Effects of Earthquake Waves on the Coasts of the Pacific. 181 
more convenient in practice. The only theoretical reason 
for commencing at high temperatures would be to include 
both the hardening and the polarizing degrees in the same 
process; but it appears doubtful whether these are so con- 
nected as to give any advantage in practice, however advan- 
tageous it may be to commence the process above the depo- 
larizing temperature. 
Royal Institution, Jan. 27, 1836. 
XXXIII. On the Effects of the Earthquake Waves on the 
Coasts of the Pacific. By WoovstnE Panisu, Esq., F.2.S., 
Secretary to the Geological Society.* 
T one of our meetings last season, in a discussion which 
arose out of the discovery of recent shells and other ma- 
rine deposits on several parts of the coasts of Chile and Peru 
above the present level of the sea, I ventured to throw out the 
opinion that a great part of those appearances might, perhaps, 
be referred to violent upheavings of the sea under the influence 
of earthquakes. I had then only in my recollection the earth- 
quake waves which burst over Scylla and Lisbon in Europe, 
and Callao in America; but upon looking into the early 
writers upon the countries bordering on the Pacific, I have 
found so many recorded instances of these disruptions of the 
great ocean, and in some cases attended with such remarkable 
effects, that I have thought it might interest the Society to 
have them collectively before it, particularly upon any new 
discussion of such phenomena as first gave rise to my obser- 
vations upon the subject. 
Under that impression I have put them together in this 
paper. 
Historical Notices of the Effects of the Earthquake Waves on 
the Coasts of Chile and Peru. 
Acosta in his Historia Natural y Moral de las Indias, writ- 
ten in 1590, gives us a chapter upon the earthquakes of his 
time, from which the following is a translation: he says, ** On 
the coast of Chile, do not remember precisely the year, 
there took place a very terrible earthquake, which overthrew 
whole mountains, stopping up with them the courses of rivers 
and turning them into lakes, destroying towns, and a vast 
number of people.” Jt caused the sea to rise out of its bed 
some leagues, leaving ships dry far inland. 
* Read before the Geological Society Dec, 2, 1835 ; and now communi- 
cated by the Author. 
