114 Scienti/ic Proceedings, Royal Dublin Society. 



and skill of engineers and agriculturists, may he utilized in 

 improving the unproductive or waste lands of the country. 



These unproductive lands may be generally classed as Flooded 

 Lands either by the sea, lakes, rivers, or streams; Lowland, 

 or Red Bogs ; Mountain Bogs ; Mountainous tracts ; Upland 

 Wastes, and Blown Sands. 



A saying of the great Nimmo, often repeated in the west of 

 Ireland, was — " Give me money and men, and I will make a road 

 across Dingle Bay." Whether it be true or not that nearly, 

 everything is possible to the engineer, in the matter of the in- 

 taking of land we have very seldom to consider the possibility or 

 impossibility of the work to be done, but only by what means it 

 can be carried out at the least expense, so as to be at the same 

 time perfectly effective and profitable ; and it is here that the 

 geologist can help the engineer. 



As to the reclamation of lands flooded by the sea — the kind of 

 sea-wall that would be likely to suggest itself, on first thoughts, 

 is a structure, which from its simple massiveness would be able 

 to resist the advance of the sea by main force and keep it back. 

 But such a barrier would be necessarily very costly, and we find, 

 after a study of the subject, that a judiciously planned and cheaper 

 defence may be far better. First, then, as to the construction of 

 the wall itself ; as I pointed out in a paper read before the Insti- 

 tution of Civil Engineers of Ireland, steep rocky shores present con- 

 ditions which are favourable for the waves dashing up to greater 

 or less heights ; while sands, shingles, and the like, absorb, as it 

 were, and destroy the force of waves ; more especially when a 

 beach slopes at different angles. This subject has received 

 considerable attention from the Dutch engineers, who now make 

 their embankments after the best natural form, that is of slopes 

 and flats (cesses) combined. Thus they are enabled to break 

 the force of any wave. They have also learned that nearly any 

 materials will do for the body of the bank (they generally use 

 the sand from outside the embankment), as its stability depends 

 principally on its faces ; these they make staunch, not by heavy 

 stone work (except under peculiar circumstances) but with clay, 

 wood, fascines, and the like, as the face of the bank is generally 

 only for a temporary purpose, that is, to preserve the structure 

 while a strand is being hanked up against it by tidal or other 



