84 THE GREENLAND WHALE. 



depth of about one-fourth of a mile, with the average 

 velocity of seven or eight miles an hour. The usual 

 rate, however, at which these whales swim, when 

 on their passage from one situation to another, 

 seldom exceeds four miles an hour. They are 

 capable, however, for the space of a few minutes, 

 of darting through the water with the velocity of 

 the fastest ship under sail ; and of ascending with 

 such rapidity, as to leap entirely out of the water. 

 This feat they sometimes perform apparently as an 

 amusement, to the high admiration of the distant 

 spectator; but to the no small terror of the inex- 

 perienced fisher. Sometimes the whales throw 

 themselves into a perpendicular position, with their 

 heads downwards, and moving their tremendous 

 tails on high in the air, beat the water with awful 

 violence, which, cracking like a whip, resounds to 

 the distance of two or three miles ; the sea is thrown 

 into foam, and the air filled with vapours. This 

 performance is denominated " lob-tailing." 



When the animal retires from the surface, it first 

 lifts its head, then plunging it under water, elevates 

 its back like a segment of a sphere, deliberately 

 rounds it away towards the extremity, throws its 

 tail out of the water, and so disappears. 



The mysticetus usually remains at the surface to 

 breath about two minutes, seldom longer; during 

 this time it " blows" eight or nine times, and 

 then descends for an interval usually of five or ten 

 minutes; but sometimes, when feeding, fifteen or 

 twenty minutes. According to Scorseby, the right 



