120 On the Cause of the Earthquakes hi the lofinan Isles. 



up water (itself perhaps an occasional cause of earthquakes), or 

 with the falling in of great masses of clay, supposing, as there 

 IS every reason to believe, that in regions subject to earthquakes 

 there exist extensive subterraneous cavities. You will natu- 

 rally ask, how do the facts which are best ascertained respecting 

 the localities of earthquakes in the Ionian islands, and their phe- 

 nomena, accord with this idea ? 



To me they appear to accord so well as to be a confirmation 

 of it. I shall notice some of the facts which I conceive to be 

 most important and unquestionably authenticated. 



1. Earthquakes are most common in the clay districts, as in 

 the low parts of Zante, which consist chiefly of grey marl ; in 

 most parts of Santa Maura, where the same marl is abundant ; 

 in the low parts of Cephalonia^ especially the neighbourhood of 

 Lixuri and Angostoli, also abounding in marl ; and in the dis- 

 trict of Alleschimo, in Corfu, which consists almost entirely of 

 marl. 



2. Earthquakes are rarely felt, and slightly, in those parts of 

 the islands which consist chiefly of rock, whether of mountain 

 limestone, as the mountainous parts of Zante and Cephalonia ; 

 or of mountain limestone and clay-slate, as the loftiest part of 

 Corfu, or of the same rock associated, on a small scale, with pri- 

 mitive marble and granite, as in the most elevated region of 

 Cerigo. I would beg to dwell a little on this point of locality. 

 Zante, in the different regions just alluded to, offers a very 

 striking contrast. The frequency of earthquakes in the town of 

 Zante, and its immediate neighbourhood, is universally known. 

 In the summer and autumn of 1824, which I chiefly spent there, 

 hardly a day passed without a shock being felt, and almost 

 every house bore marks of having, more or less, suffered from 

 them ; and this town is situated on marl, and backed by lofty 

 hills of the same substance. The exemption of the mountainous 

 regions, composed of limestone, constituting nearly half of the 

 island, is but little known, if at all. When I travelled through 

 it the same year, I did not fail to make inquiries on the subject, 

 wherever I went; and I was invariably answered, as I have just 

 stated, that earthquakes there were rarely indeed felt, and only 

 very slightly. In Santa Maura, it is deserving of notice, there 

 is one village which has always been remarkable for exemption, 



