140 Miscellaneous Intelligence. 
fifteen cubic feet, or about one ton in weight, and thrown on the beach, 
after having been built into the wall; and a stone containing 18 cubic 
feet was moved 30 feet from its place ; while the peeres perdues or 
mound stones were washed down to a slope of about 4 to 
~ The following instance, which occurred at the seit slip of the 
Calf Point, Isle of Man, affords a proof of the great force of the waves 
even in the Irish Sea. During a gale from the northwest, a block was 
lifted from its place in the wall and thrown landwards, which measured 
1234 cubic feet, equal to about 10 tons weight. 
In the German Ocean, we can refer to the Bell Rock Lighthouse, 
which, though 112 feet in height, is literally buried in foam and spray ~ 
to the very 1op, during ground swells, when there is no wind. It is, 
therefore, a very important station for making such experiments, be- 
cause the rise of the spray may be regarded as a scale by which the 
results of the Marine Dynamometer can be checked or compared. 
In the published account of this work there occurs the following 
statement :—On the 24th October, 1819, the spray rose to the height of 
105 feet above the rock. ‘It may, perhaps, therefore,” says the au- 
thor, “be concluded, that the maximum force of the sea at the Bell 
Rock is to raise the sprays to the height of about 105 feet above the. 
surface of the rock ;” and deducting 16 feet, which is the height that 
the tide rises upon the tower, there is left 89 feet, as the height to which 
the water is raised. This is equivalent to a hydrostatic pressure of 
about 24 tons on the square foot. Since that time, however, there have 
been still greater proofs of the force of elevation. On the 20th No- 
vember, 1827, the spray rose 117 feet above the foundations or low 
water mark; and the tide on that day rose 11 feet upon the tower, 
leaving 106 feet as the height of elevation, (exclusive of the trough of 
the sea,) being equivalent toa preeiare of very nearly 3 tons per square 
oot. 
At the island called Barrahead, one of the Hebrides, a remarkable 
example occurred during a storm in January, 1836, in the movement 
of a block of stone, which, from measurements taken on the spot, is 
9 feet X 8 feet X 7 feet = 504 cubic feet, which, allowing 12 feet of 
this gneiss rock to the ton, will be about 42 tons weight. This great 
mass was gradually moved 5 feet from the place where it lay, having 
been rocked to and fro by the waves till a piece broke off, which rolling 
down, and jamming itself between the moving mass “and the shelving 
rock on which it rested, immediately stopped the oscillatory motion, 
and thus prevented the farther advance of the stone 
Mr. Reid, the principal keeper of Barrahead Hghthouée; the wine of 
4 nesses 
a hy eS. 
