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, ON THE FACTS OF EARTHQUAKE PHENOMENA. 67 
the ai of weather or appearance of air and sky immediately before earth- 
quakes. 
In the south of Europe a general belief prevailed that calms, oppressive 
heats and a misty atmosphere, were the usual preludes of earthquake. Ha- 
milton says he found it a_general observation in Calabria, “that before a 
sheck the clouds seemed to be fixed and motionless, and that immediately 
after a heavy shower of rain (during the earthquake), a shock quickly fol- 
lowed.” And in the Philippine Islands, De Guignes informs us that “a calm, 
the sky gray and cloudy, the atmosphere heated and heavy, occasional gusts 
of wind, and at intervals gentle showers of rain, are the prognostics by which 
earthquakes are anticipated there.” After recording a number-of vague 
opinions held by the South Americans, as to the weather prognostics of 
earthquakes, Humboldt says, “ These are however very uncertain, and when 
the whole of the meteorological variations at the times when the globe has 
been most agitated are called to mind, it is found that violent shocks take 
place equally in dry and in wet weather, when the coolest winds blow, or 
during a dead and suffocating calm.” (Humboldt, Per. Nar. vol. ii. p. 223.) 
Again, the veteran philosopher says that “ even in Italy this belief is dying 
away ;” and expresses his own conviction, strengthened by that of those who 
have lived long in the great shaken countries of South America, that earth- 
quakes are independent of the weather or appearance of the heavens imme- 
diately before the shock. He says he has felt earthquakes when the air was 
_ clear and a fresh ‘east wind blowing, and also when there was rain and 
_ thunder-storms; and this has been very recently confirmed by the continuous 
observations made at New Zealand during the earthquake of 1848, which 
began in a gale of wind. 
On the relation of earthquakes and volcanic eruptions generally to the 
condition and phenomena of the atmosphere, Von Hoff remarks; ‘“ The 
question, whether any relation or causal connexion exists between the various 
movements of the earth and those occurring in the atmosphere, has for a 
long time remained unanswered. The intimate connexion which subsists 
between the earth and its atmosphere, and which manifests itself in so many 
_ phenomena, has always induced people to presuppose a similar connexion 
_ between earthquakes and volcanic eruptions, and the condition of the atmo- 
_ sphere. They believed that the influence of the latter might be engaged in the 
_ voleanic process, and that, on the other hand, earthquakes and yolcanie¢ erup- 
tions might produce some effect on the condition of the atmosphere. The 
_ proof of the first of these opinions, it has been thought, was to be found in 
great falls of the barometer, in remarkable calms, in dry mists, and unusual 
_ gtay or red colouring of the sky, and especially in great heat. 
* Amongst the effects supposed to be produced by the earthquake on the 
atmosphere, were reckoned tempestuous winds, thunder-storms, meteors, cold- 
_ ness of the air, severe winters, heavy rain, miasmata, producing diseases and 
“affecting vegetation. A very remarkable instance of the latter is quoted, 
_ namely, that in Peru; after the earthquake of 1687, wheat and barley would 
= thrive at all, though formerly the country was remarkably favourable for 
em. 
; “ There can be no doubt that an answer to the question, whether a con- 
hexion exists between these phzenomena of fixed terrestrial bodies and the 
‘condition of the atmosphere, is of the greatest importance to a thorough 
“knowledge of both. But from the multifarious conditions which have here 
_ to be taken into consideration, from their complication, and from the diffi- 
culty of distinguishing, amongst many recurring at the same time, between 
‘the indifferent and those which are really important, an extended series of 
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