“I don’t care to be shipmates with the stuff in that form many minutes longer than I have to be,” said Captain McGill, amid a general laugh, in which, perhaps, there was a little of the trace of the nervous strain which they had undergone.

At Mr. Lockyer’s request, the two Italians were questioned as to the whereabouts of Ferriss and Camberly, but they professed ignorance of where their employers were to be found. They were to have recovered their money by mail, they declared, but as a considerable sum was found on them, it was always supposed that they received some of their pay for their rascally attempt in advance.

“Well, gentlemen,” announced Captain McGill, a short time later, “the tests, both on the surface, semi-submerged, and submerged, have been perfectly satisfactory. Let us now head about and give these rascals over to justice. If their purpose was to ruin the Lockyer submarine and prevent her sale to the Government, they have failed. I shall report her at Washington as an unqualified success.”

“Thank you, sir!” said the inventor simply, and would have added more, but at this instant there came a sudden sharp hail from Tom Marlin, who had succeeded Midshipman Stark at the wheel.

“Something dead ahead, sir. I——”

Before he could complete the sentence there came a terrific shock. The submarine quivered from stem to stern under the stress of the blow. The party had to clutch at handrails and projections to avoid being thrown flat.

“We’ve struck something!” shouted Mr. Lockyer. A terrible fear burned in his eyes as a wild confusion of shouts and cries arose from below.

The submarine slewed round drunkenly, and a rasping sound rang from her steel plates. The inventor, cool-headed despite his alarm for his craft, sprang to the engine controls. Rapidly, he spun the telegraph indicator.

“Back! Full speed astern!”

Again came that bumping, rasping sensation. It was as if the little vessel had struck a reef or a submerged rock, although the chart showed none in that part of the ocean.