362 ON ALLUVIAL FORMATIONS. 



appears, that, in the winter, they assembled in greater- 

 numbers on the spots originally the highest, in the is- 

 lands, as well as on some parts of the coasts. 



Things continued in this state for several centuries ; 

 during which period, it is probable that the inhabitants 

 of these lands were often, by various catastrophes, dis- 

 turbed in the enjoyment of them, though not discoura- 

 ged. But in 516, by which time these people were be- 

 come very numerous, more than 600 of them perished 

 by one of the concurrences of fatal circumstances al- 

 ready defined. It was then that they undertook the as- 

 tonishing enterprise of enclosing these lands. They 

 dug ditches around all the marsches^ heaping up on their 

 exterior edge the earth which was taken out ; and thus 

 they opposed to the sea, dikes of eight feet in height. 

 After this, comprehending that nothing could contri- 

 bute more to the safety of their dwellings, than to re- 

 move the sea to a greater distance, they undertook, 

 with that view, to exclude it from the intervals between 

 the islands, by uniting, as far as should be possible, 

 those islands with each other. I will describe the pro- 

 cess by which they effected this, after I shall have re- 

 called to attention some circumstances leading to it. 



From all that I have already said of the fore-lands, 

 and of the manner in which they are increased, it may 

 be understood, that the common effects of the waves 

 and of the tides is to bring materials from the bottom of 

 the sea towards the coasts ; and that the process con- 

 tinues in every state of the sea. The land winds pro- 

 duce no waves on the coasts, which can carry back to 

 the bottom of the sea what has been brought thence by 

 the winds blowing against the shore ; and as for the 



