"معاملات الجمعية الجغرافية في بومباي، من يناير ١٨٤٧ حتى مايو ١٨٤٩. تحرير السكرتير. المجلد VIII." [‎١‎٧] (٤٩٦/٣٢)

XVII
Caves are abundant in most parts of tbe world. There seem only two classes
of causes by which they can have been formed—the sudden disruption of rocks by
violence after their induration, or erosion by air or water The aspect of the
rock itself will always indicate unmistakeably and at once any circumstances in
which the first cause has assisted:—decay and erosion by the action of the air or
of moisture, can only occur where the matter affected is soft and easily decomposed.
Where neither of these explain the phenomenon, its appearance can only be ac
counted for by the operation of water in large masses. The aspect of the country
will indicate whether this has risen from the sea, from lakes, or from rivers.
I have not had it in my power to refer this letter to the Committee of the Geo
graphical Society, as I was apprehensive it might thereby have been too late for
your despatch; and though I am persuaded the views expressed in it will be
adopted by them, I am not at present entitled to set them forth as stamped with
the weight of their authority.
I have &c. (Signed) Geo. Buist, Secretary to the Society.
Geographical Society’s Booms, Town Hall, Bombay, 7th September, 1847.
St. Andrews, July Iftth, 1847.
My dear Sir, —Ibeg to address you on a subject which I think will be interesting
to you, and on which I crave your kind assistance. For about a year past I Lave
given most of my spare time to the examination of Ancient Beaches. I have found
and measured them all round this island, and even in Ireland and France. Every
where there is a series at uniform heights, leading to the unexpected deduction that
the change of relative level of sea and land, by whatever means accomplished, was
a process observing equability over a very large region. I read a paper on the
subject at the Oxford meeting of the British Association 5 but the obvious bearing
of the facts against prevalent theories caused them to be characterised by Buckland,
Lodgewick, &c., as “ an audacious generalization,” which I shall perhaps have
occasion by and bye to remark upon as an exceedingly good joke. Being only
stimulated by this opposition to further research in the same line, I am now en
quiring after proofs of extended uniformity in Norway and America; and the facts
tending to this effect which I have already obtained, would probably surprise you
not a little. There are undoubtedly terraces in North America from 60 up to
1000 feet, coming almost to a perfect uniformity with those I have discovered in
Britain. I do not yet say that they are identical; but the appearances at present
are all that way.
It may be a romantic and disappointing attempt, but I nevertheless wish you
will look for terraces in your part of the earth, and have a few good specimens
measured. I should not say disappointing, for, though they were found to be en
tirely discrepant, it were well to know so much ; and even in themselves they would
form a curious addition to our geological knowledge.—You have given some attention