vise you to let me try it. If it has got a heart at all, I'll engage to send my spear right through the core of it; if it hasn't got a heart, I'll send it through the spot where its heart ought to be."
"Fire away, then, my boy," replied Jack with a laugh.
Peterkin immediately took the spear, poised it for a second or two above his head, then darted it like an arrow into the sea. Down it went straight into the centre of the green object, passed quite through it, and came up immediately afterwards, pure and unsullied, while the mysterious tail moved quietly as before!
"Now," said Peterkin, gravely, "that brute is a heartless monster; I'll have nothing more to do with it."
"I'm pretty sure now." said Jack, "that it is merely a phosphoric light; but I must say I'm puzzled at its staying always in that exact spot."
I also was much puzzled, and inclined to think with Jack that it must be phosphoric light; of which luminous appearance we had seen much while on our voyage to these seas. "But," said I, "there is nothing to hinder us from diving down to it, now that we are sure it is not a shark."
"True," returned Jack, stripping off his clothes; "I'll go down, Ralph, as I'm better at diving than you are. Now then, Peterkin, out o' the road!" Jack stepped forward, joined his hands above his head, bent over the rocks, and plunged into the sea. For a second or two the spray caused by his dive hid him from view, then the water became still, and we saw him swimming far down in the midst of the green object. Suddenly he sank below it, and vanished altogether from our sight!
