SEALS AND WHALES OF THE BRLTISLL SEAS. 91 



in which the Whale moves ; consequently, the head, taken as a whole, is 

 lighter specifically than any other part of the body, and will always have a 

 tendency to rise at least so far above the surface as to elevate the nostril or 

 "blow-hole" sufficiently for all purposes of respiration; and more than this, a 

 very slight effort on the part of the fish would only be necessary to raise the 

 whole of the anterior flat surface of the nose out of the water. In case the 

 animal should wish to increase his speed to the utmost, the narrow inferior 

 surface, which has been before stated to bear some resemblance to the cut- 

 water of a ship, and which would, in fact, answer the same purpose to the 

 Whale, would be the only part exposed to the pressure of the water in front, 

 enabling him thus to pass with the greatest celerity and ease through the 

 boundless track of his wide domain."* When swimming at ease, the Sperm 

 Whale keeps just below the surface of the water, and goes at about three 

 or four miles an hour ; but on an emergency it is able to attain a speed 

 of ten or twelve miles an hour : it then progresses by means of powerful 

 lateral strokes of its tail, and alternately rises and sinks at each stroke. In 

 progressing in this manner, the blunt anterior surface of the head never 

 presents itself directly to the water ; the animal's bod}' being in an oblique 

 position, it is only the angle formed by the inferior surface which first presents 

 itself, and this, which Beale likens to the " cutwater" of a ship, oft'ers the least 

 possible amount of resistance. 



When undisturbed, the Sperm Whale rises to the surface to breathe 

 about once every hour. Beale says the regularity with which every action 

 connected with its breathing is performed is remarkable ; the time occu- 

 pied differs slightly in each individual, but each one is minutely regular 

 in the performance of every action connected with respiration, so that 

 the whalers know how long it will remain beneath the surface before re- 

 appearing to renew its supplj^ of air. A full-grown "bull," he saj's, remains 



* 'Natural History of the Sperm Whale,' p. 2$. 



