1851.] OF THE ROYAL INSTITUTION. 51 
tends below it. In those impressions which have been made when the 
wind was blowing, and when the rain fell obliquely, the cavities are 
not only of an oval shape, but all deeper at one end than at the other. 
Foot-prints of birds, and the winding tubular tracks of annelids are 
seen on the same surface with the rain-prints. On splitting open 
slabs formed by numerous thin layers deposited by successive tides, 
impressions of previous showers are seen, and casts of the same, 
standing out in relief on the under surface of incumbent layers. 
The Lecturer next considered the nature of certain small protube- 
rances, which might, on a cursory view, be mistaken for casts, which 
project from the upper surface of certain layers of mud, and are 
caused, some of them by dried bubbles of mud, and others by small 
particles of solid matter, covered with a film of mud. He also dis- 
tinguished between the cavities produced by air-bubbles rising up 
through the mud, which give rise to cavities differing in shape from 
those formed by rain, as he has proved by several experiments. 
In illustration of the foot-tracks of quadrupeds, such as the musk- 
rat, the minc, the dog and others, so common on the recent red sand 
of Kentville, on the borders of the Bay of Fundy in Nova Scotia, Sir 
C, Lyell exhibited a copy of a brick, one foot square from Babylon, 
now in the British Museum, on which the track of a small animal of 
the Ichneumon tribe, apparently the Asiatic Mongoose, is distinctly 
seen. This brick has been sun-dried (not baked in a kiln,) and must 
have been traversed by the creature, when the clay mixed with straw 
was still very soft. In the middle of the brick is an inscription in the 
Babylonian cuneiform character, which according to Colonel Raw- 
linson’s interpretation signifies that Nabokodrossor, King of Babylon, 
built certain cities, &c. This king is the same as the Nebuchad- 
nezzar of scripture, so that the brick is twenty-four centuries old. 
When the tidal waters densely charged with fine sediment creep 
gently over a slightly inclined sand or mud-bank, they do not 
disturb the surface, especially when it has been baked hard in the 
sun, as happens in summer in Nova Scotia; and the new layer of 
matter which is thrown down, fills up all superficial indentations, 
which serving as moulds are protected from further disturbance by 
the casts thus taken from them. 
Mr. Cunningham threw out as a conjecture, that the fine-grained 
quartzose substance of Storeton Hill, might have resulted from 
blown sand. That such was really its origin, Sir C. Lyell, who has 
himself examined the quarries on the Mersey, entertains little doubt ; 
for on the sea-shore near Savannah in Georgia, he saw the foot- 
tracks of raccoons and opossums which had been made in sandy mud 
at low water, in the course of being gradually filled up with blown 
sand, clouds of which were swept along by the wind frora adjoining 
cliffs. This layer of sand when the tide rose again would in its turn 
be overspread by a new deposit of mud. 
After describing both the impressions and casts of rain occurring 
in the recent red mud of the Bay of Fundy, the Lecturer pointed 
