382 
POPULAR SCIENCE REVIEW. 
are both more frequent, and blow steadily up a continuous slope from the 
sea, while the latter are little felt near the lower ground, the ridge of the 
hill serving as a shelter, the result is an unmistakeable advance inland, 
and farms, houses, and even villages, become gradually obliterated. Much 
grass, of that peculiar kind that roots in loose sand, has been allowed to 
grow, but it is quite insufficient to check the evil.” 
We must not, however, dwell longer on the scenic attractions of the 
Channel Islands, our object being to notice, in connection with the work 
whose title is appended to this paper, some of those features which possess 
special interest for the naturalist. We have been fortunate enough to have 
spent two very delightful summer holidays in investigating several 
branches of their natural history, and can cordially recommend any 
brother naturalist to whom the islands are unknown, to go and do like- 
wise. Whatever branch of science occupies his attention, he may be 
pretty sure of finding abundant material for study. The islands are, 
moreover, very easy of access, and the expense of living, though not so 
exceptional ly small, as in the good old times, when tourists were few and 
far between, is, at any rate, very much less than at most sea-side resorts. 
It is interesting to note that the most picturesque and characteristic 
scenery of the Channel Islands — the caverns, detached pinnacles, and 
“ creux,” are at once the result and the evidence of a constantly progressive 
destruction. Professor Ansted thus sums up the conditions under which 
these results are produced 
“Nowhere on our shores is the tidal wave so powerful, nowhere are the 
storm waves so frequent ; nowhere is there a coast consisting of material 
in which so much rock of extreme hardness is penetrated so thoroughly 
with veins of softer material. The very hardness of the granite, where it 
is hard, produces an unusual destruction of the softer veins ; for, as already 
explained, every fragment removed becomes a hammer, helping to under- 
mine what is left. Whenever one hard mass is thrown down and broken 
up, another is soon attacked ; and thus a perpetual and rapid destruction 
is caused, increasing constantly in area, and not diminishing in intensity.” 
This destruction goes on so rapidly as materially to alter the rock sur- 
faces in a very short lapse of time ; and it is certain that in historic times 
the general aspect and contour of the islands must have undergone very 
material change. Nor is this the only actively destructive agent. Earth- 
quakes have been frequently felt, and even so lately as 1843 and 1853 
shocks so violent as to cause great alarm have occurred. 
The tides in the Channel Islands are the perplexity of dredgers, and add 
much by their violence and variable direction to the dangers of the coast. 
On this account, indeed, it is quite unsafe to venture on dredging or any 
other kind of boating without the help of experienced sailors. In many 
places the rush of the tide is tremendous. Through the narrow channel, 
for instance, between Sark and the Gouliot Rock, it sets with the impe- 
tuosity of a great river in flood ; and we well remember that in passing 
through with a fresh breeze and all sail set, it was all our boat could do to 
make head against the stream. A most beautiful and accurate view of this 
spot is given by Mr. Naftel at page 81. The complicated character of the 
tides will be understood from the following remarks : — 
