1815.] Transactions of the Geological Society, Vol. a: 57 
2000 yards broad. It lies over the old red sand-stone. There are 
ten beds of coal, which dip to the south, at an angle of about 30°, 
The other beds consist of slate-clay and bituminous shale, with 
iron-stone, sometimes in beds, sometimes in nodules. Above the 
first bed of coal there lie three beds of lime-stone, from two to six 
feet in thickness; of a reddish-brown colour, and without animal 
remains. The most important bed of coal is about the middle, and 
is four feet thick. On the north side of the field, about ten yards 
from fhe red sand-stone, a perpendicular bed of coal four feet thick 
rises to the surface. It terminates the coal. ‘The space between it 
and the red sand-stone being filled with irregular fragments of rock, 
every thing shows that this perpendicular bed is the same as the 
four-feet bed in the coal-field. Fourteen hundred yards to the 
north of Bradford there is another coal-field. They are divided 
from each other by old red sand-stone. Mr. Bakewell supposes that 
this sand-stone has been forced in horizontally between the two 
fields, and has occasioned the change in the direction of the four- 
feet bed. He supposes likewise that the mill-stone grit of Derby- 
shire is a continuation of the old red sand-stone. 
XII. Some Account of the Island of Teneriffe. By the Hon. 
Henry Grey Bennet, M.P. F.R.S. Pres. Geological Society.— 
This is the principal of the Canary Islands. It is about 70 miles 
long and 30 broad. A range of mountains runs through its centre. 
The Peak is a little to the south-west of the centre. Its height is 
about 12,500 feet. The whole of the island is volcanic, and all its 
rocks are lava. Mr. Bennet conceives that formerly a very large 
erater (twelve miles in diameter) existed, the sides of which, under 
the name Las Faldas, may be still traced a great way. Many 
extinct volcanoes are to be seen every where. The crater at the top 
of the Peak is but small, and seldom in activity. The lavas vary in 
their appearance; some are composed of horn-blende and felspar, 
without any foreign body; these are porphyritic ; some are com- 
posed of green-stone, and contain olivine, augite, zeolites; some 
are basaltic. These decompose the soonest, and constitute the 
most fertile soil. There is also pumice in abundance, tufa, ashes, 
and a lava exactly resembling obsidian. Mr. Bennet gives an 
interesting account of a journey which he made to the top of the 
Peak in 1810. 
XML. On the Junction of Trap and Sand-stone at Stirling 
Castle. By Dr. Macculloch.—The appearance here described was 
laid open to view by digging a new road across the Castle Hill. 
Horizontal beds of stand-stone occur, at first thick, but becoming 
thinner as they ascend. Green-stone lies over them, and several of 
the beds of sand-stone appear forcibly bent upwards at one end, 
while the green-stone has insinuated itself below them, and filled 
up the interval. ‘The sand-stone where in contact with the green- 
stone is converted into horn-stone, or rather flinty-slate. ‘This fact 
Dr. Macculloch brings forward as a confirmation of the Huttonian 
theory of the formation of green-stone, I have myself examined 
