36 



TEE GEOLOGIST. 



Yorkshire. Wilts and Gloucestershire. 



Cornbrash . . Cornbrasli. 



Upper Shale and Sandstone Forest Marble, Bradford Clay. 



Bath Oolite . . Bath Oolite. 



Lower Shale and Sandstone Fuller's Earth. 



Inferior Oolite . . Inferior Oolite. 



Both the upper and lower shales and sandstone are of fresh-water or estuary 

 origin, and contain numerous plants, with Bquisetum. columnare, sometimes 

 retaining its erect position, and occasional thin seams o'f imperfect coal. The 

 upper series may be observed to the south of Scarboro', in Gristhorpe Bay. 

 At Stainton Dale and Peak Hill, which forms the south side of Robin Hood's 

 Bay, the lower series attain their greatest development, and are upwards of 

 four hundred feet in thickness. At this spot the whole of the strata, from the 

 Bath Oolite to the Upper Lias inclusive, may be observed in one grand section, 

 which attains an elevation of nearly six hundred feet above the beach. The 

 Upper Lias forms an undercliff, from which the superincumbent Lower Oolite 

 strata rise almost perpendicularly, and are all but inaccessible. 



NOTES AND QUERIES. 



An "Early English" view.oe Adhemar's Theory. — We are justified in 

 designating many geological notions, introduced fifty years ago, as "Early 

 English ;" for the like simple form of a first-pointed window they have served 

 the framework for an after-filling of thought-tracery, and have not suffered 

 an obscuration from subsequent additions. This is particularily noticeable in 

 theoretical geology ; no theory, either relating to physical or palseontological 

 geology has appeared upon the stage in its full dimensions, but like other great 

 results of thought, has been built up slowly and added to in after times. As 

 an example of this, I wish to bring before the notice of your readers, an early 

 germ of the "Periodicyof Deluges," theory of M. Adhemar. I find it as an 

 article in an old magazine, bearing date "February 4, 1812." The article is 

 a long one, but the following intelligible resume concludes it : — 



" The following are the general deductions, which the preceding facts and 

 reasonings seem to establish. 



1. That the changes upon the earth's surface, and the consequent phenomena 

 of the strata and the fossil remains, are referable to certain known motions of 

 the earth as a planet. 



2. That those motions are the revolution of the perihelion point, (a line of 

 apsides,) in twenty thousand nine hundred years, producing opposite effects in 

 both hemispheres every ten thousand four hundred and fifty years, and the 

 diminishing obliquity of the ecliptic at the present rate of "a "degree in six 

 thousand nine hundred years. 



3. That the perihelion forces, in varying their declination, gradually accumu- 

 late the seas in that hemisphere to which they are perpendicular ; and that the 

 gradual accumulation takes place in either hemisphere, while the point of the 

 maxima advances through twenty degrees of decimation in a period of about 

 three thousand four hundred and eighty eight years. 



4. Thai the accumulation of the seas in that hemisphere, in which lies the 

 direction of the perihelion parallel is a consequence of the accumulated centri- 

 petal force, which produces or requires a corresponding increase in the centrifugal 

 force, or oscillating momentum of the waters. 



