‘149 
small effect Mr. Buddle explains by showing, that the railway passes 
near one end of the excavated tract, and that metal-stone predomi- 
nates over sandstone in the superincumbent strata. ‘The working of 
the five-quarter seam is now in progress, and the effects occasioned 
by the removal of the three lower seams are well exposed. Innu- 
merable vertical cracks, pass through the coal, its roof and pavement, 
but they.are perfectly close except around the margin of the settle- 
ment. Along this line the strata are bent down, the cracks in the 
pavement are rrequently open, forming considerable fissures, the coal 
is splintered, and the roof-stone is shattered. In the interior of the 
settlement the pavement is as level and smooth as if it had never been 
disturbed, and the cracks are quite close, passing through the seam 
without splintering it or producing any effect except that of render- 
ing it tougher, or, in the language of the colliers, ‘‘ woody.” This 
effect, Mr. Buddle conceives, may be attributed to the escape of the 
gas, and he states that it is sometimes produced by other operations, 
when the coal is said to be ‘‘ winded.” ‘The smoothness of the pave- 
ment, he is of opinion, is due to the direct downward pressure of the 
superincumbent mass; and he states, that he has never noticed any 
tendency to a sliding or sideway movement in any subsidence of 
strata occasioned by the working of the coal, except the slight ob- 
liquity occasioned by the offbreak at the sides of the settlement. 
A paper was afterwards read, ‘‘ On the relative ages of the tertiary 
and post-tertiary deposits of the Basin of the Clyde,” by James 
Smith, Esq., of Jordan Hill, F.G.S. 
In former memoirs, Mr. Smith described the indications which he 
had observed of changes in the relative level of sea and land in the 
basin of the Clyde, by which deposits had been laid dry during an 
extremely recent geological epoch *; and the evidences adduced by 
the arctic character of several of the shells, that the climate of Scot- 
land was colder while these beds were accumulating than it is at pre- 
sentt. In this paper he confines his remarks to the results of sub- 
sequent observations, which prove, that in these comparative modern 
deposits there are two distinct formations, differing in climate and 
the character of their fauna, and separated by a wide interval of time. 
In the lower or older of these formations, Mr. Smith has found from 
10 to 15 per cent. of extinct or unknown species, and he accordingly 
places it in Mr. Lyell’s proposed pleistocene system; whilst in the 
upper or newer he has found only one species which exists in the 
present seas, and he accordingly ranges it among the post-tertiary 
formations of that author. Both these deposits, however, are an- 
terior to the recent or human period. 
In the lower or pleistocene formation, Mr. Smith includes the 
“till” or unstratified accumulation of clay and boulders, and the 
overlying beds of sand, gravel, and clay containing a mixture of un- 
known species of shells. He is of opinion that the beds presenting 
* Proceedings, vol. ii. p. 427. 
7 Ibid. vol. iii. p. 118. See also Mr. Smith’s paper on the Wernerian, 
Society's Transactions, vol. viii. 
