

 their feet in the subterranean strata, and before their eyes in the 

 many and varied escarpments of hills and mountains around them. 



IL — Glacial Progress. By Captain Marshall Hall, F.C.S., F.Gr.S. 

 [From the "Alpine Journal," No. 128, May, 1895.] 



SINCE the appointment of the Sub-Committee upon Glacier 

 Observations ^ sufficient time has not yet elapsed for many 

 exact data to have come to hand, with one very brilliant exception — ■ 

 that of New Zealand. 



Amongst the explorers of the Southern Alps are men not only 

 mountaineers, but who are also greatly interested in these problems, 

 shrewd observers and efficient officers of the New Zealand Survey. 

 We have the novelty of new excursions, combined with the deter- 

 mination of a series of positions upon which to found future 

 measurements, and all this in mountain ranges till recently scarcely 

 known. The writer will give a summary of this work (with great 

 conciseness, the result of instructions he has received). In the 



1 Geol. Mag., 1895, March Number, p. 144. 



