3 6o 
Past Changes in the Universe. [July, 
brow of the valley. Prof. Prestwich has also observed 
transported rocks on the top of Well Hill, in Kent, at 
600 feet above the sea. Along with large rolled flints were 
found a few fragments of chert and ragstone, which he refers 
to the Lower Greensand of the Sevenoaks range, some six 
miles further south, separated by the broad and deep valley 
of Holmsdale.* Mr. Whitaker has also seen lumps of hand- 
chalk, in Kent, at a high level, on Crocken Hill, eastward 
of St. Mary’s Cray ;t and Prof. Morris has informed me 
that there are patches of the loess, with its characteristic 
shells, preserved in fissures of the chalk at Bensted’s Quarry, 
near Maidstone. 
We have an obvious explanation of the nearly total ab- 
sence of northern drift south of the Thames in the theory 
that the Upper Diluvium was distributed by ice, floating 
over a great lake draining to the Mediterranean by way of 
the Black Sea ; for the currents from the South of England 
would flow to the north of east, to get round the Hartz 
Mountains, and might be deflected still more to the north 
by those from the valley of the Rhine, and from the area of 
the English Channel. 
III. ON THE POSSIBILITY OF EXPLAINING 
PAST CHANGES IN THE UNIVERSE 
BY CAUSES AT PRESENT IN OPERATION. 
By S. Tolver Preston. 
& NY attempt to explain the phenomena of Nature by 
the recognised working of physical causation has 
been invariably welcomed. Thus the explanation 
of geological changes through the influence of time, by the 
recognised working of natural causes, is now generally 
accepted with satisfaction, and the idea of cataclysms or 
catastrophes has been abandoned. Might not the same 
thing apply to cosmical changes (or to changes in the Uni- 
verse), or would not an attempt to explain them by the 
* Geological Magazine, O&ober, 1874. 
f Geology of London, p. 52. 
