114 
plikt's katijeal histoet. 
[Book II. 
CHAP. 83. (81.) — STG^S OP A^f APPEOACHIKG EAllTJI QUAKE. 
Tliere is no doubt tliat earthquakes are felt by persons on 
sliipboard, as tliej are struck by a sudden motion of the 
waves, without these being raised by any gust of wind. 
And things that are in the ressels shake as they do in houses, 
and give notice by their creaking ; also the birds, when they 
settle upon the vessels, are not without their alarms. There 
is also a sign in the heavens ; for, when a shock is near at 
hand, either in the daytime or a little after sunset, a cloud 
is stretched out in the clear sky, like a long thin line\ The 
water in wells is also more turbid than usual, and it emits a 
disagreeable odour^. 
CHAP. 84. (82.) — PEESEEYATIYES AaAIT^TST PUTUEE 
EARTHQUAKE S. 
These same places^, however, aiTord protection, and this is 
also the case where there is a number of caverns, for they 
give vent to the confined vapour, a circumstance which has 
been rem arked in certain towns, which have been less shaken 
where they have been excavated by many sewers. And, in 
the same town, those parts that are excavated'^ are safer than 
the other parts, as is understood to be the case at JN^aples in 
Italy, the part of it which is solid bemg more liable to injury. 
Arched buildings are also the most safe, also the angles of 
walls, the shocks counteracting each other ; walls made of 
brick also suffer less from the shocks^. There is also a great 
^ This observation is taken from Aristotle, Meteor, ii. 8. 
2 Phsenomena of this kind have been frequently noticed, and are not 
difficult of explanation. 
2 "In iisdem " lidem, inquit, putei inclusum terra spiritum libero 
meatu eniittentes, terrse motus avertunt." Alexandre in Lemaire, i. 406. 
" Quae pendent." M. Ajasson translates this passage, " qui sonfc 
comme suspendues." Hardoum's explanation is, " Structis fornice ca- 
meris imposita sedificia intelhgit ; quod genus camerarum spiramenta 
plerumque habet non pauca, quibus exeat ad libertatem aer." Lemaire, 
i.407. 
^ Many of these circumstances are referred to by Seneca., ISTat. Qugest. 
vi. 30. On the superior security of brick buildings, M. Alexandi^e 
remarks, " Muri e lateribus facti difBcihus quam cseteri dehiscunt, undo 
fit ut in urbibus muniendis id construe tionum genus plerumque prg)- 
feratur. Ex antiquse Itahse palatiis tempHsve nihil fere pra^ter immensas 
iaterum moles hodie superest." 
