SCIENCE-GOSSIP. 



67 



of their susceptibility to the erosive action of rain 

 and the atmosphere. The gorge sides and cliff 

 faces are everywhere pierced with caverns and 

 fissures, few of which, however, attain to any 

 considerable size. This is due to the nature of 

 the rocks in which they have been formed, as, 

 owing to the comparative softness of the lime- 

 stones, the caverns usually collapse when they 

 reach a certain limit. 



Examples of the former class occur all round 

 the coast lines of the islands, but they are to be 

 seen to the best advantage wherever the Upper 

 Coralline Limestone appears at the sea-level along 

 the coast. The varied and romantic scenery of 

 the western coast of Comino owes its picturesque 

 character entirely to the beetling crags and 

 cavernous hollows with which its shore cliffs are 

 everywhere adorned. Compared with the cliffs of 



Map showing the relationship of the Maltese Islands to the Continents of Europe and Africa. 



Maltese caverns may be divided into two classes, 

 those that have been formed by the mechanical 

 erosion of the sea, assisted by the chemical 

 processes of the atmosphere, and those that owe 

 their origin to the wasting effect of rainwater 

 saturated with carbon dioxide, which percolates 

 through the porous strata, or obtains access 

 through the fissures or along the bedding planes 

 of the rock. 



Gozo and those along the south coast of Malta, 

 Comino's crags may appear insignificant ; but 

 their want of altitude is fully compensated for by 

 the wildness of their surroundings and the pictur- 

 esque groupings of their caverns and of the 

 detached rock masses that lie along their bases. 

 The resistless onslaught of the battering forces 

 of the Gregale and the Levante, two winds that 

 alternately rage in the Mediterranean during the 



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