[67] LISTS OF DREDGING STATIONS. 939 



Aves Islet, 100 miles westward of Gaadaloupe^ was found to be the 

 summit of a mountaiu, precipitous on its western slope and extending 

 in a soutli-soutbeast direction over 150 miles to the 1 ,000-fatliom curve. 



During the summer and autumn of 1884 hydrographic work was 

 mer;]}- incidental, as continuous dredging and trawling generally inter- 

 fered with the correct locating of the stations. Still, a number of the 

 feoundings taken were considered plotted with sufficient accuracy to be 

 of hydrographic value. This work was off the United States coast 

 between Cape Hatteras and George's Banks. 



!N'othing of special interest was definitely ascertained. But in the 

 course of the season it became very evident that in the vicinity of the 

 40th parallel and the 70th and 71st meridians there is an easterly and 

 a westerly movement of the water, alternating at intervals of apparently 

 about half a day. Circumstances i)revented a close examination into 

 this matter, but, as the approximate time of the change of the current 

 was noticed on several occasions to be later each day, it is believed that 

 the phenomenon may be attributed to the influence of the moon, and 

 that probably there may be tidal currents, less pronounced, but as regu- 

 lar there as along shore. 



Indications were also found of a pocket running in northward from 

 the GOOfathom line on about the meridian of 70^ 15', differing from the 

 contour lines on existing charts. But, owing to cloudy weather and the 

 impossibility of keeping a good reckoning w^hile trawling, the positions 

 found were not considered sufficiently reliable to warrant making a 

 report to the Hydrographic Office. 



