22 



THE GLACIAL LAKE AGASSIZ. 



an apparent vertical distance of 75 or 100 feet for objects at a distance of 

 6 or 8 miles, and 300 to 500 feet if the view is 15 to 20 miles away. 

 Immediately above the inverted images there runs a level false horizon, 

 which rises slightly as the "saew grows less distinct, until, as it fades and 

 vanishes, the inverted groves, lone trees, church spires, elevators, and houses 

 at last resemble rags and tatters hung along a taut line. 



The traveler in the Red River Valley is reminded, in the same manner 

 as at sea, that the earth is round. The surface of the plain is seen only for 

 a distance of 3 or 4 miles; houses and grain stacks have their tops visible 

 first, after which, in approaching, they gradually come into full view; and 

 the highlands, 10 or 15 miles away, forming the side of the valley, 

 apparently lie beyond a wide depression, like a distant high coast. 



FlQ. 2.— Section across the Ked Kiver Valley on the latitude of Breckenridge and Wahpeton. Horizontal 

 scale, 20 miles to an inch : vertical scale, 1,000 feet to an inch. 



At Breckeiu'idge and Wahpeton, 35 miles nortli of Lake Traverse, the 

 surface of this plain is 960 feet above the sea (fig. 2). In 17 miles east it 

 ascends to 1,080 feet at the highest beach of Lake Agassiz; and on the 

 west it rises in 28 miles to 1,065 feet at the corresponding beach near 

 Wyndmere, beyond which for 8 miles farther west it maintains a level 2 to 

 5 feet below the crest of that beach. 



At Moorhead and Fargo, 75 miles north of Lake Traverse, the surface 

 adjoining the Red River is 900 to 905 feet above the sea (fig. 3). In the 

 first 15 miles east it ascends about 60 feet. The highest beach of Lake 

 Agassiz here lies at Muskoda, 17 miles east of the Red River, on the slope 

 of a highland of till, which rises in a distance of 6 or 8 miles to an 

 elevation of 250 feet above the flat Red River Valley, having thus an 



