“But none of us ever manufactured dynamite,” answered Boston, with a grin.  “How long did they have you in Moro Castle, Doc?”

“Eight months,” snapped the doctor, his face clouding.  “Eight months in that rathole, with the loss of my property and practice—­all for devotion to science.  I was on the brink of the most important and beneficent discovery in explosives the world ever dreamed of.  Yes, sir, ’twould have made me famous and stopped all warfare.”

“The captain told me this morning that he’d heard from Marti,” said Boston, after an interval.  “Good news, he said, but that’s all I learned.  Maybe it’s from Gomez.  If he’ll only take hold again we can chase the Spanish off the island now.  Then we’ll put some of your stuff under Moro and lift it off the earth.”

In a short time, details of the craft ahead, hitherto hidden by distance, began to show.  There was no sign of life aboard; her spars were gone, with the exception of the foremast, broken at the hounds, and she seemed to be of about a thousand tons burden, colored a mixed brown and dingy gray, which, as they drew near, was shown as the action of iron rust on black and lead-colored paint.  Here and there were outlines of painted ports.  Under the stump of a shattered bowsprit projected from between bluff bows a weather-worn figurehead, representing the god of the sea.  Above on the bows were wooden-stocked anchors stowed inboard, and aft on the quarters were iron davits with blocks intact—­but no falls.  In a few of the dead-eyes in the channels could be seen frayed rope-yarns, rotten with age, and, with the stump of the foremast, the wooden stocks of the anchors, and the teak-wood rail, of a bleached gray color.  On the round stern, as they pulled under it, they spelled, in raised letters, flecked here and there with discolored gilt, the name “Neptune, of London.”  Unkempt and forsaken, she had come in from the mysterious sea to tell her story.

The climbed the channels, fastened the painter, and peered over the rail.  There was no one in sight, and they sprang down, finding themselves on a deck that was soft and spongy with time and weather.

“She’s an old tub,” said Boston, scanning the gray fabric fore and aft; “one of the first iron ships built, I should think.  They housed the crew under the t’gallant forecastle.  See the doors forward, there?  And she has a full-decked cabin—­that’s old style.  Hatches are all battened down, but I doubt if this tarpaulin holds water.”  He stepped on the main hatch, brought his weight on the ball of one foot, and turned around.  The canvas crumbled to threads, showing the wood beneath.  “Let’s go below.  If there were any Spaniards here they’d have shown themselves before this.”  The cabin doors were latched but not locked, and they opened them.

“Hold on,” said the doctor, “this cabin may have been closed for years, and generated poisonous gases.  Open that upper door, Boston.”