402 HARBOR AND COAST IMPROVEMENTS. 
Great Works of Material Improvement. 
Men have ceased to admire the vain exercise of power which 
heaped up the great pyramid to gratify the pride of a despot 
with a giant sepulchre; for many great harbors, many impor- 
tant lines of internal communication, in the civilized world, 
now exhibit works which in volume and weight of material sur- 
pass the vastest remains of ancient architectural art, and demand 
the exercise of far greater constructive skill and involve a much 
heavier pecuniary expenditure than would now be required for 
the building of the tomb of Cheops. It is computed that the 
great pyramid, the solid contents of which when complete were 
about 8,000,000 cubic yards, could be erected for a million of 
pounds sterling. The breakwater at Cherbourg, founded in 
rough water sixty feet deep, at an average distance of more 
than two miles from the shore, contains double the mass of the 
pyramid, and many a comparatively unimportant canal has been 
constructed at twice the cost which would now build that stu- 
pendous monument. 
The description of works of harbor and coast improvement 
which have only an economical value, not a true geographical 
importance, does not come. within the plan of the present vol- 
ume, and in treating this branch of my subject, I shall confine 
myself to such as are designed either to gain new soil by ex- 
cluding the waters from grounds which they had permanently 
or occasionally covered, or to resist new encroachments of the 
sea upon the land.* 
ces are borne with so little effort to remove them, and especially that break- 
waters are rarely constructed by Governments except for the benefit of the 
military marine. 
* Some notice of great works executed by man in foreign lands, and prob- 
ably not generally familiar to my readers, may, however, prove not uninter- 
esting. 
The desaguadero, or canal constructed by the Viceroy Revillagigedo to pre- 
vent the inundation of the city of Mexico by the lakes in its vicinity, besides 
