280 
Farming of Biichiiighamshire. 
Lunatic Asylum, though it has failed to produce an adequate sup- 
ply of water, is interesting in its geological results. The well in 
question is more than 550 feet deep. The first 20 feet were 
lound to consist of limestone and yellow sand, and then, with the 
exception of a few narrow bands of limestone, lliere appeared a 
solid bed of clay more than 500 feet thick. At the distance of 
530 feet from the surface the great oolite was found, and after 
sinking- into that rock about 30 feet the present meagre supply 
of water is obtained. This proves the total absence of the 
Oxford oolite and calcareous grits. 
We have now arrived at the grand feature of the county of 
Bucks, the Vale of Aylesbury. Much has been written and 
much more said about this celebrated tract of country, and truly 
on looking at it from Brill Hill at one extremity, or from Whit- 
cliurch on the other, it might be called a land flowing with milk 
and honey. There is a large district reaching from Aylesbury 
almost to Winslow, to various parts of which the rich title of the 
Vale of Aylesbury has been applied. Without wishing to be 
particular as to words, it might be said that the term vale could 
not properly be applied to any portion of the district. It might 
be described as an undulating plain, from which now and then 
rise patches of elevated land, which are mostly capped with the 
Portland stone before mentioned. The land on which it really 
rests is marked on the map as Kimmcridge clay, but again 
learned professors differ ; for while Phillips and Conybeare say 
that there is no such clay in Bucks, and further assert that the 
cjryphcca dilatata, the characteristic shell of the Oxford clay, has 
been traced to the very junction with the Portland stone at 
Waddesden Hill, Smith, the father of geologists, upholds the 
opinion first recorded. However, all parties agree that tiie 
Kimmeridge clay does not extend northward beyond the Vale 
of A^ylesbury, and that the clay soils about Fenny Stratford are 
essentially Oxford clay. As farmers we can well afford to let 
this knotty point be settled by those capable of judging, for there 
are parts of the county where the gault, the Kimmeridge and 
Oxford clays, run into each other, and no practical valuer would 
discern the transition, or make a difference of Qd. an acre one way 
or the other. The real difference of the land does not depend on 
the peculiar clay stratum underlying it, but on the quality of the 
dark soil and rich vegetable mould which covers the clay. The 
Kimmeridge or Oaktree clay ccmsists of beds of blue, slaty, or 
greyish clay, containing selenite. The Oxford or Church clay 
has beds of immense thickness of a tenacious and adhesive clay 
of a dark blue colour, which turn brown on exposure, and con- 
tain arglUo-calcareous geodes and septaria, commonly called 
turtle-stones. Tliere is not much to choose between these 
