224 M. L. FULLER THE SEA MILLS OF CEPHALONIA 



tered at a depth of 225 feet, or well below the level of the surrounding 

 sea (P, figure 2). The Cretaceous limestones, according to descriptions, 

 appear to lie on ancient crystalline rocks. 



SPRiNas 



Inasmuch as the water entering the limestone at the sea mills must 

 reappear at the surface elsewhere — possibly even above sealevel — the 

 occurrence of springs is of special interest. According to all authorities, 

 however, there are no saline or thermal springs on the island of Cepha- 

 lonia, nor on the adjacent portions of the mainland, although in other 

 parts of Greece, especially in the eastern portion, a considerable number 

 of brackish springs discharge continuously enormous volumes of water,* 

 but they do not appear to be noticeably thermal. Thermal springs are, 

 however, found at a number of points, including several on the island of 

 Eubcea, in eastern Greece. 



NATURE OF THE FISSURES 



The water at the sea mills seems to follow enlarged joint cracks, and it 

 is probable that parts of the deeper passages of the circulating system are 

 of the same origin. Crosby and Crosby, however, lay great stress on the 

 action of earthquakes. These are very numerous and of great severity, 

 and some of them apparently have had their foci at no great distance 

 from Cephalonia. Marked iissuring has accompanied several of the 

 disturbances elsewhere in Greece, and some springs have ceased to flow, 

 while others have had their discharge greatly increased. That the waters 

 reach considerable depth in the fissures is shown by the temperatures, 

 which in eastern Greece are as high as 82° centigrade in some instances. 



Possible Causes of Circulation 



under&rovnd passages 



The flow at the sea mills, which has continued for an unknown period 

 of time — almost certainly for several centuries — is far too great for re- 

 moval by evaporation, chemical combination, or even physical absorption 

 by pores or caverns in the rocks, and the constant influx can only be 

 satisfactorily explained on the hypothesis that the passage into. which the 

 water disappears is a part of a definite circulatory system through which 

 the water passes to some point of emergence, Avhich, whether it be above 



* Crosby and Crosby : Loc. cit., p. 18. ' • 



