152 PROCEEDINGS OF THE AMERICAN ACADEMY. 



generation of men, it is practically in the same position, yet even in the 

 short period of historic time records show that villages have been sub- 

 merged, or that seaport towns have been turned into inland places. 

 The historical side of this problem is not to be here discussed, nor is 

 the cause of the secular movements of the earth's crust, including the 

 question of isostasy, here considered. 



As dwellers upon the land, we look at the change in the relative posi- 

 tion of land and water as it affects our position. Thus " the land rises," 

 " the coast sinks," are the common expressions of man. If the point of 

 view was that of the inhabitants of the sea, the expressions would be 

 reversed, the sea sinks when the land rises and rises when the land is 

 depressed. It will be convenient in this paper to use the terms elevation, 

 uplift, emergence, raised, etc., and their opposites, depression, submer- 

 gence, sunken, etc., in reference to the land. Such use is not intended 

 to imply "a limitation of movement to the land, excluding that of the sea 

 floor, but is to describe the geographic efTects from the standpoint of 

 man, who lives upon the dry land. 



The shrinking of the mass of oceanic waters will also cause the land 

 apparently to rise to the same amount all over the world.* 



By the draining of lakes many characteristic forms of shore develop- 

 ment will be exposed, which are here classed with forms following up- 

 lift; while the increase of water in a lake for any cause will give the 

 same forms as are produced by a depression of the land. 



The relation of the accumulation of glaciers to changes of elevation, 

 and the evidence afforded by coral islands to show rising or sinking 

 regions, are two problems for solution which are not attempted by the 

 present writer. 



Use of Terms. — Throughout this paper the author uses shoreline for 

 the line of intersection of the sea with the land. The region immedi- 

 ately to the landward of the shoreline is called the coast, and seaward 

 from this line the shore. Thus cliffs and deltas are coastal features, while 

 waves advance and retreat along the shore. 



In the figures the older mainland is cross-hatched, while forelands are 

 left blank. The observer is supposed to look from the point of view of 

 the sea as it attacks the land, therefore the two sides of the figures will 

 be spoken of as the right and left respectively as seen from the sea look- 

 ing toward the land. 



* The effect in inland seas with imperfect outflow has been discussed by Prof. 

 Suess, Anzeiger d. k. Akad. d. Wiss., 1887, XXIV. 180-182. 



