"Not sharks, eh? Horse-mackerel, I guess, or sturgeon," rapidly conjectured Harry.
"Great Scott! No, old man—threshers, as you're a sinner!" concluded Walter, decisively. "And there's a whole school of 'em. Look out for your lines!"
But even as the truth flashed upon him his caution was too late, for one of the threshers dashed alongside, sweeping it clear of lines and leaving them afar off, as the school proceeded to gambol in a new direction.
"This is interesting, but I don't think it will pay as well as bluefish," remarked Walter; and even as he spoke another line on the opposite side went with a snap, as the fish scurried off with a vindictive splash of his mighty caudal appendage.
"Let's make it pay!" ejaculated Harry, quick to resolve.
"Capital idea, my boy! Will you kindly elucidate your proposition?" inquired Walter, as he ruefully gathered in some wreckage of bluefishing gear.
"Why," said Harry, "let's make over to Brentons Reef Light-ship, and see if we can't get some shark hooks and bait from the crew, and capture one of the beggars."
"We might try it," said Walter, contemplatively. "Those piratical splashers certainly have assumed too much audacity to suit my equanimity, and they deserve to be punished. Well, get her around, and we'll run over to the light-ship and see."
It was always the quick brain of Harry that planned such expeditions, and as the Katie made good time on her course he eagerly pictured the heroic effect of capturing a thresher and towing it to port. Walter Clay, always willing for any sort of adventure that was not too reckless for a fair chance of safety, and warranted not to get "rattled," but preserve his good-nature and presence of mind under all circumstances, carefully arranged the details of the proposed venture. The men on the light-ship happened to have just such gear as was required for the purpose, and willingly lent it, including a cable's-length (120 fathoms) of stanch half-inch hemp line coiled in a tub, and a big shark-hook with several feet of chain, as well as some chunks of salt pork for bait. They likewise informed the boys that the threshers were probably the same school that had been reported the day before as greatly interfering with the fishermen off on Montauk Shoal.
Specimens of the genuine thresher-shark indeed these creatures were—those Alopias vulpes, or sea-foxes, the dorsal lobes of whose tails are nearly as long as the rest of their bodies, and are used in splashing the surface of the water to aid in securing their prey of small fish. Exceedingly grotesque in appearance they seemed sometimes, the upper lobe of the long tail curving upwards and resembling in form the blade of a scythe. One of the men on the light-ship said he had always heard them called "swingle-tails," and also volunteered the information that the biggest he had ever seen was one caught at Marion, Massachusetts, in November, 1864, which measured thirteen feet long and weighed about 400 pounds. Some people believed that they attacked whales, but he had seen them all up and down the North Atlantic coast, as well as in the Mediterranean and off California, and "in all his going to sea he had never found a whale yet that wouldn't laugh at a thresher." The most damage they did was to fishermen's nets and lines.