iv 9) 
Cs 
1817.] during the Year 1816. 
1, Central granite. 
2. Gneiss and granite. 
3. Green-slate. 
4. Gneiss. 
5. Mica-slate. 
6. Clay- -slate. 
8. Country round Birmingnam.—In the Annals, viii. 161, I have 
al a sketch of the structure of the country round Birmingham. 
The lowest formation known is a floetz lime-stone, which rises 
through the surface, and forms hills at Dudley, and is quarried 
likewise near Walsal. Over this lies the coal formation which 
begins at Stourbridge, and extends about 16 miles north-east, with 
a breadth of about four miles. Over the coal formation lies a range 
of low basalt hills, extending from Dudley towards Hales Owen. 
The county of Warwick, and that part of Worcester which lies 
near it, consist of a red sand or sand-stone covering the coal, and 
full of pebbles which appear water-worn. ‘The Birmingham coal, 
as far as | know, constitutes the only well-known example in Great 
Britain of the coal formation lying immediately over floetz lime- 
stone. It would be an object of some interest to determine whether 
the same position exists in any other coal-field. 
4. Cumberland.—Though this county has been visited by many 
miteralogists, We are not yet in possession of a correct delineation 
of its structure. On that account [ think it worth while to mention 
a notice respecting some of the rocks which occur in this county, 
published in the Philosophical Magazine, xlvii. 41. Itis not of a 
nature to be epitomized. I must, therefore, satisfy myself with 
referring to it. But it will be of considerable use to those mine- 
ralogists who may hereafter undertake a description of this intricate 
country. 1 believe a good deal of the intricacy arises from the 
porphyry which caps many of the mountains, and which changes 
its aspect so much in different places, that considerable attention is 
requisite in order to recognize it. 
5. Level of the Caspian and Black Sea.—From the observations 
of Engelhardt and Parrot, made with great care, it appears that the 
surface of the Caspian is Jower than that of the Black Sea by about 
YS metres, or 324°7 English feet. 
6. Matrix of Cinnamon Stone.—I have given a short description 
of the roek, in which the einnamon stone occurs in the island of 
Ceylon, from a specimen which Mr. Mawe was so obliging as to 
send me. It is an aggregate of tabular spar (schaalstein), quartz, 
and cinnamon-stone. ‘Phe rock is very beautiful. It is not unlikely 
that it may in situ be a quartz rock, in which the tabular spar and 
cinnamon stone are imbedded; but this can only be verified by an 
examination on the spot. It is to be expected that Dr. John Davy, 
who I believe has gone to Ceylon, will shortly furnish valuable in- 
formation respecting the structure of this curious island. (See 
Annals, vii, 242.) 
7. Soda Lake in South America.—It appears from a paper pub- 
F 2 
