488 LOWER OOLITIC ROCKS OF ENGLAND : 
Fuller s Earth. 
In the Fuller's Earth or Fullonian formation, between the 
Inferior and Great Oolite of Somersetshire and Gloucestershire 
there occur beds of economic Fuller's Earth. 
This Fuller's Earth, as previously described, is a greenish or 
bluish-grey calcareous clay that weathers brown ; and so far as 
can be judged, it occurs sometimes in impersistent and lenticular 
masses that attain in places a thickness of 5 or 6 feet ; in other 
cases it gradually passes into ordinary marl or clay. Its Koapy 
character is considered to be due to the presence of a small pro- 
portion of magnesia ; while its detersive property is attributed 
to the alumina. 
From the fact of its imbibing oily matter, it has been extensively used 
for cleansing woollen cloths, in the factories that in the West of England 
were at one time in a more nourishing state than they now are.* 
Fuller's Earth is largely used for washing rugs and blankets, carpet and 
worsted yarns, woollen and worsted cloths and silk, and other fabrics in 
the course of manufacture and dyeing. In addition to this use there is a 
great demand for the Earth (in a highly powdered and refined condition) 
for chemical and toilet purposes, and also in various states for refining 
oils, tallows, fats, and wax, and for numerous other purposes. 
The value of Fuller's Earth has long been known, it is the Greta Gimolia 
of Pliny, and little more than a hundred years ago a special Act of 
Parliament was passed to prohibit the exportation .f 
Near Bath, Bine and Yellow Fuller's Earth is obtained ; the latter being 
the weathered portion obtained near the surface. The Yellow Earth is 
sometimes este'emed the better, but according to notes made by H. W. 
Bristow, the Blue Earth " is frequently of as good a quality as the 
yellow for particular purposes, as in fulling coarse cloths." The "veins " 
vary in thickness from about 18 inches to 5 feet. " If good, a vein 18 
inches in thickness could be worked with profit, but not if of less 
thickness. Sometimes the vein stops suddenly, at others it gradually 
thins out." 
There appears to be a gradation from Earth having fulling properties, 
to ordinary claye, through varieties known as Bastard Fuller's Earth. 
Hence the earth obtained at different places is subject to variation in 
quality as well as in thickness. 
The Fuller's Earth is worked in some cases, as at Combe Hay, by means 
of shafts sunk to depths of from 20 to 30 feet, when the earth is procured 
from levels driven in different directions. The shafts are sunk at or near 
the base of the Great Oolite. In other cases, as at Midford and Wellow, 
the earth is obtained from levels driven into the outcrop of the Fuller's 
Earth : the galleries being from 4 to 6 feet in height. (See pp. 240-243.) 
Through the kindness of Mr. H. N. Garrett (Proprietor of the Midford 
Fuller's Earth Works), I was enabled to see the various processes under- 
gone by the Fuller's Earth clay, to render it marketable. The raw earth 
is dug in the hill-side not far from the Cross Keys Inn, and it is conveyed 
in trucks down a steep incline to a " Pug-mill." There it is ground up, 
with about three times its own bulk of water. The compound, known 
as " slurry," is then turned into a series of little tanks or " catch-pits," 
and while the fine Fuller's Earth remains in a state of suspension, the 
coarser particles sink to the bottom. The liquid, which still contains 
"impurities," is then allowed to run into a long earthenware drain, laid 
* The Fuller's Earth has heen much used in the Cloth Mills at Frome, Bradford- 
on-Avon, Stroud, and other places. There are old Fulling Mills, west of Broughton, 
near Banbury, and west of Blakesley, near Towcester. 
f Jameson, Mineralogy, ed. 3., vol ii. pp. 302, 303 ; and J, Woodward, Nat. Hist. 
Poss. Eng., 1729, Part 1, p. 5. 
