H. W.Pearson — Oscillations of Sea- level. 227 



owing to the habit those ancient writers had of describing a city, 

 an island, a peninsula, or a coastline, in terms borrowed from some 

 still earlier and more ancient writer, it is at times difficult to decide 

 as to the particular date at which the description fitted the object. 

 The testimony so gathered is therefore very conflicting in its nature. 

 I believe, however, that we find the amplitude of vertical vibration 

 in the waters very much greater at that time than now, and the 

 period of change reduced to approximately 500 years. 



It is evident from what has gone before, that these oscillations 

 have had a continuous existence for the last 2,400 years. In this 

 paper we show strong evidence that these phenomena are periodic 

 in their nature, and that the periods of these cj'cles are capable of 

 determination. It is also equally evident, if any weight be attached 

 to the facts herein contained, that the whole Northern Hemisphere, 

 during the last three hundred yeai's or more, has been subject to 

 a general protrusion above the level of the sea. 



Let us now consider, then, those evidences as to present opposing 

 movement of shore-lines, to which attention has already been called ; 

 movements which, at the first glance, seem to deny so positively the 

 conclusions arrived at in the above discussion. 



To open the argument, I believe we maintain with great reason, 

 that if there has been a bodily transference during the last few- 

 centuries, of a considerable mass of water from the Northera 

 Hemisphere to the Southern, there must, coexistent with this 

 transfer, have been considerable decrease in flow of currents running 

 to the north and corresponding increase in currents flowing to 

 the south. 



Now then, acting on this assumption, the writer has shown in the 

 American Geologist for September, 1899, perfect explanation of 

 these apparently irregular motions ; it is there shown that every 

 observed case of apparent upheaval on one coastline, coincident 

 with subsidence on another, can be foretold by law, and that instead 

 of these motions being opposed to our conclusions, they are directly 

 confirmatory thereof, it being demonstrated that no transference 

 of water to the south can occur, no upheaval of northern shore- 

 lines can take place, without a corresponding subsidence on 

 the coasts of the Eastern United States, and also on the borders of 

 such other lands as may be similarly situated with regard to ocean 

 currents. 



I will not repeat all the arguments used in the paper mentioned, 

 but will state that our case hinges on the law of deformation of 

 ocean levels by ocean currents, as announced by William Ferrell 

 in Science, vol. vii. He says : " In the North Atlantic the 

 tendency to flow eastward in the middle and higher latitudes causes 

 a slight heaping up of the water and a rise of surface-level adjacent 

 to the coast of Europe, and a drawing away of the water and 

 a depression of sea-level along the north-east coast of the United 

 States " (p. 76). 



I have shown in the periodical mentioned that the waters 

 around the British Islands and on the Scandinavian shores are 



