126 Mr. Farey’s Notes on Mr. Bakewell’s Geology. 
[P.202] The principal masses in ‘this conglomerate are qtiartZ 
grains of very various sizes, variously intermixed with masses 
of white Chert, of Jasper, of Slate, &c. &c. It forms re- 
sular beds, dipping easily SE, and passing under the very 
reralar black Marble Rock (in which there is a considerable 
Quarry and Lime-Kilns called Cwaise-bangor, about 7. 
NNE) constituting the lower part of the Limestone floor or 
trough’ to the Coal-measures, mentioned in my note on 
p. 108. In general, where I had opportunities of examining 
this grifstone below the black Limestone Rock, it consisted 
of very variable coarse Grit- -stone, but in athe: places, the 
same had a few masses of Jasper in it (as I had noticed in 
South-Wales), masses of Chert in others, and on the W 
side of Nant-hoorva Quarry, +m. SW of Llangefni, the 
masses of Chert are large, resting on coarse Slate, and seem 
to graduate or pass into Ji asper, as they do also on the SW 
side of Graig-fawr Rock ENE of the Town. I much wish to 
eall the attention of Geological observers, to the careful ex- 
amination of this and other variable Rocks, as presenting 
matter of important consideration, on the formation of 
strata: Mr. Jameson’s late opinions and mine, seem very 
nearly to coincide, as to their cotemporary formation. 
1. 18 and 19, more properly to the vegetable +.—t Rep. le 
311, Mont. Mag. XXXili. p. O15. 
205, 1. 16, on this coast*.—* Without doubt the ground has 
sunk, comparativély at least, on all the British Coasts, see 
Encroachment of the Sea in “Dr. Rees’s Cyclopedia, my Ist 
Letter, vol. xlii. p. 58, and Note on p. ll. 
206, 1. 3, than the Geologist *.—* No true theory of the Earth - 
or system of Geology will ever be produced, which does not 
embrace a knowledge of ‘alluvial ground,” so universally 
spread, equally or more intimate, than with all the ‘ primi- 
tive and transition” countries in the World; because-allu- 
vium, besides being vastly more spread, indicates later ope- 
rations on our Planet, and more within the reach of our in- 
vestigations, than the formation of Mountains; the force 
of this remark Mr. B. may comprehend, from my Notes on 
pages 16, 175, 200, &c. 
J. 12 and 13, and explained the principles + ae In 1784, 
Dr. James Anderson clearly explained the general principles 
of draining Land (in his Essays, i. 150), more of these 
principles, “indeed, than Mr. Joseph Elkington knew, in 1794 
(Rep. ii. 368, and P. M. xii. p. 215)? Years before either 
of which periods, they were practically known to Mr. 
William Hart (Rep. ii. 371) and others, engaged exten- 
sively in draining, for Proprietors and Occupiers of Land im 
_ Various 
* 
