184. 
explained” what he actually intended by this expression. 
Certainly not in the paper in question; nor can I find any 
further allusion to the question in his subsequent writings. 
We have fortunately his admirable section from Birdlip to 
Swindon, passing through Cirencester, the lines of which are 
taken along the Roman roads through the town. [The original 
coloured drawing is in the collection of diagrams and sections 
of the Royal Agricultural College. | 
This section represents the fault at Stratton as throwing 
down the Great Oolite and Forest Marble some 25 ft. to 40 ft. 
It seems pretty clear that by thé term “valley of depres- 
sion” he intended no more than to graphically describe this 
faulting down of the clays of the Forest Marble to form the 
floor of impervious rock beneath the gravels that underlie the 
town. 
For the past eight or nine years I have been gradually 
collecting materials for a more exhaustive study of the Forest 
Marble of the district than has yet been made, and the clay 
floor of the valley has always presented an unsolved puzzle. 
The opinion of Buckman, as expressed by his general 
section, is that which hasheen-generally followed by subsequent 
writers, though there has always been a minor conflict on the 
question of the Junction Beds of the Great Oolite and Forest 
Marble. I have been informed by a student of the late Prof. 
John Morris that he held the view that the shallow subterranean 
water of Cirencester was derived from the Fuller’s Earth, and 
that this opinion was founded on the chemical composition of 
the water. He has, however, left no writing on the subject, 
and in the absence of reasons we are precluded from entertain- 
ing this idea. It may be that he felt dissatisfied with Buckman’s 
explanation. Whether that be so or not, I had for some years 
formed a strong opinion that the faulting down of the Forest 
Marble alone was not a satisfactory explanation of our shallow 
town-well supply. My reasons were chiefly these. The more 
one becomes acquainted with the Forest Marble, the more 
variable and unstable do its numerous clay beds appear. At 
Kemble, as described by Buckman (loc. cit.), the top-most bed 
