CLARK : GLACIAL SECTIONS. 
431 
30 feet down, and an angular fragment from a depth of 15 feet in 
shaft VI. Pieces of these I saw myself. Bits of so-called jet, 
probably lignite, were reported just above sand-bed E, or 40 feet 
from the surface. 
The chief interest of the sand-beds here disclosed lies in their 
discontinuity and the probable cause of the mysterious " bub- 
bling." Confining our attention to the 400 feet between shafts 
1. and IX., we have five distinct sand-beds ; for had any two been 
connected they must have been met again in the shafts or level 
drift. Beds B and C are the only exception, and at first I thought 
they might join below the drift. The pressure, however, produc- 
ing the " blower " in shaft V. when C was first tapped, would 
certainly have disappeared had the bed joined B, which was laid 
bare not 150 feet off. But not only must the five sand-beds be 
distinct from each other ; so also must the bed struck in shaft VII. 
from beds met in VI. or VIII., for otherwise such a rush of water, 
when nothing noticeable happened 50 feet on either side, is im- 
possible. These glacial beds must therefore consist of irregular 
deposits, — a series of false beddings upon a large scale. And yet 
true boulder clays, and scratched and polished boulders are as 
abundant as in glacial deposit in the neighbourhood. 
This fact gains added interest when the situation of the 
Friends' Retreat is considered. It lies half-a-mile E. of the Ouse, 
on the coutinuous ridge stretching in a large crescent from near 
the Ouse, below the junction with the Foss, to Sand Hutton, N.E. 
of York, a distance of 8 miles. In most parts it is marked by a 
steep slope on the convex side, which faces S. and averages about 
50 feet above the levels, which are 30 to 40 feet above the sea. 
The height a few yards \V. of these sections is 100 feet, and 119 
feet where the Stamford Bridge road crosses the ridge at Holtby. 
Again, almost in a line with it and with the same general 
direction, is the ridge to the \V. 'of the Ouse, along which the 
great south road runs as far as Bilborough, 6 miles to the S.W. 
Here it rises considerably above 100 feet, and is also crescent 
