“Just the same speed, Hal?” the young captain asked.
“Hasn’t changed a single revolution per minute,” Hastings answered, briefly.
With his watch on the table before him, and employing the scale rule and dividers, the young submarine skipper placed a new dot on the chart.
“Something ought to be happening in three quarters of an hour,” Benson remarked, with a chuckle, to Mr. Pollard.
Less than half an hour later the young submarine skipper climbed up into the conning tower beside Eph.
“Same old straight course, eh, lad?” asked Jack quietly.
“You know it,” retorted Eph.
“Then we’re where we ought to be,” responded Jack Benson, bending forward. With his right hand on the speed control he shut off speed.
“Now, just sit where you are, Eph, until I come up again,” advised the young commander.
“Going to the surface?” demanded Somers, with interest.
“Pretty close,” nodded Benson.
Calling Mr. Pollard to his aid, Jack began to operate the machinery that admitted compressed air to the water tanks, expelling the water gradually from those same tanks. This was the means by which the submarine boat rose to the surface. All the time that he was doing this, Jack Benson kept his keen glance on the submersion gauge. At last he stopped.
“How is it up there, Eph?” he called, pleasantly.
“Why, of course there’s a lot of good daylight filtering down through the water now,” Somers admitted.
Captain Jack went nimbly up the spiral stairway. Now, he had still another piece of apparatus to call into play. This affair is known to naval men as the periscope.
In effect, the periscope is a device which in the main is like a pipe; it can be pushed up through the top of the conning tower, through a special, water-proof cylinder, until the top of the periscope is a foot, or less, above the surface of the water.
The top of this instrument is fitted with lenses and mirrors. Down through the shaft of the periscope are other mirrors, which pass along any image reflected on the uppermost mirror of all. At the bottom of the periscope is the last mirror of the series, and, opening in upon this, there is an eyepiece fitted with a lens.
As Captain Jack Benson applied his right eye to the eyepiece he was able to see anything above the surface of the water that lay in any direction that the periscope was pointing.
“Right opposite Spruce Beach, as the chart showed!” chuckled the young commander. Under the magnifying effect of the eyepiece lens Benson could see the beach, the flag-bedecked hotels, and the moving masses of people on the shore. Yet, all this time, he was out at sea, more than a mile from the beach. The periscope itself, if seen from a boat an eighth of a mile away, would undoubtedly have been taken for a floating bottle.
“Let me have a peep,” demanded Somers.