REVIEWS. 
239 
without wishing to say there is no such thing as an elevation of the land, 
we would certainly ask geologists to bear in mind the possibility of 
there being variations in the level of the sea. The slow change in the 
direction of the polar axis, and the possibility of alterations of the axis 
itself, suggest at least two ca'.:ses Avhich might effect very considerable 
differences in the bulging of the sphere of waters round our globe ; and 
some such natural and recurring changes as would be tlnis brought about, 
seem more likely tban so many jumpings up and down of that solid land, 
which at any rate appears to be very steady just now. Then, -what ]\Jr. 
Geikie, who is referred to on the point, considers as evidence of upheaval 
within the historical period, Mr. Carruthers looks upon in a very different 
The sixth and concluding lecture has for its subject the special effects of 
the Physical Geolog}' of the country on population and industry, a subject 
of general interest, and althou^^h briefly yet clearly treated, the concluding 
paragraphs deserve quotation. 
" It is interesting to go back a little and inquire what may have been 
the condition of our country when man first set foot upon its surface. V^o 
know that these islands of ours have been frequently united to the Conti- 
nent, and as frequently disunited, partly by elevations and depressions of 
the land, and to a great extent also by denudations. "When the earliest 
human population reached their plains, they were probably united to the 
Continent. Such is the deliberate opinion of some of our best geologists. 
They do not assert it as a positive fact, but they consider it probable that 
these old prehistoric men inhabited our country along with the great hairy 
mammoth, the rhinoceros, the cave-bear, the lion, and the hippopotamus ; 
that they travelled westwards from the continent of Europe, along w ith 
these extinct mammalia, over that continuation of the land wliich originalh' 
united Great Britain to the Continent. But in later times denudations and 
alterations of level have taken plac^, chiefly, I believe, great denudations 
of the chalk, and of the strata that cover the chalk, and then our island 
has become disunited from the mainland. And now, with all its numerous 
inlets, its great extent of coast, its admirable harbours, our country lies 
within the direct influence of the Gulf stream, w hich influences the whole 
climate of the west of Europe ; and we, a mixed race of people, Celt, Scan- 
dinavian, Saxon, Norman, more or less intermingled in blood, are so hap- 
pily placed that, in a great measure, we have the command of the com- 
merce of Europe, and send out our fleets of merchandise from every port. 
We are happy, in my opinion, above all things in this, that by denudation 
we have been dissevered from the continent of Europe, for thus it hap- 
pens that, uninfluenced by the immediate contact of hostile countries, and 
ahnost unbiassed by the influence of ])eo]iles of foreign blood, during the 
long course of 5^ear8 in which our country has never seen the foot of an 
invader, we have been enabled so to develope our own ideas of right and 
wrong, of political freedom and of political morality, that we now stand 
here, the freest country on the face of the globe, enjoying our privileges 
under the strongest and freest Government in the living w orld." 
In the objections we have made to certain topics, we have not wished 
those objections to stand against the book. They hold, one might say, 
equally against any other popular book on science at the present time, and 
rather against geologists generally than books at all. ' The Physical 
Geology and Geography of Great Britain ' is a little book deserving of 
more than one edition, and w;ll be deserving of very many when Professor 
Kamsay gives his mind to the two points we have criticized, especially 
the first, and rewrites those portions. It w ill be then a work that will 
