1901.] . HAUPT — METHODS OF IMPROVING OCEAN BARS. 7S 



ing from the same base to a distance of about 3150 feet. Beyond 

 that we have the old Government jetty, a submerged structure, 

 but still a jetty capable of exercising an important influence on the 

 tidal flow a further distance of 2350 feet, making a north jetty hav- 

 ing a total length of 6350 feet and a south jetty having a total length 

 of 5500 and located about 1250 feet apart." 



Again, to a novice these statements are grossly misleading, since 

 the old Nelson jetty, which was built of wooden cylinders filled with 

 sand, was destroyed where exposed to the sea soon after it was 

 placed, as was predicted. It long since ceased to act as a jetty 

 (see map, Fig. 6, in the report). There has been no revetment 

 placed on Mustang Island for more than a decade, and its outer 

 shore line has apparently advanced between January, 1899, and May, 

 1900, only about 500 feet; but this was after the depths as reported 

 were secured (see Maps 5 and 6), and hence could not have been 

 instrumental in causing them. Moreover, the old Government jetty 

 is not only " submerged" but subterranean, being buried under 

 the sand which the reaction breakwater has thrown over it ; and 

 hence being in a region of deposit, not of scour, and being under 

 ground, it cannot be regarded as "capable of exercising an impor- 

 tant influence on the tidal flow" as an active agent to confine the 

 currents, and thus the fallacy of the two jetties 1250 feet apart is 

 reduced to the effective portion of about 1500 feet of the break- 

 water extending above high water and the unfinished submerged 

 flank of the same, partially overlapping the outer end of Mustang 

 Island, but having gaps of fifteen feet and less in depth. The sand- 

 bank on the southerly side of the channel is the dump for the ma- 

 terial removed by the breakwater, and is the effect, not the cause, of 

 the deepening created by it. The theory that these results are due 

 to two jetties is wholly without foundation in fact. 



Another serious error into which the author has fallen is in deter- 

 mining the direction of the resultant drift, which furnishes the key 

 to the correct solution of the problem by a single jetty. He insists 

 that all the charts which were accessible, as well as the statements of 

 more or less interested parties, were to the effect that the resultant 

 movement was from south to north, and that since the breakwater is 

 on the north side it is therefore located to leeward and not to wind- 

 ward, as it should be according to the theory of the writer, fie 

 discusses the anemometer records, and although they show that the 

 intensity of the northeast storms is to that of the southeast as 43. 7 is 



