"If the reciprocators have fallen amongst that tangle they are hopelessly lost," remarked Lieutenant Palmer, indicating the position in which the wreck lay.
"That's what the grapnels fouled," added Gerald. "However, as the aeroplane sank its planes would doubtless cause it to describe a spiral-like motion. We may as well investigate all round the wreck. Have we backed sufficiently to turn?"
"I think so," replied Palmer, and ordering half-speed ahead, he thrust the helm hard over.
Seventy-five fathoms; only thirty feet from the bed of the sea. The searchlight was deflected till the lower sector of the ray was intercepted by the blunt nose of the submarine, while the light was of sufficient intensity to cast a faint luminosity over the wilderness of ooze that formed the floor of this marine desert.
"She's standing it all right," exclaimed Palmer, cheerfully. "Not a sign of a weak spot."
"Yes, it's safe enough, I think. Now, keep a sharp look-out."
The elevating planes were now turned to an almost horizontal position, barely sufficient to counteract the small reserve of buoyancy preserved by the submarine; and eddying in great circles the huge steel craft pursued her voyage of exploration.
The searchlight revealed a place of utter desolation. No trailing seaweed served to remind the men of the wonderful submarine pictures that artists love to depict; only a vast field of dark mud, surmounted by fathoms of practically opaque water.
Gerald feared for the success of their search in that maze of trackless ooze, for without a mark from which they might take their bearings the submarine must eventually wander far from the spot where she had descended. He glanced at his watch, it showed a quarter to five. That meant that in another twenty-five minutes the submarine must reach the surface, or Captain Brookes would imagine that some disaster had befallen them.
"How's the air below there?" sang out the officer in charge.
"All serene, sir; the mice are quite chirpy," replied one of the seamen.
"You had better be on the safe side and release a little more oxygen," continued Palmer. "Then stand by with the grapnel."
The grapnel was secured to the outside of the submarine, whence by means of an electric wire it could be lowered and engaged with the object to be salved. Its length was not sufficient to allow the possibility of fouling either the planes or the propeller.