338 
Society it would be proposed that the Council have power to 
fix the June meeting so as to follow the meetino- of the 
British Association in Manchester, in order that the meeting 
might have the presence of a number of distinguished 
geologists. Dr. Buckland had promised to attend. 
Mr. Wilson then referred the meeting to Mr. Greenough's 
splendid Geological Map of England and Wales, which 
was exhibited in the room, and which the society had 
just purchased. 
OBSERVATIONS ON THE YORKSHIRE DRIFT AND GRAVEL, 
BY JOSEPH TRAVIS CLAY, ESQ., RASTRICK. 
At the June meeting of this Society, I read a short paper 
on the occurrence of boulders of granite in the vale of 
the Calder, near Halifax, when I alluded to those deposits 
of clay wdth erratic boulders which are generally known by 
the appellation of Diluvium, or Drift. 
I have now to request your attention to a more particular 
inquiry into this formation, which is interesting both as in- 
dicative of considerable changes having taken place at a 
very recent geological period, and also from the great dis- 
cussion and various theories to which it has given rise. 
The accumulations of removed matter which occur very 
extensively, not only in many parts of Great Britain and the 
northern countries of Europe, but also on the continent of 
America, under all circumstances maintain a great similarity 
of constitution — their general character being the assem- 
blage of pebbles and boulders of the harder rocks (more 
or less rounded by attrition), dispersed amidst a mass of 
clay or sand, without any appearance of stratification or 
order. This confused disposition of the fragments has 
given rise to the idea that a force of such power has been 
