186 Prof. Powell on the Transmission of Radiant Heat. 
try of the dreadful earthquake which, on the 20th of February 
last, again utterly destroyed the city of Conception, with its 
sea-port at Talcahuano, and all the towns of Chile between 
the parallels of 35° and 38° south latitude. 
The details which have as yet reached us afford another 
remarkable evidence of the direful and irresistible effects of 
the earthquake wave. In the Bay of Talcahuano the sea is 
said to have risen three times, overwhelming the town, and 
sweeping away its ruins with such a rush and whirl of waters 
as, to quote one account, it is more easy to imagine than 
describe, and carrying some of the ships far up upon the 
shore. 
The circumstance of a vessel, ‘the Glemalier,” having ex- 
perienced a violent shock when at a distance of ninety-five 
miles from the coast, which stopped her course and induced 
the master to believe she had struck the ground, coincides 
remarkably with old Wafer’s account of what happened to 
himself off the coast of Peru during the earthquake of 1687, 
and is of value, in as much as it corroborates his testimony to 
a fact which before seemed hardly credible*. 
Such is the list with which history furnishes us of these 
terrific inundations. Fearful as it is, if we bear in mind how 
recently we have become aware even of the existence of those 
coasts, and how extremely imperfect is our knowledge of 
them at all, we shall have no difficulty in believing that it 
comprises but a very small portion, indeed, ofa series of events 
which, in a very short period of time, geologically speaking, 
must have left indelible marks of their tremendous agency, 
attesting but too well the calamitous visitations to which the 
inhabitants of those shores are subject. 
XXXIV. Note on the Transmission of Radiant Heat. By the 
Rev. BavEN Powet1, M.A., F.R.S., Savilian Professor of 
Geometry, Oxford.t 
FEW scientific discussions are more unsatisfactory than 
those in which writers endeavour to point out, or explain, 
misconceptions of each other’s meaning. In reference to one 
or two remarks somewhat of this nature made in the course 
of papers in recent Numbers of this Journal, on the subject of 
radiant heat, I will merely state, in the fewest possible words, 
* We believe that several if not many other instances of the same fact 
have been recorded, chiefly in the older accounts and collections respect- 
ing earthquakes.—Eprr. 
+ Communicated by the Author. 
