ON THE FACTS AND THEORY OF EARTHQUAKE PHENOMENA. 39 
herein I find the explanation of certain leaps of astronomical clocks of which 
the learned have not hitherto been able to discern the cause. I believe 
that one day we shall have the equation of time in functions of the varia- 
tions of intensity of the planetary attractions, and of the regular oscillatory 
movements of the earth, as we now have the equation of time in functions 
of the motions of translation and of rotation of the earth itself. I say the 
regular oscillatory motions, because, as for the irregular movements, we 
cannot submit them to rule, and we are enabled to account only for the 
extraordinary concomitant phenomena presented by the atmosphere, by the 
earth, and by certain species of animals. The irregular motions which we 
call earthquakes, happen more frequently, it has been observed, either at 
the epoch of the Syzygies rather thanat the epoch of the Quadratures, or 
oftener at the epoch of spring tides than at that of the neaps. This important 
observation is found in the works of Georges Baglivi and Joseph Toaldo. 
The first, in his ‘ Storia Romani Terre Motus, anni 1703,’ says, “In 
singulis lune aspectibus, seu quadraturis, potissimum in plenitudine ejusdem 
seu totali oppositione cum sole, certo succedebant terres motus, frequenter 
paululum praecedebant ipsos aspectus.”—Georgii Baglivi Opera Omnia, 
Bassani, 1737, p. 415, Editionis Venetiarum, 1752, p. 326. 
Toaldo, speaking generally of earthquakes, says, ‘“ the late M. Bouguer 
in the account of his voyage to Peru speaks much of earthquakes, so fre- 
quent in that country. He mentions with doubt the assertion of a Peru- 
vian ‘savant,’ that earthquakes have certain fatal and marked lines when 
they occur at low water. On the other hand, Chauvalon, in his voyage to 
Martinique, notes particularly the earthquakes which took place at the 
time of high water; and the earthquake which destroyed Lima on the 28th 
of October, 1746, occurred at three o’clock in the morning, at the instant of 
high water (ora della prima acqua). Thus we remark in other countries 
that these phenomena may themselves depend on the cosmical causes of the 
action of the sun, and especially of the moon.” (Giuseppe Toaldo, ‘ Della 
Vera Influenza degli Astri, etc., Saggio Meteorologico,’ Padova, 1770, 
p- 190.) I hope that the Academy of Sciences will well receive these do- 
cuments and these ideas, which tend to augment the merit and the value 
of the very important studies of M. Perrey. 
Edmonds, also, has endeavoured to show that many formidable earth- 
quakes are found to have occurred the day after the moon is in her first 
quarter (‘ Journ. Polytec. Soc. Cornwall, Note 158 ; Sabine’s ‘ Cosmos’). 
Before dismissing the subject of other earthquake catalogues, the follow- 
ing labour as to Indian earthquakes should be noticed. In the ‘Journal of 
the Royal Asiatic Society,’ vol. xii. n.s., for 1843, Lieut. R. Baird Smith, 
5.E., made one of the most extensive contributions to our slender stock of 
oriental earthquake annals. He divides India into nine earthquake tracts, 
partly on physical grounds, partly arbitrarily, viz.— 
1. Central Himalaya; 
2. Lateral Himalaya, including— 
“ a. Cabul, 
. b. Jellallabad, 
F e. Cashmere, 
' d. Nepaul, 
i e. Assam ; 
3. The Solymaun Mountains, 
aereE 4. The Aravulli Mountains, 
