XXXVI. REVEGETATION OF TRESTLE ISLAND. 



D. LANGE. 



The piece of land I have named Trestle island lies in the 

 southwest part of Lake Phalen, near St. Paul, Minnesota. The 

 island consists of an East and a West section separated from 

 each other by a twenty-five foot embankment of the St. Paul 

 & Duluth Railroad. 



THE SEASON OF 1898. 



Up to the spring of 1898, the road maintained a trestle over 

 the shallow southeast bay' of Lake Phalen in place of the present 

 embankment. When the trestle was filled in between April 

 10, and June i, 1898, the gradually increasing weight of the 

 dumped material caused the soft lake bottom marl which, ac- 

 cording to the statement of the road's engineer, is from 6 to 35 

 feet thick, to slip out laterally ; and with many folds, wrinkles 

 and fissures it rose from a few inches to ten feet above low water 

 level of the lake. Although the engineer in charge tried to 

 prevent the slipping of the marl by means of pontoons, the 

 movement did not cease until about 2500 square yards of lake 

 bottom had risen and become dry land. Of this land about 

 1500 square yards rose east of the track out of 6 inches to 3 

 feet of water, and will be called the East section in this paper, 

 the other 1000 square yards rose West of the track out of 3 to 5 

 feet of water and will be referred to as the West section. Both 

 sections have been under the writer's observation from April 

 1898, to October 15, 1900, and it is intended to show in this 

 paper the most marked changes in the vegetation of Trestle 

 island. 



Early in June, 1898, both sections presented a curious system 

 of curved ridges and crevices running generally parallel to one 

 another and looking like miniature mountain ridges, valleys, 

 and gaping faults ; and even small lakes with snails and other 

 aquatic creatures were to be seen. Many of the crevices were 



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