THE DISTRICT OF COLUMBIA 323 



evidence of the Lafayette formation. Thus, the period of the 

 shaping of the plateau may be correlated with the period closed 

 by the deposition of the formation. 



The great gorges of the Potomac, and Anacostia and of Rock 

 creek and other tributaries tell of a period when the land stood 

 high above its present level ; and this is in accord with the 

 degradation of the greater part of the Lafayette, and permits 

 correlation of the land-forms in the two provinces. 



The lining of the Washington amphitheater with Columbia 

 deposits records a period when the land stood low and when the 

 climate was cold, and this gives a date for the correlation of 

 local geologic history with general geologic history. 



Thus the land- forms and the formations, when carefully studied 

 and interpreted, yield a record of the development of the District 

 during the ages : The streams flowed down to the sea, the waves 

 rolled along the shores, sediment was gathered here and de- 

 posited there, the earth-crust alternately heaved and sank ; as 

 time passed valleys were born and hills were fashioned, and the 

 face of the land was transformed again and again ; each new 

 geography was wrought from the old, and each can be restored 

 in mind or in picture from the study of hill and rock ; and each 

 stage in evolution was an .important episode in the geographic 

 development of the District of Columbia. 



THE HISTORICAL DEVELOPMENT OF THE NATIONAL 



.'CAPITAL 



By Marcus Baker* 



Among all the great capitals of the world the capital of the 

 United States stands out unique. In its origin, development, 

 and government, Washington has no counterpart. There is but 

 one Washington. That the National Capital is unlike other 

 cities in the United States is matter of common observation and 

 remark. Its wide, asphalt-covered avenues, its shaded streets, 

 its parks, and public statues — these outward shows usually first 

 arrest attention and excite comment. The roominess of the 

 streets and the leisurely air of those who use them are also often 



* Mr Marcus Baker, of the U. S. Geological Survey, was one of the founders and the 

 first Secretary of the Columbia Historical Society and is now Chairman of its Publica- 

 tion Committee. — Ed. 



