206 Field Meetings, 1907. 
of the Northampton Ironstone, and the Lower Estuarine beds, 
with the Lincolnshire limestone at the top; followed by the Great 
Oolite group consisting of the Upper Estuarine beds, the Great 
Oolite limestone and clay, with the independent band of 
the Cornbyvash at the top, beyond which we come to the 
Kellaways Rock and the Oxford Clay. All of these beds—from 
the Lincolnshire limestone on the west to the Oxford Clay on the 
east—lie exposed in near proximity to the village of Welton, 
which is built on the Great Oolite limestone. 
LINCOLNSHIRE LIMESTONE. 
Now of all the beds we have to deal with to-day the 
Lincolnshire limestone is the most important. It is ike a wedge 
between the Lower and Upper I'stuarine series, and consists of a 
compact QOolite limestone, which was deposited in a sea of 
moderate depth, and is the most characteristic of the Lincolnshire 
Oolite strata, belonging peculiarly to the County, from which it 
takes its name. It is in great demand for building purposes, as 
the Ancaster quarries in the south of the County testify, and, 
being of a porous nature, and lying on the impervious clays of the 
lias beneath (which, with the other strata in this eastern portion of 
our land, dips at a low angle, in a south-easterly direction) it 
acts like a sponge, retaining all the rain water that falls upon it, 
and forms the great water-bearing rock of the County. It reaches 
from Winteringham in the north to Stamford in the south, and is 
from 2 to 3 miles wide, and about 60 feet deep in the northern 
portion ; and from 4 to 6 miles wide, reaching to 130 feet deep in 
the southeyn area. In this latter district the supply of water is 
continuous, bursting out at the well-known ‘“‘ Well Head” spring 
at Bourne at the rate of 4 million gallons in 24 hours, but, in the 
northern part of the county the supply is intermittent, ranging 
(our President informs me), from 2 million gallons daily to a 
hundred thousand gallons, for 3 or 4 months in the year. This 
partial failure, in the supply in the north, is caused by intercala- 
tions of clayey beds, which impede, and partially bar the flow, and, 
probably form fissures in the limestone, through which the 
water escapes. A notable example of this irregular supply occurs 
in the village of Welton at the ‘Old Man’s Head” spring, which 
we shall see to-day. The Lincolnshire Limestone was, as I have 
