Marcu 10, 1904] 
NATURE 
439 
GEOLOGICAL PHOTOGRAPHS. 
EOLOGISTS. will welcome the second issue of 
photographs by the committee of the British 
Association, appointed for the collection, preserv- 
ation, and systematic registration of photographs of 
geological interest. 
The circumstances which led to 
Fic. r.—Overfolding in Upper Carboniferous Limestone: South of Lough Shinny, Dublin. 
Photographed by Mr. J. A. Cunningham. 
the appointment of the committee were fully set forth 
in our review of the first issue (NaruRE, vol. Ixvii. p. | 
32, November, 1902). The value of these illustrations, 
both for teacher and student, is 
beyond question ; indeed, as furnish- 
ing material for comparative study 
they may not infrequently prove 
useful to the investigator also; it 
may not perhaps be regarded in the 
light of a compliment when it is 
added that there is at least one uni- 
versity professor who makes them 
serve for examination purposes, but 
this is a perhaps too practical in- 
quisitor, who, when weather per- 
mits, sets his examinees in front of 
previously unseen sections in the 
field. Every student, not to say 
teacher, of geology should have seen 
most of the phenomena somewhere 
or other which these photographs 
display, but it is very possible that 
not everyone has; it is even possible 
that some geologists have not seen 
a cirque, an esker, and a pitchstone- 
lava flow, t.e. not all three. 
Nothing, of course, can be a substi- 
tute for direct observation, but these 
photographs are certainly the next 
best thing to it. 
Their value is greatly enhanced by 
the fact that the descriptions have in 
each case been entrusted to a 
specialist familiar with the structure illustrated; we 
need only refer to Profs. Bonney, Lapworth, Marr, 
Watts and Garwood, not to mention many other 
familiar names, to show that the scientific description | 
NO. 1793. VOL. 69] + 
Fic. 2.—Stems of Lefidodendron Veltheimianuim, Sternb., 
Partick, Glasgow. 
of scenery has been placed in the best of hands. The 
subjects chosen for illustration cover a wide range; 
the Scur of Eigg, with its old lava flow filling a valley 
now exalted into a conspicuous hill, is shown from a 
point of view not often selected, and with excellent 
effect; the column of the Hemlock stone, very 
reminiscent of the Sahara, offers an admirable illus- 
tration of wind abrasion, though it 
is said to have been at one time mis- 
taken for a sea-stack; a cirque in 
Bala rocks is interesting both in 
itself and on account of the associ- 
ated glacial and fluviatile pheno- 
mena; the Cheddar ravine is a good 
example of an urroofed subterranean 
stream; and a boulder of Silurian 
rock resting on a glacially polished 
pedestal of mountain limestone 
affords a proof of the comparatively 
trivial amount of subaérial denuda- 
tion which has taken place since the 
close of the Glacial period; the cliffs 
of Muckross are an excellent study 
in jointing, here, as sharply shown 
as in a text-book diagram ; the raised 
beach at Saunton Down End, near 
Barnstaple, is probably one of the 
finest examples of such beaches to 
be found in the British Isles; the 
classic unconformity of Old Red 
Sandstone on Silurian rocks at 
Siccar Point, referred to by many of 
the old masters and figured by 
Lyell in his ‘‘ Elements,’’ is well de- 
scribéd by Prof. Lapworth; there is 
a good example of metamorphism 
produced by the great Whin sill; the 
rumbling hole in the ravine, Glenariff, co. Antrim, is 
a triumph of the photographer’s skill. 
From so much excellent material (the 
series com- 
wm situ: Victoria Park, 
Photographed by Mr. J. R. Stewart. 
near 
prises twenty-four photographs) it is difficult to choose, 
but with the kind permission of the photographers we 
select two examples for reproduction on a reduced 
scale, which may be taken as fair specimens of the 
