The skipper nodded again.

“Is there anything to be done?”

“Nothing except to make all the time we can and keep a weather eye aloft and abroad.  Watch your sails and trim them for every breath of air.  Jockey her.  Now is your time to see what can be done when there is little wind to be had.”

Harriet was getting practical experience in sailing a boat such as falls to few novices, but she took to the work like one who had long been used to the sea and its varying moods.  Under her skilful manipulation the “Sister Sue” was making fairly good headway, though nothing like what she had done on the outward voyage, for the wind was dying out, becoming more fitful, shifting from one point of the compass to another.

“When the wind moves opposite to the direction of the hands of a clock—­what seamen call ’against the clock’—­look out for foul weather,” the captain informed her.

“That is the way it is going now, isn’t it?”

“Yes.”

“I hope we shall have enough to take us home.”

“We may have too much.”  Once more the skipper studied the horizon to the northeast.  That he was not pleased with his observation Harriet was confident.  Again he took a long look at the barometer, glanced at the compass to see that she was on her course, then, thrusting his hands into his pockets, studied the rigging overhead.

“We aren’t making much headway, are we?” questioned Miss Elting.

“None at all,” was the, to her, surprising reply; “we’re in a dead calm now.”

The waves had taken on an oily appearance and there were no longer white crests on the rollers.  The “Sister Sue” rolled and plunged in a sickening way, the boom swinging from side to side.  All hands were in the cockpit or cabin, however, so that there was no danger of their being hit by the swinging boom.  In the cabin was heard a series of groans more agonized than before.  The guardian had recovered in a measure, though they observed that she was very pale.  The fresh air outside revived her somewhat.

“I wish you to tell me frankly if there is any danger?” she demanded.

“Not yet,” was the skipper’s evasive answer.

“Meaning that there may be later?”

“We may be late getting home,” he replied.  “I can’t say any more than that now.  Ugh!”

Harriet Burrell saw him gazing off to the northeast.  She followed the direction of his glance, and saw a purplish haze hanging heavily on the horizon.  As she gazed the purple haze seemed to grow darker and to increase in size.  The sight disturbed her, though she did not know why.  The sea now made little noise.  A flock of seagulls could be plainly heard honking high overhead, and a chattering flock of stormy petrels soared down, coming to rest on the water in the wake of the sloop.

“I’ll take in the jibs.  Mind your wheel.  We are in for a blow,” announced the skipper.

CHAPTER XXII