iN Git MOM al 
THURSDAY, JUNE 29, 1871 


RAMBLES ROUND LONDON 
Saturday Afternoon Rambles Round London, Rural and 
Geological Sketches, By Henry Walker. 
Hodder and Stoughton. 1871.) 
HE title of this book is suggestive of one of "the 
(London : | 
movements of modern times, the Saturday Half- | 
holiday, a movement in the right direction, if the reci- 
pients of the boon fully appreciate and understand how 
to use it beneficially. This may be done in various ways, 
either in the study of the subjects contained in the 
different museums in the Metropolis devoted to Art, 
Manufactures, or Natural Science ; or in excursions in 
the vicinity, either for obtaining health or becoming ac- 
quainted with the various natural objects met with in the 
rambles, thus adding to the stock of intellectual and 
physical enjoyment, enlarging knowledge, and, perhaps, 
adding some new fact to the already rich stores of local 
observation. The institution of Field Clubs and Natural- 
ists’ Societies is not altogether new in principle, but their 
steady increase is a marked feature of late years ; and 
while they have largely contributed to stimulate more 
systematic researches, they have at the same time exer- 
cised a social influence in bringing together persons 
whose tastes and pursuits have generally for their common 
object the investigation of the varied manifestations of 
creative intelligence. To those whose love of natural 
history leads them into the field, this small volume will 
be found a useful companion and guide, as it gives in a 
very able and pleasant manner much useful information 
respecting the more favoured spots easily accessible by 
the naturalist around London. 
We can believe that these “Saturday Half-Holiday 
Rambles” have been the means of emancipating many 
young men from the gas-light hours on the Saturday to a 
good long afternoon of daylight. Many of them who 
have rural tastes, and even tastes for natural history, have 
never heard of the Quekett, the Geologists’ Association, 
the South London Microscopical, and other London 
societies, part of whose programme consists of natural 
history rambles on the Saturday afternoon. So huge a 
place is London that there is danger of the amateur natu- 
ralist foregoing much that he might profit by, for want of 
such knowledge. The more we know of London life, the 
more do we see that this is the kind of work for young 
men closely engaged in the exhausting pursuits of a great 
city. Natural history pursuits are just the recreation they 
need ; and the movement inaugurated by the energetic 
Secretary of the Saturday Half-holiday Committee of the 
Early Closing Association appears to fill up a gap in the 
previously existing modes for employing their time. 
The Saturday Afternoon Rambles comprise London park 
and forest trees, Battersea Park, with its subalpine and 
tropical floras, Kew Gardens, visits to Burnham and 
Knockholt Beeches, Hampstead Heath and Hornsey, and 
autumn tours round Godalming. Interesting, however, as 
is the present landscape scenery of these districts, the 
author carries us back to the more ancient geography 
of the London area: the old sea-bed in Middlesex, and 
VOL, IV. 

157 

the subsequent changes it has undergone, and by which 
the present physical features have been produced. 
Among the many interesting geological features to be 
noticed in the neighbourhood of London, the Thames 
valley is one, and is fully described in the work before us. 
Few of us are aware, except those acquainted with Mr. 
Prestwich’s work, “ The Ground beneath Us,” that the 
familiar Thames of to-day has a pre-historic history dis- 
tinct from its association with man and his fortunes, from 
which it is too commonly supposed to derive its sole in- 
terest and charm Still, the Thames, if we trace it from 
its source to the sea is replete with considerable interest, 
especially when we take into consideration the origin and 
character of the strata over which it flows in its onward 
course. These rocks reveal to us successive changes in 
the physical features and distribution of land and water 
during long past periods in the history of the globe ; they 
tell us of successive oceans, or perhaps to some extent of 
a continuous ocean, more or less tropical in character, 
abounding in various forms of life adapted to the then 
existing conditions, which forms were successively re- 
placed either by evolution or by new creations, coincident 
with the different inorganic changes which that area has 
undergone. 
Without entering into a description of these changes 
(which we feel will be fully illustrated in the forth- 
coming work by Prof. Phillips), we will attempt to 
trace from the book before us the origin and condition 
under which the deposits in the Thames valley were accu- 
mulated, such as those which may be observed from the 
neighbourhood of Kew to Erith, and beyond it. The 
present stream, the parent of commerce and of civilised 
life, with its valley so rich in interesting landscapes, is but 
a diminished representative of a pre-historic larger river, 
by the agency of which, to a considerable extent, the present 
valley was formed. Even in the vicinity of London we 
have traces of older sea beds, such as the chalk, the 
London clay with its subordinate estuarine beds of the 
Woolwich series, and its overlying marine strata of 
middle Eocene age represented by the Bagshot sands, 
capping here and there the summits of the adjacent hills, 
and these again overlain by deposits of much later age, 
and indicating considerable change in the climatal condi- 
tions of the period, namely, the beds of glacial age which 
abut upon the northern heights of the valley, as at High- 
gate and elsewhere. That the present physical features 
of the Thames valley are of remote antiquity there can 
be little doubt, and many have been the opinions sug- 
gested as to its origin and age. Some have considered it 
partly of preglacial or glacial age, others as due to the 
torrential action of vast bodies of water produced by the 
summer thaws when the winters of England were of an 
arctic severity, or that the river itself was the agent by 
which the valley was formed. Suffice it, however, to 
say that from the corresponding nature of the strata on 
each side, which shows they were once continuous, 
for instance between Highgate and Norwood, it is 
evident, as suggested by Mr. Prestwich, that the valley 
of the Thames acquired its present dimensions in a 
period of greater atmospheric waste than the present, and 
of river erosion of greater intensity. Whether or not its 
features were partially moulded previous to the glacial 
period, it is probable that during the emergence of the land 
K 
