a =. 
pea Gl fre Se 
ee owed 
Rips 
TRANSACTIONS OF THE SECTIONS. 59 
three and a half miles per minute in the case of the New England earthquake of 1756; 
and at the rate of five miles per minute during the great Lisbon earthquake, the waves 
succeeding each other at regular intervals of five minutes. Assuming these sea-waves 
to correspond with the undulations beneath, the authors calculate the breadth of the 
crust-waves in the Lisbon earthquake at twenty-five miles; and in the earthquake of 
Conception, where the undulations averaged four per minute, and travelled forward 
at the rate of forty-two miles in the same time, each wave possessed a breadth of at 
least ten geographical miles. The tremor attending earthquakes is considered as the 
effect of the crushing of the strata during, and caused by, the undulations, rather than 
as the result of waves of vibration, which would be dispersed and destroyed by the 
broken condition of the materials and their heterogeneous composition. 
Application of the theory of earthquakes.—From these considerations the authors 
infer, that when earthquakes produce any permanent elevation or depression of the 
land, the tracts so affected will generally have the shape of elongated parallel belts, 
as exemplified in the Ullah Bund in the Delta of the Indus, the elevation of the coast 
of Chili, and the local arching of the surface across the bed of a river in Chili, men- 
tioned by Darwin. Referring to their memoir on the Appalachian chain, the authors 
contend that the structure of those mountains (and, by analogy, those of other coun- 
tries) implies the operation of far greater and more sudden forces than the gentle 
secular changes observed in modern times; and they consider it impossible to avoid 
the conclusion, that all the more extensive revolutions of the earth’s crust have in- 
yolyed, to a greater or less extent, the agency of vast earthquake waves. To the action 
of these waves, in different geological epochs, they attribute the formation of the vast 
masses of conglomerate and detrital deposits distributed in the various groups of 
strata; also the transport of the great northern drift, and the polished and furrowed 
surfaces of rocks both in Europe and New England. 
An Account of the late Earthquake at the Islands of Antigua and Guadaloupe, 
on the 8th of February 1843, By the Hon. Capt. Carnecte. 
The earthquake is described by the author of the communication as having been 
telt, generally, among the Leeward Islands, but more particularly at Antigua and Gua- 
daloupe. At both these islands the shock took place at twenty minutes before eleven 
o’clock, a.M., and it does not appear to have been preceded by any of the usual signs 
of earthquake; the weather was clear and fine, the sea-breeze blowing as usual, and 
the inhabitants engaged in their daily avocations. At Antigua the earth heaved and 
undulated suddenly ; the hills oscillated, and huge masses of rock were detached from 
their summits and precipitated into the valleys; large fissures opened in the ground 
and closed immediately. The water in the harbour whirled round and round, enve- 
loping the islands in a cloud of dust, which shut them from view, and in the space 
of two minutes and a half all Antigua was laid in ruins. In this island only eight 
persons lost their lives, owing to the black population being employed, as usual, among 
the canes, but the loss of property was immense. At Point-a-Pitre, in the island of 
Guadaloupe, the effects were much more fearful. In magnitude, this was the second 
town in the West India islands; it was situated upon a piece of low ground, sur- 
rounded on three sides by the sea, and entirely built of stone to avoid the effect of 
hurricanes. At the time of the earthquake, most of the inhabitants appear to have 
been at their late breakfast, in consequence of which 4000 perished among the fall- 
ing houses or in the fire which broke out immediately after; the destruction of the 
whole town was so complete, as to present, after the earthquake, the appearance of 
a vast stone quarry. The Jandslips were very numerous, and all the springs in the 
vicinity of Point-a-Pitre were instantly dried up. The shock was felt slightly as far 
north as Washington and Bermuda, and southward to Demerara, travelling in a 
N.N.E. and S.S.E. direction ; several slight shocks were subsequently felt at differ- 
ent periods. 
On the apparent fall or diminution of Water in the Baltic, and elevation of the 
Scandinavian Coast. By Major N. L. Bzamisu, F.R.S. 
During a journey to Stockholm in the early part of the present summer, the author 
had occasion to see and hear much respecting the diminution of water in the Baltic, 
