ON THE FACTS OF EARTHQUAKE PHENOMENA. 75 
year 1687, for a long time prevented the success of certain crops. There 
have also been strange colourings of the heavens and unusual fogs noticed 
as occurring at the same time with earthquakes; such as the unusual colour 
of the sky at Lisbon on the 1st of November 1755, and the dry fog (Webel), 
which was so thick as to produce darkness, during the earthquake in Cala- 
bria in 1783. Since observations upon phenomena of this kind, made in 
modern times, deserve more confidence than those which are preserved in 
the older accounts, I do not consider it altogether superfluous to quote some 
instances in modern times of remarkable conditions of the atmosphere existing 
during earthquakes :— 
“1824, 12th August.—In Tuscany. The sun appeared as it were veiled, and 
was more like the moon. 
1824, 30th November.—In Martinique. After the earthquake, the tempe- 
rature of the air (which before had been very high) fell very con- 
siderably. 
“ 1895, 19th January.—At St. Maura. Extremely heavy showers succeeded 
the earthquake, and lasted for several days. 
“1826, 23rd November.—lIn the Tyrol. The violent wind which had existed 
before the earthquake, ceased during its continuance, and rose again 
after its termination. 
“ 1827, 1st February—In Naples. On the day of the earthquake; the air; 
which before had been very cold, suddenly became pleasantly warm. 
“1827, 3rd June—In Martinique. Rain immediately succeeded the earth- 
quake, although none had fallen for sixty-six days before. 
“ 1828.In Peru. The most unusual and extremely violent rain, lasting four 
days, succeeded the earthquake in the district which had been most 
severely visited by it, namely at Truxillo, Lambeyeque, Chiclaya, Puira; 
and in the desert of Sechua. 
“ 1830, 8th February—AtAgram. A fog, having a very bad smell; spread 
itself Abroad, and lasted for three hours. 
“1831, 3rd December.—At Martinique. Heavy showers of rain fell after. 
the earthquake. 
“1892, 18th October—In Saxony. After the earthquake, the thick yellow 
fog; which had existed there for several days, suddenly dissipated itself, 
and the air; which before had been harsh; became mild. 
« 1834, 4th Octoberi—At Bologna. After the earthquake, the air became 
suddenly cold. 
1835, 27th October.—In the Pyrenees. During the earthquake there rose 
clouds of hot air, which gave out a distinct smell of sulphur.” (Von 
Hoff, Gesch. Veran: Erdober; Th. iv.) 
Further observations on-this whole branch of our subject are imperatively 
called for: Meanwhile we have provisionally concluded, with great proba- 
bility, that earthquakes occur in all times, seasons and weathers, and have no 
very immediate relation with meteorology; in the epochs just before and 
during their occurrence: 
But it is a very different question how far their occurrence or frequency 
may be influenced;—lIst, by the climate; and 2nd; by the meteorological 
conditions prevailing in a given large district for a considerable time before 
their occurrence; and again; a totally different inquiry is, what are the im- 
mediate and remote reactions of earthquakes upon the climate and meteoro- 
logy of the country affected. 
. It cannot be too often insisted on that earthquakes are not motive agents 
of elevation and depression on the globe, for we find this confusion perpe- 
tually, even in the highest authorities, such as Sir Charles Lyell, who fre- 
