70 HAUPT — METHODS OF IMPROVING OCEAN BAR*. [May 3, 



barrier between the channel and the advancing drift, or to wind- 

 ward and not to leeward. Here where a jetty was built to leeward, 

 according to the author's ideas, the natural forces changed it to 

 windward by shifting the channel to the opposite side — a com- 

 plete demonstration in his own district. 



The report also shows that a deep and narrow channel is antici- 

 pated on the windward side of the jetty, for it says : 



"It is difficult to see how such a constant force from the north 

 could avoid crowding the channel close to the jetty and making it 

 sufficiently deep near the latter torequire extensive and expensive 

 work to prevent undermining." 



The results, however, are just the reverse of this as seen at Cum- 

 berland Sound, for the sand being heavier than water, when it 

 meets with an obstruction is dropped in the channel, if to wind- 

 ward, and fills it up. Yet notwithstanding these years of experience 

 and expense at Cumberland the report states: "The jetties so far 

 constructed at Cumberland Sound have not yet progressed suf- 

 ficiently far to have much influence upon the bar depths." 



On the contrary, the author might have said with more truth, 

 they have had so great an influence upon the bar depths as to have 

 entirely obliterated the old channel, and to have created a new 

 one which now crosses the south jetty through the breach made to 

 admit light draught vessels to the port. The depth has not been 

 increased. 



A somewhat similar experience occurred at Manasquan inlet on 

 the New Jersey coast, where the jetties were completely buried 

 under a sand bank and appropriations were requested to remove. the 

 obstructions. These lessons of experience are lost upon a con- 

 stantly shifting personnel and they have cost the Government much 

 time and money, whereas the bar depths have not been materially 

 increased by the application of natural forces. In recent years, by 

 localizing the channel at the mouth of the Columbia, there was a 

 temporary gain of about four feet at a cost of $500,000 per foot ; and 

 at Galveston of thirteen feet, mainly by dredging, costing nearly 

 $700,000 per foot to date. The total expenditures by the Govern- 

 ment on its works at Aransas Pass, Galveston, Coos Bay, Columbia 

 Bar, Cumberland Sound, St. John's River and Gray's Harbor, 

 where in most cases the leeward jetty was built first with injurious 

 results, have been about seventeen millions of dollars ($17,000,000) 

 and still the same method is urged as being the proper policy to 

 pursue. 



