XX 
PROCEEDINGS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
to which I wish to refer is the Photographic Exhibition, which 
has suggested to me the subject of my address for this evening, 
namely, 
GEOLOGY IN RELATION TO ART. 
During the last few months the citizens of Perth have had the 
privilege of seeing no less than three pictorial exhibitions in the new 
Sandeman Library, namely, a loan collection of oil paintings by 
some of the most famous masters of both ancient and modern 
schools; secondly, our own exhibition of photographs; and, lastly, 
a small but representative collection of water-colour drawings from 
South Kensington. Now, if we leave out of account the figure 
subjects in these three exhibitions, and consider only the landscapes, 
some interesting reflections suggest themselves when we compare the 
work of the brush and the work of the camera with a critical eye to 
details of scientific accuracy. I am not concerned for the present 
with the question as to which produces the more pleasing or the 
more artistic picture, but merely which is the more true to Nature. 
At first sight it may seem obvious that the work of the camera must 
be the more accurate, being an exact transcript of nature, as regards 
form at least; but this is not necessarily so. In the first place, the 
camera is apt to give a wrong impression of proportion, especially 
of distant objects, because the angle which, say, a mountain at ten 
miles’ distance, subtends in the camera is so very small as compared 
with that of a man at ten yards that the former becomes altogether 
dwarfed as compared with the latter. Then, again, the camera, 
although it does not make actual inaccuracies in form, very often 
fails to give due emphasis to important structural details in the land¬ 
scape, either from defects of focus or from insufficient distinction of 
tone. One example from my own experience will serve to illustrate 
this. In various parts of the Tay Valley there are very well pre¬ 
served remnants of the ancient river terraces, ranging up to over a 
hundred feet above the present level of the river. These terraces, 
to any one who knows where to look for them, are very clearly 
marked, and can be traced at intervals along the sides of the valley 
for many miles, but the moment the geologist points his camera at 
them they seem to shrink almost out of sight. This result is not 
due to the exaggerated imagination of the geologist, but to the in¬ 
ability of the camera to give a due sense of elevation, and to dis¬ 
tinguish between the various delicate tints of green and russet which 
make up the colouring of the hillside. Both of these mechanical 
errors could, of course, be easily rectified by an intelligent painter 
who knew enough of geology to correctly interpret the phenomena 
before him. The position, therefore, which I wish to prove is this, 
that the artist has it in his power to interpret nature even more faith¬ 
fully than the photographer, but that very frequently he fails to do so, 
for lack of a little elementary knowledge of natural science. 
If we examine an historical collection of paintings, arranged 
chronologically, we shall see that lack of scientific accuracy is much 
more obvious in the earlier than in the more recent schools. Indeed, 
