60 REPORT—1843. 
a practical and personal evidence of which he experienced in the harbour of Trave- 
munde, on the 4th of May, by the sudden fall of water at the port, which took place 
very rapidly and to a great extent. The steamer, which ought to have left Trave- 
mund on the 18th, was detained by this cause until the 21st. It is well known, that 
althongh without tide, the Baltic is subject to periodical variations of depth, but the 
water has fallen during the present summer to a degree far below these ordinary 
variations : and the fact was considered so remarkable, as to be thought worthy of 
being brought before the notice of the Swedish Academy of Sciences, by Baron Ber- 
zelius, in July last. This fall or diminution of water was already perceptible in the 
summer of 1842, since which the Baltic has never returned to its average mean 
height; but, on the contrary, has diminished, and there seems now no probability 
that the former level, or the height of 1841, will be again attained. Meantime, no 
perceptible change has taken place in the waters of the North Sea, and the unscien- 
tific observer asks, what has become of the waters of the Baltic? The answer is 
probably to be found in a simultaneous phenomenon apparent on the Swedish coast, 
the gradual elevation of which has been satisfactorily proved by the personal obser- 
vation of Mr. Lyell. Recent observation, however, would seem to show, that this 
elevation does not proceed at any regular or fixed rate, but, if he might use the ex- 
pression, jitfully, at uncertain periods, and at a rate far greater than was at first sup- 
posed. At the same meeting, when Baron Berzelius drew the attention of the 
Swedish Academy to the diminution of water in the Baltic, a communication was 
made from an officer who had been employed on the south-west coast of Sweden, in 
the Skargard of Bohuslan, north of Gottenburg, giving evidence of the recent eleva- 
tion of that part of the coast, and stating, that during the present summer fishermen 
had pointed out to him, near the Malostrom, at Oroust, shoals which had never before 
been visible. The elevation of the Swedish coast forms a striking contrast with the 
unchanged position of the contiguous coast of Norway, which, as far as observation 
has been hitherto extended, has suffered no change within the period of history, al- 
though marine deposits, found upon the Norwegian hills, at very considerable eleva- 
tions above the level of the sea, prove that those parts were formerly submerged. 
More accurate information, however, will, before long, be obtained on this interesting 
point, as a commission has been appointed by the Norwegian government to investi- 
gate the subject, and marks have been set up on the coast which will, in a few years, 
afford the desired information. Meantime, the Scandinavian peninsula presents an 
extraordinary phenomenon ; the western, or Norwegian side, remaining stationary, 
while the south and east, or Swedish sides, are rising, and that, as the author had 
endeavoured to show, at no inconsiderable rate. 

On certain Movements in the Parts of Stratified Rocks. 
By Prof. J, Purtures, F.R.S. 
The author stated that for many years the attention of geologists had been called 
in avery essential degree to the internal structure of rocks ; but notwithstanding the 
advances made by Prof. Sedgwick and Mr. Hopkins, there were points still remain - 
ing to be investigated, before mathematicians could explain the forces by which these 
phenomena had been produced; because any such explanation must be based upon 
data afforded by the actual constitution of the rocks themselves. Twenty years since 
he had observed such remarkable symmetry in the crystalline forms of prismatic 
masses of slate in Westmoreland, that he had measured their planes, and satisfied 
himself that they were not of the nature of ordinary crystallization, and that the term, 
crystalline structure, as usually applied to them, was by no means legitimate. In 
order to understand the nature of the mechanical forces which have produced the 
cleavage, it is important to study it in its relation to every form of strata. Con- 
tortions which do not affect the cleavage planes, were evidently formed before 
them ; the joints and fissures which interrupt the cleavage but do not disarrange it, 
were probably posterior, like many of the faults which interrupt the strata and cut 
off the cleavage. When layers of concretionary ironstone occur in slaty rocks, the 
cleavage planes are arrested and “troubled” in their passage through them, from 
which it appears that the nodules had become solid previously to the strata being di- 
