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ON THE FACTS AND THEORY OF EARTHQUAKE PHENOMENA. 33 
meridian, the plane of which passes through the centre of the moon. With- 
out entering into longer details, we can easily conceive that, if the fusion of 
the interior mass of the globe plays a part among the causes of earthquakes, 
then its influence may become evident by a necessary connexion, capable of 
observation, between the occurrence of earthquakes and the circumstances 
which modify the moon’s action upon the entire globe, or upon a portion of 
it, namely, its angular distance from the sun, its real distance from the earth, 
and its angular distance from the meridian of the place, or, in other words, 
the moon’s age, the time of perihelion, and the hour of the lunar day. 
“These considerations, which occurred to M. A. Perrey, doubtless in- 
spired him with the idea of the two works which we have been commis- 
sioned to examine, at the same time that they assisted in attracting the 
interest of M. Arago and many other learned men to the results which he 
obtained ; but they also suggest that the essential object of the inquiries on 
which we are commissioned to report ought to be, to ascertain the precise 
date, according to the lunar day and month, of every earthquake the 
record of which history has preserved, and even of each of the shocks 
of which these earthquakes consisted. We can easily imagine the immense 
toil which such a research would demand, and understand that M. Alexis 
Perrey having already devoted several years to it without bringing it toa 
termination, has yet been enabled at different intervals to obtain such par- 
tial results as M. Arago deemed worthy of the encouragement and attention 
of the Academy ; and that the learned Professor at Dijon is impatient, before 
encountering the labours of still more years, to learn whether the Academy 
approves of the course which he has hitherto pursued. The necessity the 
author feels for the support and direction of the Academy explains why he 
has, upon several occasions, submitted to it results which naturally could 
not be complete, and which are not entirely so even in the paper and note 
which we are commissioned to examine. In the paper presented on the 
2ist March 1853, ‘On the Connexion which may exist between the occur- 
rence of Earthquakes and the Moon’s Age,’ the author has devoted the first 
chapter to the calculation and numerical changes of the rough results of 
observation. 
“ He has supposed four possible methods of calculation. In the first, 
already followed in the memoir presented to the Academy May 5, 1847, 
the author considers as a day of an earthquake each day upon which a 
shock has been felt, whether in a single country, or in two or more coun- 
tries at the same or at different hours, separated from each other by spaces 
in which the motion was not experienced. Then noting, according to the 
knowledge of the period, to which day of lunation each day of earthquake 
corresponded, he arranges all the days which belong to the first day of 
lunation, then all those which correspond to the second day, the third, the 
fourth, &c.; and he constructs a table composed of thirty lines, each line 
indicating the number of earthquakes which belong to the corresponding day 
of lunation. Now these numbers vary one day with another, and they vary 
nearly in accordance with the same law, both in a table comprising a total 
of 2735 days of earthquake, the result of researches carried on during the 
years from 1801 to 1845, drawn up by the author and presented to the 
Academy May 5th, 1847; and in a new table containing a total of 5388 
days of earthquake, embracing the result of extensive researches carried on 
from 1801 to 1850. 
“Tn both tables the number of earthquakes corresponding to the days 
close to the Syzygies, is generally a little more considerable than that which 
Pe sponds with the days close to the Quadratures. In the second method 
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