Farming of 0.rfordshire. 107 
With the exception of <i few isolated patches such as Islip, 
which is a protuberance of the great oolite, a large portion of the 
ground around Oxford is occupied by the Oxford clay. The 
city itself stands upon a bed of gravel, which is about ten feet 
thick, and from it is derived the supply of spring water, as the 
rain which soaks into the gravel is retained by the subjacent 
clay. Tliis gravel, though it differs very little, if at all, from 
that before mentioned as regards its agricultural character, par- 
takes more of the nature of the northern strata, and extends to 
Marston, Summeistown, and Wolvercot. The Oxford clay is 
first found south of the city, in the meadows of Sandford, and 
stretches as far north as Bicester, where the dairy grounds ex- 
hibit a fair specimen of sheer Oxford clay. Although it is a most 
stubborn soil to work, yet frost reduces it to a powder, and it is 
so loose and dusty in the spring that young wheats and clovers 
are in danger of being blown out. There are many beds of 
gravel with quartz pebbles, sometimes amalgamated together. 
Here the soil is more friable and produces fair crops, is easily 
tilled, and will carry sheep. This is also the case where the 
sand of the calcareous grit washes over the clay, as at Holton. 
Most of this formation is in grass ; and there are some rich pro- 
ductive pastures, especially where the alluvial deposits occur, as 
the grazing grounds about Water Eaton will show. Again, 
there are others producing a little poor rough grass, and covered 
with ant-hills. This formation is mostly flat, but attains to a 
considerable elevation at Stowe Wood. At Oxford, which is 
one of its lowest points, it is 265 feet in depth. In digging 
deeply in many parts of this stratum a bituminous shale is 
found, and at Eynsham Heath and other spots some persons 
were misled into the persuasion that coal was close by, and in- 
volved themselves in unprofitable speculations in the search of 
that mineral : one instance among many which might be cited 
of the false impressions which a very superficial knowledge of 
geological facts, and the laws deducible from them, would have 
shown to be from the first utterly groundless and chimerical. 
The whole of the country stretching from the Chiltern Hills to 
the northern boundaries of the Oxford clay was classed by 
Arthur Young as " miscellaneous loams," and contains 1GG,400 
acres. 
The region north of the Oxford clav is occupied by the great 
oolite, and forms that extensive portion of the county known as 
the Stoncbrash district; it is flat table-land, with a broken edge, 
and is distinguished by its large fields and stone walls. This 
stratum is formed of various beds of oolitic shelly stone, some 
so thin that they produce Stonesfield slates ; while others are of 
considerable thickness, and form a compact building stone. 
