PLAINS OF THE ELBE AND WESEE, ETC. 



271 



able portions of them must have continued under water. The remains of these 

 ancient lakes are few and insignificant. The Diimmersee and the Steinhuder Meer 

 are mere shallow ponds. The ancient gulfs and lakes have long ere this been 

 filled up by an accumulation of peat, and peat bogs cover hundreds of square 

 miles. The most extensive of these tracts of land is the Morass of Bourtan^e, 



Fig. 155. — The Morass, or "Moor," of Bourtange. 

 Scale 1 : 206,000. 



5 Miles. 



which covers some 540 square miles to the west of the Lower Ems, and is inter- 

 sected by the boundaiy separating Hanover from the Netherlands. The human 

 habitations built in this swamp rise gradually above the horizon as we approach 

 them, like ships on the ocean. It would be dangerous to venture without a 

 guide upon the quaking and treacherous soil of the morass. The natives who 

 cross it make use of leaping-poles, to the end of which is fastened a plank, to 



