30 DE RANCE : UNDERGROUND WATERS IN LINCOLNSHIRE. 
Green Man. Its breaking out at a higher level than most of the 
other springs appears to be due to the obstruction to the passage of 
water down the dip of the strata, caused by the N.W. and S.E. 
fault ranging between Dunston and Nocton. 
At the Green Man, 154 feet above the mean sea-level, there is a 
well 25 feet deep with bore-hole, the water at time of visit (July, 1891) 
did not rise to bottom of well. A slimy pond by the roadside 
was used 40 years ago, and has a puddled bottom ; no spring 
occurs. 
At Warren House there is a double bucket well ; the water flows 
strongly to the south-east. The water is lifted by horse-power. A 
quarter of a mile to the north is a deep dug combe, pointing to a 
seasonal variation in the level of the plane of saturation. This is 
also apparent in the park approaching Blank! ey Hall, where a combe 
has evidently been recently occupied by a stream, now (July) reduced 
to a single clear, rather shallow, pond. 
Shallow wells, with ordinary pumps, supply the village of 
Blankney. 
Traversing the same district along the strike of the Lincolnshire 
Limestone, from Lincoln southwards along Ermine Street, at the 
cottage 4£ miles south of the city, water stands at 35 feet from the 
surface, and yields a copious (cottage) supply. This is also the case 
at the cottage at the corner of bye-road just north of the monument ; 
the water level is just 30 feet from the surface and varies about five 
feet. The Pillar is 198 feet above the mean sea level, so that the 
water level is 161 feet above the same. At the first cottage south of 
the monument a single bucket-pump reaches water, and a very small 
stream was flowing down the combe between. With the exception of 
the above well the whole of the facts observed south of Lincoln, in 
the Lincolnshire Limestone, point to less local irregularities of water 
level, and a more uniform eastern trend than is observable north of 
the city, where the limestone is broken up by hard bands, probably 
of ironstone. The aggregate thickness of the limestone, as measured 
by the Geological Survey at Washingborough, amounts to 65 feet, in 
which occur the following inij)ermeable beds : — 
