IIS 
Mr. Lunn on the Strata of Cambridgeshire . 
this north-west side of the parish of Eltsley to Hilton, and thence 
through Passworth St. Everard to Passworth St. Agnes, and lastly 
arrive at Fenny Drayton ; here we are on the edge of the fens, and 
meet with the alluvial soil usually seen in similar situations. 
Not having strictly examined the country lower within the fens, 
I cannot precisely state whether appearances of regular stratification 
again present themselves. Throughout the whole of this sand many 
fragments of mineralized wood are found ; when dry they generally 
crumble into a fine power, but when moist and fresh from the earth 
are definite in form, and have the bark in the utmost state of preser- 
vation. 
The stratum of gait overlying the sand is of considerable extent ; 
it pervades the whole country from the line already traced out to the 
base of the Gogmagog hills ; its thickness is variable, but its irregu* 
larities may apparently all be accounted for, from inequalities of the 
surface of the ground, and to judge from an examination of the 
wells, I suppose the common surface of the sand and clay to form a 
very regularly inclined plane at the depth of about 200 or 220 feet 
from the common surface of the gait and the chalk. In the parish 
of Fenny Stanton a bed of clay rests upon the sand, and in the parish 
of Croxton the same takes place to a considerable extent. The 
chain well known by the name of the Gogmagog hills, consists of 
chalk resting on the clay ; detached masses of chalk are the Coach 
and Horses hill in Orwale, the summit of Madingley hill, and the 
Castle hill in Cambridge, which is a hummock of the lower chalk. 
The substances found in the clay of this county have all been dis- 
covered similarly imbedded. In sinking the few wells that pierce 
this stratum, splendid crystals of carbonate and sulphate of lime, 
with some small specimens of iron pyrites, have been thrown out. 
In the parish of Long Stow, near to the surface, are many beautiful 
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