84 HAUPT — METHODS OF IMPROVING OCEAN BARS. [May 3, 



It may well be asked why no one had previously discovered that 

 a channel could have been secured here for the petty sum of 

 1 1 8, 750, and, if so, why it was not done instead of estimating mil- 

 lions of dollars for jetties and dredging plants, or why is not a per- 

 manent channel secured at other points on our alluvial coasts for 

 similar trifling expenditures ? 



The fact is that this is not a dredged channel, but one secured by 

 the effect of violent explosives on the bar which assisted the ebb 

 currents to select and create the best path to sea, and no credit is 

 given in the account to the large excess of material which was 

 removed by such explosions. Any estimates, therefore, based on 

 net measurements in place are utterly unreliable and the resulting 

 price per unit is of no value in ascertaining the cost. The only 

 reliable method is the cost per foot of depth actually secured, and 

 on this basis the work has cost only about ten per cent, of that else- 

 where, with far better and more permanent results. Hence dredg- 

 ing alone should not be recommended. 



In a science necessarily so empirical as this it would seem that the 

 best guide to results would be to make a careful diagnosis of the 

 natural conditions and forces available, and then utilize them to the 

 best advantage. This was the plan pursued at Aransas Pass, which 

 is conceded to be the only instance of the kind on record ; while the 

 author would have it appear that it is fatally defective and is 

 merely a case of two jetties. But no two jetties, so far as the 

 writer's researches have gone, can be cited which have produced 

 like results in practice with a tide of but fourteen inches, and with 

 an obstructing wall across the bottom of the channel. 



In conclusion, it would seem that of the several methods proposed 

 for bar removal by the use of single or double jetties or by the reac- 

 tion breakwater, the latter, so far as it has been tested, fulfills 

 better than any other the conflicting requirements of harbor 

 entrances, costs less than half as much and is far cheaper to main- 

 tain. Had this plan been adopted in 1888 it is believed, in view 

 of subsequent events, that it would have saved the Government not 

 less than $25,000,000 in the cost of jetty or breakwater construction 

 and at least as much more (if capitalized) in the cost of maintenance, 

 while the indirect benefits to commerce resulting from an earlier 

 opening of our seaports for deep vessels would have exceeded the 

 sum of both of these items. 



