ENCLOSING THE MARSCHES. 199 



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, raore.than 600 of them perished by 

 one of the concurrences of fatal circumstances already 

 defined. It was then that they undertook the astonish- 

 ing enterprise of enclosing these lands. They dug 

 ditches around all the marsches, heaping up on their exte- 

 rior 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 contribute more 

 to the safety of their dwellings, than to remove 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 process by which they 

 effected this, after I shall have recalled 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 un- 

 derstood, that the common effects of the waves and of the 

 tides is to bring materials from the bottom of the sea to- 

 wards the coasts ; and that the process continues in every 

 state of the sea. The land winds produce no waves on the 

 coasts, which carry back to the bottom of the sea what 

 has been brought thence by the winds blowing against 

 the shore ; and as for the tides, it may have been already 

 comprehended, (and shall soon by proved,) that the ebb 

 carries back but very little of what has been brought by 

 the flood. So that, but for some extraordinary circum- 

 itances, the materials continually impelled towards the 

 shore, which first form islands, would at last unite against 



