THE JURA. 
31 
extended from Orbe on the west to Soleure on the 
east. The basin is formed by one, or rather two, of 
the longitudinal Jura valleys. I say two because a 
ridge of Marine Mollasse, commencing at the hill of 
Chamblon near Yverdun, runs along the centre of 
the lake, forms the Jolimont between the Lake of 
Neuchatel and Bienne, and continues along the centre 
of the Lake of Bienne, forming a ridge over 400 feet 
in height, and appearing above the surface as the 
Isle de St. Pierre. In fact, if the level of the water 
was reduced the Lakes of Neuchatel and Bienne 
would each be resolved into two narrow lakes; while 
if the water rose they would form a single sheet with 
the Lake of Morat. 
