594 CAPE COD CANAL. 



its ancient commercial importance. The work involved some of 

 the heaviest hydraulic operations yet undertaken, including the 

 construction of an artificial harbor of great dams, locks, dikes, em- 

 bankments, and the execution of draining-works and deep cuttings 

 under circumstances of extreme difficulty. In the course of these 

 labors many novel problems presented themselves for practical 

 solution by the ingenuity of modern engineers, and the new in- 

 ventions and processes thus necessitated are valuable contributions 

 to our means of physical improvement. 



Ccupe God Ccmal. 



The opening of a navigable cut through the narrow neck which 

 separates the southern part of Cape Cod Bay in Massachusetts 

 from the Atlantic, was long ago suggested, and there are few 

 coast improvements on the Atlantic shores of the United States 

 which are recommended by higher considerations of utility. It 

 would save the most important coasting trade of the United States 

 the long and dangerous navigation around Cape Cod, afford a new 

 and safer entrance to Boston harbor for vessels from Southern 

 ports, secure a choice of passages, thus permitting arrivals upon 

 the coast and departures from it at periods when wind and weather 

 might otherwise prevent them, and furnish a most valuable inter- 

 nal communication in case of coast blockade by foreign power. 

 The difficulties of the undertaking are no doubt formidable, but 

 the expense of maintenance and the uncertainty of the effects of 

 currents setting through the new strait are still more serious ob- 

 jections.* 



* The opening of a channel across Cape Cod woiild have, though perhaps to 

 a smaller extent, the same effects in interchanging the animal Uf e of the south- 

 em and northern shores of the isthmus, as in the case of the Suez Canal ; for 

 although the breadth of Cape Cod does not anywhere exceed twenty miles, 

 and is in some places reduced to one, it appears from the official reports on the 

 Natural History of Massachusetts, that the population of the opposite waters 

 differs widely in species. 



Not having the original documents at hand, I quote an extract from the Re- 

 port on the Invertebrate Animcds of Mass., given by Thoreau, Excursions, p. 

 69 : " The distribution of the marine shells is weU worthy of notice as a geo- 

 logical fact. Cape Cod, the right arm of the Commonwealth, reaches out into 

 the ocean some fifty or sixty miles. It is nowhere many miles wide ; but this 

 narrow point of land has hitherto proved a barrier to the migration of many 



