It moved easily and sank, but soon came up again.

A second time he grasped at it, and with both hands.
This time he caught it, and then lifted it out of the water into the boat.

These proceedings had been watched with the deepest interest; and now, as this curious floating thing made its appearance among them, they all crowded around it in eager excitement.
"It looks like a can of preserved meat," said the doctor.
"It certainly is a can," said Melick, "for it's made of metal; but as to preserved meat, I have my doubts." The article in question was made of metal and was cylindrical in shape.

It was soldered tight and evidently contained something.

It was about eighteen inches long and eight wide.