WHIRLPOOLS AND EDDIES. 39 



doubling the Cape, finds herself followed for weeks at a time by these 

 magnificent rolling swells, furiously driven and lashed by the * brave 

 west winds.' These billows are said to attain the height of thirty, 

 and even forty feet ; but no very exact measurement of the height of 

 waves is recorded." One of these mountain waves placed between 

 two ships conceals each of them from the other an effect which is 

 partially represented in Fig. 7. In rounding Cape Horn, waves are 

 encountered from twenty to thirty feet high ; but in the Channel they 

 rarely exceed the height of nine or ten feet, except when they come 

 in contact with some powerful resisting obstacle. Thus, when billows 

 are dashed violently against the Eddystone Lighthouse, the spray 

 goes right over the building, which stands 130 feet above the sea, and 

 falls in torrents on the roof. After the storm of Barbadoes, in 1780, 

 some old guns were found on the shore, which had been thrown up 

 from the bottom of the sea by the force of the tempest. 



If the waves, in their reflux, meet with obstacles, whirlpools and 

 whirlwinds are the result the former the terror of navigators. Such 

 are the whirlpools known in the Straits of Messina, between the 

 rocks of Charybdis and Scylla, celebrated as the terror of ancient 

 mariners, and which were sung by Homer, Ovid, and Virgil : 



"Scylla latus dextrum, Ijevnm irrequieta Charybdis, 

 Infestat ; vorat haec raptis revomitque carinas. 



Incidit in Scyllam, cupiens vitare Charybdim." 



These rocks are better understood and less feared in our days. At 

 Charybdis there is a foaming whirlpool ; at Scylla the waves dash 

 against the low wall of rock which forms the promontory, and are 

 scarcely noticed by the navigator of our days. 



Another celebrated whirlpool is that of Euripus, near the Island 

 of Eubcea ; another is known in the Gulf of Bothnia. But perhaps 

 the best known whirlpool is the Maelstrom, whose waters have a 

 gyratory movement, producing a whirlpool at certain states oi the 

 tide, the result of opposing currents, which change every six hours, 

 and which, from its power and magnitude, was at one time thought 

 capable of attracting and engulfing ships to their destruction, although 

 it is now known not to be dangerous even to very small craft. 



To the combined effects of tides and cyclones may also be attri- 

 buted the hurricanes, so dreaded by navigators, which so frequently 

 visit the Mauritius and other parts of the Indian Ocean. In periods 

 of the utmost calm, when there is scarcely a breath to ruffle the air, 

 these shores are sometimes visited by immense waves, accompanied 



