1824.] Geological Society. 463 



the greatest depth which has been pierced in that part of the 

 country, the following section was exhibited. From the depth of 

 2 feet to 29 feet, stiff reddish brown clay ; from thence to 35 

 feet, clays with septaria ; from thence to the depth of 180 feet, 

 blue clay, in which, in from 70 to 100 feet, were found various 

 shells and fragments of bituminous wood with iron pyrites ; 

 from 200 feet to the depth of 230 feet, blue clay, sometimes 

 sandy, in which numerous shells and bituminous wood occurred ; 

 at 230 feet, round black pebbles of flint like those of Blackheath 

 were found, this appearing to be the point of junction between 

 the London and plastic clays ; next a bed of sand, and after- 

 wards various coloured clays, were pierced ; at the depth of 

 270 feet, and continuing to 285 feet, sand and sandy clays 

 occur, the greater part of which is full of green earth exactly 

 resembling that of the oyster bed at Reading. The paper was 

 accompanied by specimens of each of these strata. 



A letter was read from Alexander Gordon, Esq. to D. 

 Gordon, Esq. of Abergeldie, describing three successive forests 

 of fir imbedded in a peat moss ; accompanied by specimens. 



The moss of Auldguissackin Aberdeenshire, Scotland, presents 

 an inclined plane of rather uneven surface, and varies in depth 

 from 18 inches to 10 feet from the lower part of the hill to the 

 river. 



Upon digging up the ground in two different parts of the 

 moss, large roots of Scotch fir trees were found about one foot 

 below the ordinary average level of the moss. Below the bot- 

 toms of these roots there is a stratum of about a foot and a half 

 of moss below which other roots or trunks appeared, and on 

 digging still further down (about six or seven feet below the or- 

 dinary level of the moss), a third set of roots and truncated 

 stems of trees were discovered. 



It appeared to Mr. Gordon impossible that these roots could 

 have supported different trees, all growing at the same time, for 

 the distinct ramifications of these (horizontally like Scotch firs 

 at the present day), are bedded in moss perpendicularly above 

 each other. 



April 23. — A paper was read, entitled " Some Observations 

 on the Lakes of Canada, their Shores, Communications, &c. by 

 Lieut. Portlock, RE." 



In this memoir the author describes the various nature of the 

 shore, of Lakes Huron, Michigan, Erie, and the other lakes of 

 Canada, and annexes a plan, in which a tabular view is pre- 

 sented of the comparative level of these lakes and their com- 

 munications with each other. At the falls of Niagara, he ob- 

 serves, the upper stratum is a firm compact limestone resting on 

 strata of a very schistose nature. It is not by erosion of the 

 surface that the falls are made to recede, but the waters, after 

 falling 150 feet, strike the bottom, and are reduced to foam ; 

 they are then driven up into the air far above the rock whence 



