Proressor Borewui’s Experiments. 45 
which unite the greatest velocity with the greatest degree of 
strength must be reckoned the whale; for, struck with a har- 
poon or spear with a line attached, the leviathan of the waters 
darts down into the deep with such velocity that if the line 
were to entangle it would either be broken or the boat would 
be capsized. Upon the act of striking a whale, therefore, one 
man is stationed to give his whole attention to the line run- 
ning off clear, while another is employed to pour water con- 
tinually on the wood over which the line runs, to prevent ig- 
nition by friction. The angler knows that the sheepshead 
has this power of diving with the velocity of lightning; so 
have all fishes which are swift and wide compared to their 
length. In diving or darting upward, the swim-bladder is a 
great assistance, as it is found to be compressed while the 
fish is at the bottom, and expanded when the fish is on the 
surface of the water. Probably the salmon and the bluefish 
unite the greatest amount of muscular strength to the great- 
est power of propulsion. Other fishes of our coast, such as 
the Spanish mackerel, bonetta, cerus, and the horse mackerel, 
add to the muscularity of the salmon and bluetish the propul- 
sive power of the swordfish and the dolphin. The pectorals, 
ventrals, and anal fins assist the fish in maintaining its bal- 
ance or level position of body. In experimenting upon the 
use of fins, Professor Borelli, of Naples, ascertained that after 
clipping off the pectoral, ventral, and anal fins of fishes, all 
their motions became unsteady, and they reeled from right to 
left, and up and down, in such irregular manner as to prove 
that they were left at the mercy of their voracious neighbors 
of the deep. 
