WILLIAM SMITH : HIS MAPS AND MEMOIRS 
93 
Oxford, gives some farther account of Dr. Lister's ideas. It is dated 
London, March 13th, 1683-4. I received from Dr. Lister two schemes 
of the sands and clays found in England, made by himself about twenty 
years since. He mentioned besides the great advantage of a map of 
the earths peculiar to some places and countries ; he considers the sand 
and clays as two of the coats of the earth ; the sand, probably, the 
uppermost coat (for some reasons he gives), whence it comes to be 
washed to the body of rivers and the seashore. By this opinion, I 
perceive, may be given an account of sand-beds, too often attributed 
to the sea."* 
Dr. Lister's scheme for a map of England, distinguishing the soils 
and their boundaries by colours, has certainly the merit of priority. 
Sir Charles Lyell acknowledges that Lister was the first who was aware 
of the continuity over large districts of the principal gi*oups of strata 
in the British series, and who proposed the construction of regular 
geological maps. The scheme, however, was never carried out in his 
time. I 
Dr. Lister retained his love of geological studies to a late period of 
his life. In 1696, writing to his friend Thoresby, he says : "I desire 
to know if John Bolland of Halifax be alive. If so, I desire you will 
inquire of him where he had the blue or black slate-stone he sent me 
to York, in every leaf of which, were it cleft into never so thin sheets, 
there were very fair impressions only, and not the substance, of pecten- 
ites or scollop-like shells ; I imagine in some coal-pit about Halifax. 
If it can be found, I would have a good piece of it sent up to me by the 
carrier. 1 will most willingly and thankfully pay for it." J 
JOHN STEACHEY, 1719. 
In 1719 John Strachey contributed a paper on the Somersetshire 
Coal District to the Philosophical Transactions^ which was re-published 
* Ashmolean MSS., Xo. 1813. 
t The various soil maps appearing in the County Agricultural 
Surveys published by the Board of Agriculture, at the end of the 
eighteenth century and at the beginning of the nineteenth, carry 
out Lister's suggestion. 
% Thoresby's Correspondence, Vol. I., p. 259. Xo doubt it refers 
to shale with Aviculopecien. 
§ Vol. XXX., p. 968 ; another on the same sul^ject followed 
in 1725, loc. cit.. Vol. XXXL, p. 395. 
