“Full speed ahead,” was Captain Templeton’s signal to the engine room.

“Take a look below, Frank,” said Jack to his first officer.

“Aye, aye, sir.”

Frank descended a manhole in the deck.  He closed the cover and secured it behind him.  At the foot of the ladder was a locked door.  As it opened, came a pressure on Frank’s ear drums like the air-lock of a caisson.  Frank threaded his way amid pumps and feed water heaters and descended still further to the furnace level.

Twenty-five knots—­twenty-eight land miles an hour—­was the speed of the Plymouth at that moment.  It was good going.

Below, instead of dust, heat, the clatter of shovels, grimy, sweating fireman, such as the thought of the furnace room of a ship of war calls to the mind of the landsman, a watertender stood calmly watching the glow of oil jets feeding the furnace fire.  Now and then he cast an eye to the gauge glasses.  The vibration of the hull and the hum of the blower were the only sounds below.

For the motive power of the Plymouth was not furnished by coal.  Rather, it was oil—­crude petroleum—­that drove the vessel along.  And though oil has its advantage over coal, it has its disadvantages as well.  It was Frank’s first experience aboard an oil-burner, and he had not become used to it yet.  He smelled oil in the smoke from the funnels, he breathed it from the oil range in the galley.  His clothes gathered it from stanchions and rails.

The water tanks were flavored with the seepage from neighboring compartments.  Frank drank petroleum in the water and tasted it in the soup.  The butter, he thought, tasted like some queer vaseline.  But Frank knew that eventually he would get used to it.

“How’s she heading?” Frank asked of the chief engineer.

“All right, sir,” was the reply.  “Everything perfectly trim.  I can get more speed if necessary.”

Frank smiled.

“Let’s hope it won’t be necessary, chief,” he replied.

He inspected the room closely for some moments, then returned to the bridge and reported to Captain Templeton.

The sea was rough, but nevertheless the speed of the flotilla was not slackened.  It was the desire of Captain Petlow, in charge of the destroyer fleet, to convoy the transports beyond the danger point at the earliest possible moment.

The Plymouth lurched up on top of a crest, then dived head-first into the trough.  On the bridge the heave and pitch of the vessel was felt subconsciously, but the eyes and minds of the officers were busied with other things.  At every touch of the helm the vessel vibrated heavily.

Eight bells struck.

“Twelve o’clock,” said Frank.  “Time to eat.”

The bridge was turned over to the second officer, and Frank and Jack went below.

“Eat is right, Frank,” said Jack as they sat down.  “We can’t dine in this weather.”

It was true.  The rolling boards, well enough for easy weather, proved a mockery in a sea like the one that raged now.  Butter balls, meat and vegetables shot from plates and went sailing about.  It was necessary to drink soup from teacups and such solid foods as Jack and Frank put into their stomachs was only what they succeeded in grabbing as they leaped about on the table.