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subject, he stated some of the principal conclusions that the 
discussion of the facts by the method of curves warranted. 
The records of earthquakes become more and more nume- 
rous as navigation and travel have, in the course of time, be- 
come extended, though it is not probable that the actual 
number of earthquakes occurring at a remote antiquity was 
less than now. 
Their extreme frequency, during the last two or three cen- 
turies, since the attention of mankind has been alive to the 
record of such phenomena, and intercourse has been more per- 
fect, is such as fully to warrant the position of the author’s 
first Report, that no day passes without one or more; and 
that they are the indices of a constantly and pretty uniformly 
present, cosmical force; ‘‘the re-action of the interior of the 
planet upon its exterior” having, however, epochs of greater 
disturbance and epochs of repose. 
The peculiar features of the curves exhibited to the Aca- 
demy were shown, and of the secondary deduced curves of 
maxima, &¢c., as also the deduced curves, showing the dis- 
tribution of earthquakes with reference to seasons and months. 
These seem to indicate a preponderance in the winter months ; 
but the author is disposed to view this result as accidental, 
although agreeing with the deduction of M. Perrey from his 
much more limited base of induction. 
The author also exhibited and explained his large Chart of 
the World, on Mercator’s projection, on which the distribu- 
tion of earthquakes in space is laid down from the Catalogue, 
and, by a peculiar system of colouring, the relative intensity 
and area of disturbance, and the number or reduplication of 
shocks also indicated, for every locality over the whole explored 
surface of the earth. 
He pointed out the results which this map indicated, and 
the differences between it and the maps of Johnston and 
Berghaus. 
The largest habitually convulsed area now on the earth’s 
