TO make several corrections for temperature, diurnal 
variation, &c. In the experiment made, tbe reading: at the 
lower station was 30 124 inches, and at the upper 29 6G8, 
.showing a difference of level equivalent to 899 feet. Several 
aneroid barometers were compared at the same time, one of 
them giving a result which only differed by six feet from ; 
the above. During a walk up the Cliff-road, Mr. Sanders 
gave a brief explanation of the geological features of tbe 
cliffs. He said that the various theories put forth to account 
for these great fissures might be divided into two classes. 
The first and most probable supposed that the fracture had 
Icommenced during tbe upheaval of the rocks from below, 
' for, consisting of carboniferous limestone themselves, they 
! had been ander water during the whole time of the deposit 
tion of the New Red Sandstone. If a gradual elevation, 
such as is now going on in Sweden, took place during this 
period, any crack ©r fissure would be enlarged by the action 
of the waves, and thus a large chasm formed, if suflicient 
time were allowed. The other theory had been put forth by 
Professor J. B. Jakes, and supported by Professor Ramsay, 
and attributed these chasms— of which the valley of the 
Avon was another example— to the slow action of little rills 
of fresh water, wearing down the valley, after the whole of 
the rocks had been upheaved from the sea^bottom. Mr. 
Sanders then adverted to the total absence in this ravine of 
such evidences of glaciers as were seen in Snowdonia 
and Cumberland, and said he was disposed t«> infer 
ithat durmg the Glacial epoch there were no glaciers 
I in the South of England. Oa returning to the Inn, 
several interesting plants were met with, including 
the yellow poppy or Meconopsis Cambrica, Polypodium 
icalcareum, &c. Dinner was served in the girden of the 
inn, after which Mr, Cox took the party in detachments to 
see the interior of the famous caverns, which, by the kind- 
ness of Mr. Stoddart, were illuminated with the magnesium 
light. The effect of this was very wonderful, the stalactites 
standing out with marvellous distinctness, and the rich 
drapery of the roof being visible over a large extent of sur- 
face, leaving an impression which will not soon be forgotten, 
an4 which imagination can scarcely picture. The setting 
sun, however, warned the members that the pleasantest days 
must end, and f^iey therefore returned to Bristol by way of 
Axbridge, Cross, Redhill, and Barrow, after a most inter- 
esting and delightful excursion, the enjoyment of which was 
heightened by the great clearness and mildness of the atmos- 
phere. 
Sectioxatj Meetings— Botanical Section, Aug. 8th. 
— Several members of the section took advantage of ibe 
Fairy Queen to explore the neighbourhood of Portishead. 
The evening was fine, but tbe time allowed very limited. 
Under tbe battery point tbe underwood yielded Galeopsis 
Tetrahit, Vicia cracca, and Hypericum perforatum. The 
land skirting the sea shore had several specimens of Ery- 
tbjGi cantaurium, whose pretty rose-coloured flowers were 
closed, except in sunshine, Eupatorium cannabinum, and 
Tencrium Scorodonia. On the marshy ground AltbjBi 
officinalis, or marsh mallow, was met with, and near 
the rhines Alisma plantago, Myosotis ccespitosa, RanunculuH 
Flaminula and R. Sceleratus, Samolus valerandi, andHeloa- 
ciadium nodiflorum, often mistaken for watercresses. Some 
interesting microscopic plants and animals were also cap- 
tured in the rhines. 
