60 
the tenacious clays and rocks of the Forest Marble formation 
and the Fuller’s Earth, which thus separates two distinctive 
subterranean waters, unless and until they are brought into 
communication by the numerous faults that intersect the valley, 
which is most probably the case. The artesian character 
assumed by these waters is due to the imprisonment described. 
It was at first suggested to me by the strong up-rise visible in 
the springs at Boxwell withy bed, and by the large volume of 
water always encountered in excavations made in the Ciren- 
cester gravel bed, which indicated a continuous ‘‘ feed”? from 
springs passing into it upwards, through the faults to which I 
have referred. 
The feasibility of obtaining an artesian supply at Cirencester 
was tested by the late Earl Baruurst, in 1871-72, at whose cost 
a boring was sunk, under my direction, at the Barton, a section 
of which, showing particulars of the ground pierced, is given. 
(Drawing No. 4.) This boring, although but little more than 
experimental, was completely successful in developing a supply 
of pure water, suitable for drinking, culinary, and domestic 
purposes; for on January 6th, 1872, at 91 ft. 6 ins. below the’ 
surface of the meadow, such water was reached in soft white 
rock in the Great Oolite, it immediately ascended the bore with 
much force, overflowing above the surface with a discharge of 
18 gallons per minute. Subsequently the Cirencester Water 
Works Company have obtained an abundant supply of the best 
and purest water from a similar source at a greater depth. The 
section of a boring recently made by them at their works at 
Lewis Lane is given. (Drawing No. 4.) 
The drainage area to Colesbourne is about 16 miles, pro- 
ducing a flow of 312 cu. ft. per minute, nearly 20cu. ft. flow 
per sq. mile, being much in excess of the Thames standard, 
12 cu. ft. per sq. mile. 
Before proceeding to Swindon, and the interesting sinking 
now being made by the Great Western Railway Company, I 
will say but a few words about the rivers Ray and Cole, the 
Shire Ditch and Bide Mill Brook, with their respective tribu- 
taries, the collective drainage area of which streams amounts to 
