226 H. W.Pearson — Oscillations of Sea- level. 



Elisee Keclus, in "■ The Earth," discusses at length the subject of 

 upheaval and depression of shore-lines ; he shows the inability of 

 sedimentary processes to account for the shoaling of the manj'^ ports 

 of the Mediterranean or for the advance of the coastlines into the 

 sea ; he says, in these matters, " we are witnessing the phenomena 

 of a vertical impulse " (p. 539) ; on p. 542 he shows us that this 

 "vertical impulse" has affected the entire area of the Mediterranean. 

 The study of these and similar upheavals and depressions over the 

 earth's surface leads him to say : " As will be understood, these 

 regular oscillations must take place in obedience to some general 

 law still unknown, although none the less certain" (p. 566). We 

 should note here, that while Eeclus attributes these oscillations to 

 movements of the earth, it is impossible to distinguish such move- 

 ments from oscillations in the sea ; the effect is precisely the same in 

 either case. 



Eear- Admiral Smyth seems to have noted these oscillations ; he 

 says : " It is decided, upon what appears to be sound geological 

 evidence, that a great part of the Italian coast has been raised and 

 lowered several times within the historical era, while the sea must 

 have ever maintained the same level " (" The Mediterranean," p. 26). 

 Again, on p. 28 he remarks : " It may be safely concluded that the 

 land has risen and fallen twice since the Christian era, and that each 

 movement of elevation and subsidence has exceeded twenty feet." 



Mr. P. Thompson, in "The History and Antiquities of Boston," 

 has shown that these same oscillations have occurred in the Fens 

 of England. On p. 660 he demonstrates these changes to have been 

 four in number since the time of the Eomans, two periods of 

 inundation and two periods of desiccation, but these periods can 

 also be determined from the data attached to this argument. Oscil- 

 lations of the sea-level have also been shown at Rye and Winchelsea 

 and in the English Channel, the latter by Peacock. 



We note, however, that the above quoted authorities, although 

 they may have suspected these oscillations, or may have actually 

 observed them, have in no case attempted to control these phenomena 

 by law or to determine the period of vibration. Law has been 

 invoked, however, by Professor Edouard Suess and by Trautschold, 

 a quotation from this latter having been previously given, notwith- 

 standing the " resolve to abandon the doctrine of secular oscillations 

 of continents " (Suess), and the adoption of periodic fluctuations 

 in the sea-level in its stead. I am unable to learn that either of 

 these gentlemen has attempted determination of the period of these 

 fluctuations ; it may therefore be possible that this is the first attempt 

 in that direction. 



I show no curve beyond the 400 b.c. At this period the evidence 

 which I have been able to collect becomes uncertain, scanty, and 

 the dates are very unreliable. The Deucalion Deluge, the Ogygian 

 Deluge, and the Deluge of Samothrace furnish data at remote and 

 uncertain periods. The books of Homer, of Herodotus, of Strabo, 

 of Ptolemy, and other ancient writers supply much information as 

 to the position of the sea-level at periods from 600 to 200 b.c. ; but 



