158 PROCEEDINGS OP THE AMERICAN ACADEMY. 



parison of the facts used as criteria of rising and sinking in central and 

 southern Europe. For our present purpose, however, it will suffice to 

 indicate how loosely criteria have been interpreted. Compare the two 

 maps referred to above with that of France by Girard.* Each of the 

 three differs from both of the others. Southwestern France, the Landes 

 coast, is given by Credner as sinking, by Reclus as rising, and by Girard 

 as sinking in some places and rising in others. 



Algebraic Sum of Movements : Maine. — The position of the land in the 

 present cycle is determined by the algebraic sum of all past oscillations. 

 The form is due to development in (n + 1) cycles. Cycles and epicycles 

 previous to tlie present may be recognized in inverse proportion to the 

 time since their close, and in direct proportion to the stage of develop- 

 ment reached in said cycle or epicycle. A region is classed in this paper, 

 as in a certain stage of development following elevation or depression, 

 according to the larger facts of form prevailing in the region. 



For example, the coast of Maine (Figure 1) is on the whole a depressed 

 region. It has numerous islands, bays, etc., showing drowned topography 

 in a youthful stage of development. At Ogtniquit,| however, as well as 

 in other parts of this area, are seen criteria of elevation, elevated shore- 

 line, narrow coastal plain, nip, lagoon, and enclosing ofTshore bar. Since 

 the greatest depression, there has been an episode of elevation. The 

 development of the sequential features, following the initiation of a new 

 cycle of depression, has been interrupted by this episode or epicycle of 

 elevation. 



Figure 2. Diagram sliowing Mutual Relations of Cycle, Epicycle, and Vibration. 



Cycle, Epicycle, and Vibration, Neio Jersey ; Scandinavia. — It is only 

 to the larger movements of the land to which the term cycle is applica- 

 ble. The minor ups and downs of the coast are but portions of a cycle, 

 each of which may be called an epicycle, which in turn may be made 

 up of various smaller swings or vibrations. The relations of these 

 various movements to one another is shown in the accompanying diagram 

 (Figure 2). 



* Soulevements et depressions du sol sur les cotes de France, Bull. Soc. Geog., 

 1875, X. 225, etla carte, 

 t See pp. 185, 188. 



