᾿ 
i ON THE FACTS OF BARTHQUAKE PHENOMENA. 41 
upon the coast between towns at either side which suffered much, no shock 
at all was felt. These differences, says Humboldt, in the direction and pro- 
pagation of the shock are probably owing to the peculiar arrangement of 
the stony strata. (Per. Nar. vol. iv. p. 19.) 
Again, it is manifest that in estimating the demolishing effects of any 
shock upon buildings, very much depends upon the direction in which the 
shock acts upon the building with reference to its particular form and struc- 
ture, and as this was not sufficiently known or attended to by former ob- 
servers, fresh information remains to be collected by competent persons as 
to this part of our subject. , 
This concludes the first branch of our subject, viz. all that relates directly 
to the earth-wave or shock ; and we now proceed to the sound-waves, which 
are more or less connected with it. 
93rd. Earthquakes occur which are accompanied by various 
sounds, having a subterraneous origin, and which may either 
precede, or accompany, or succeed, the occurrence of shocks, 
or precede, accompany, AND succeed, the shocks of some of 
them; and again, earthquakes occur, even of the greatest 
violence, unaccompanied by any sound whatever. 
The intensity of the sound is by no means in proportion to the violence of 
the earthquake. One of the most tremendous earthquakes on record, that of 
Riobamba, occurred, according to Humboldt, unaccompanied with any 
_ noise whatever. 
The kind of sound has been very variously described, so variously as to 
induce the belief that there are different sounds on different occasions. 
_ Humboldt says (‘Cosmos’), “ It is either rolling, or rustling, or clanking, like 
chains being moved, or like near thunder, or clear and ringing as if obsidian 
_ or some other vitrified masses were struck in subterraneous cavities.” One 
 tannot but imagine that in the latter similitude the ear has borrowed its 
impression from the preconceived view of the author’s mind. 
_ Professor Krashenikoff, of St. Petersburg, in his description of Kamschatka, 
as translated by Dumaresque (1760), says, Earthquakes happen here several 
times in the year. The most violent that was observed, was in the beginning 
of February 1759, which, during a westerly wind, lasted exactly six minutes ; 
and before it a noise was heard and a strong wind under ground, with a hissing 
which went from north to south.” By some the sound has been directly 
compared to that of quenching a mass of red-hot iron in water. There was 
_ashock of earthquake at Coningsby in Lincolnshire, in England, on the 6th 
_ of February 1817, and also at Holderness near it, when it was heard “ like 
_ Waggons running away upon a road; and so forcible was the illusion, that 
_ Waggoners on the roads actually drew up their teams to let the supposed 
_ runaway waggon pass them safely. While this was heard at Coningsby, they 
_ heard also at intervals of about a second of time, sharp and loud noises like 
the discharges of gunshots; and all gradually died away to a grumbling noise, 
_which shifted from the east to the south.” (Quart. Journal, vol. xviii.) 
τς: Hollow bellowings is a common expression with narrators. The describer 
of the New Zealand earthquake of 1848 (West. Rev., p. 397, for July 1849) 
| says, “ The earth is in a continual state of tremulousness, and the dull sound 
| of the earthquake is continually heard. This sound has been much ex- 
_ aggerated ; it is something like the sound of a railway train rumbling through 
Ἄς a tunnel, I mean as heard by a person outside and near the mouth. I have 
also heard nearly a similar sound made by a very large steam ship chimney, 
