§ 754, 755. TIDE-RIPS AND SEA DRIFT. 405 



frequently seen when there is no perceptible current. Although 

 there is no perceptible current experienced so as to produce an er- 

 ror in the course and distance sailed, yet the surface of the water 

 is impelled forward by some undiscovered cause. The ripplings 

 are seen in calm weather approaching from a distance, and in the 

 night their noise is heard a considerable time before they come 

 near. They beat against the sides of a ship with great violence, 

 and pass on, the spray sometimes coming on deck ; and a small 

 boat could not always resist the turbulence of these remarkable 

 ripplings." 



754. Captain Higgins, of the " Maria," when bound from New 

 Tide-rips in the Atian- York to Brazil, thus describes, in his abstract log, 

 ^^^ one of these ^'tide-rips," as seen by him, 10th Oc- 

 tober, 1855, in N. lat. 14°, W. long. 34° : " At 3 P.M. saw a tide- 

 rip; in the centre, temp, air 80°, w^ater 81°. From the time it 

 was seen to windward, about three to five miles, until it had pass- 

 ed to leeward out of sight, it was not five minutes. I should 

 judge it traveled at not less than sixty miles per hour, or as fast 

 as the bores of India. Although we have passed through several 

 during the night, we do not find they have set the ship to the 

 westward any ; it may be that they are so soon passed that they 

 have no influence on the ship, but they certainly beat very hard 

 against the ship's sides, and jarred her all over. They are felt 

 even when below, and will wake one out of sleep." 



755. Captain Wakeman, of the '' Adelaide," in January, 1856, 

 Mock vigia.. lat. 11° 2V K, long. 33° 33' W., encountered '' tide- 

 rips" which broke and foamed with such violence that he took 

 them for breakers or a shoal. They sometimes are most alarm- 

 ing. Approaching through the stillness of the night with a roar- 

 ing noise, and in the shape of tremendous rollers combing and 

 foaming, they seem to threaten^ to overwhelm vessel and crew; 

 but, breaking over the deck, they pass by, and in a few moments 

 the sea is as smooth and as unrufiled as before. Many of the 

 " vigias" which disfigure our charts have no other foundation thapi 

 the -foam of a tide-rip. Captain Arquit's log of the " Comet" 

 gives an account of many tide-rips which he encountered also in 

 the northeast trade-wind region of the Atlantic. Thus, Kovember 

 15, 1855, lat. 7° 34' N., long. 40° 30' W. : " Many tide-rips, which 

 we had a good opportunity of observing when becalmed. They 



