a ae 
<9 *s 
and Extraordinary Movements of the Sea. 277 
that “‘ the mereury was precisely at its minimum height at the 
moment of the third and last shock.”’* On the 10th of No- 
vember 1782, when Loch Rannoch was violently agitated, the 
barometer in Scotland sunk to within one-tenth of the bottom 
of the scale (probably 27.1 inches.) During the extraordi- 
nary depression of the barometer throughout Europe on the 
25th of December 1821, a slight shock of an earthquake was 
felt at Mayence.t 
Mr Milne has collected eighteen instances during the 
last hundred years, to prove the connection between great 
disturbances of the atmosphere and extraordinary oscillations 
of the sea. I have endeavoured to prove that the interme- 
diate links of this connection are submarine shocks. I now 
proceed to shew that such disturbances in the air, earth, and 
sea, are probably often occasioned by the action of the moon. 
I cannot better introduce the subject than by the following 
passage from Humboldt. “On the 5th November 1799, 
exactly at the same hour as the preceding day (when the 
earthquake already noticed took place during a severe thun- 
der-storm) there was (on the 4th) a violent gust of wind at- 
tended by thunder and a few drops of rain. No shock was 
felt. The wind and storm returned for five or six days, at 
the same hour, almost at the same minute. The inhabitants 
of Cumana, and of many other places between the tropics, 
have long ago made the observation, that those atmospheri- 
eal changes which appear the most accidental, follow, for 
whole weeks, a certain type with astonishing regularity. The 
same phenomenon exists in summer under the temperate 
zone ; nor has it escaped the sagacity of astronomers, who often 
see clouds form in a serene sky, during three or four days 
together, at the same part of the firmament, take the same 
direction, and dissolve at the same height,—sometimes be- 
fore, sometimes after, the passage of a star over the meri- 
dian ; consequently within a few minutes of the same point 
of apparent time. M. Arago and I paid great attention to 
* Personal Narrative, vol. iii. p. 319. 
+ Jameson’s Edinburgh Phil. Journal, Oct. 1841, pp. 295, 296. 
