HITORY OF THE WHALE. 85 



putrefaction commences, it swells to an enormous size, till 

 at least a third of the carcass appears above water, and 

 sometimes the body is burst by the force of the air genera- 

 ted within. 



Bulky as the whale is, and clumsy as it appears to be, it 

 might be imagined that all its motions must be sluggish, 

 and its greatest exertions productive of no great celerity. 

 The fact, however, is the reverse. A whale extended mo- 

 tionless at the surface of the sea, can sink, in the space of 

 six seconds, beyond the reach of its human enemies. Its 

 velocity along the surface, and in other directions, is the 

 same, I have observed, says Scorseby, a whale descend- 

 ing, after I had harpooned it, to the 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 dart- 

 ing 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 per- 

 form apparently as an amusement, to the high admiration 

 of the distant spectator ; but to the no small terror of the 

 inexperienced fisher. Sometimes the whales throw them- 

 selves into a perpendicular position, with their heads down- 

 wards, 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 vapors. 

 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 water, and so dis- 

 appears. 



