7 6 THE POPULAR SCIENCE MONTHLY. 



Porpoises bent upon voyages of their own pass us at intervals. 

 At each turn in the water we see their huge fins and shining, con- 

 vex bodies. The porpoise describes a graceful, undulatory line in 

 its course through the water ; now appearing at the surface and 

 immediately diving below it, showing itself only as it rounds the 

 crest of each wave. When a number rise together in line, their 

 dorsal fins and backs alone being visible, you are reminded of a 

 great saw with huge, incurved teeth. Here, again, are others .ap- 

 parently at play. How they lash the water into spray with their 

 powerful tails ! Now one shoots like an arrow into the air ; an- 

 other jumps, and clearing the water for several feet, enters it 

 again with a plunge. This may be anything but play, however. 

 A whale or some other enemy is perhaps giving them chase, and 

 they are fleeing for their lives. 



We saw several whales during this voyage, and on one even- 

 ing two crossed our bows. They swam side by side, rolling along 

 at an easy gait, much like that of the porpoise, and spouting a jet 

 of spray as they came to the surface to breathe. 



At another time a very large school of porpoises was seen ad- 

 vancing toward our vessel. There must have been several hun- 

 dred of them. They formed a long, not very deep line, swimming 

 in several squads of fifty or more each, and crossed our course 

 without altering theirs. Some passed by the stem or bow, or with 

 a plunge shot under the vessel as if it were a plank. Both dol- 

 phins and porpoises like to race with a ship, although it costs many 

 their lives. You can see their brown, spotted bodies and blunt 

 noses as with great speed they shoot to this and that side of the 

 cutwater. The faster the ship goes the greater seems to be the 

 sport. The porpoise is little more than a powerfully muscular 

 tail, developed at the expense of the rest of the body. Most sail- 

 ing craft carry a spear or harpoon, for the sailors not only like 

 the excitement of taking these animals, but also find in their flesh 

 a welcome variety to the monotonous ship fare. 



One morning, as I stood with the captain on the forecastle 

 deck, he attaching his harpoon line as I watched the porpoises, I 

 saw a large loggerhead turtle under the bow, his brown back be- 

 ing barely under water. He appeared to be asleep, but in a mo- 

 ment the vessel struck him, and down he slowly paddled out of 

 sight. The spear did not happen to be in readiness, so that our 

 turtle soup that day was a strictly Barmecide dish. 



The number of small invertebrate animals which come to the 

 surface on calm evenings is quite astonishing. Once in May, 

 while in the vicinity of the Gulf Stream, near the Florida coast, 

 there appeared regularly at about four o'clock in the afternoon 

 countless swarms of a brown jellyfish or medusa " sea thimbles," 

 as sailors call all animals of this class and this species (Linerges) 



