The Butterfly was all ready and waiting for its passengers when Grace and Sylvia, followed by the smiling and delighted Estralla, who was carrying Sylvia's cape and trying to act as much like a "rale grown-up lady's maid" as possible, came down to the long wharf.

Although it was December, there was little to remind anyone of winter. The air was soft and clear, the sun shone brightly, and only a little westerly breeze ruffled the blue waters of the harbor.

Negroes were at work on the wharf loading bales of cotton on a big ship. They were singing as they worked, and Sylvia resolved to remember the words of the song:

"De big bee flies high,
 De little bee makes de honey,
 De black man raise de cotton,
 An' de white man gets de money."

She repeated it over and then Grace sang it, with an amused laugh at her friend's interest in "nigger songs."

Mr. Fulton came to meet them and helped them on board the boat. As the Butterfly made its way out into the channel the little girls looked back at the long water-front, where lay many vessels from far-off ports. In the distance they could see the spire of St. Philip's, one of the historic churches of Charleston, and everywhere fluttered the palmetto flag.

Sylvia sat in the stern beside her father, and very soon the tiller was in her hand and she was shaping the boat's course toward the forts. Grace watched her admiringly.

"I believe you could steer in the dark," she declared.

"Of course she could if she had a compass and was familiar with the stars," said Mr. Fulton; and he called Grace's attention to the compass fastened securely near Sylvia's seat, and explained the rules of navigation.

"Is that the way the big ships know how to find their harbors?" asked Grace, when Mr. Fulton told her of the stars, and how the pilots set their course.

"Yes, and if Sylvia understood how to steer by the compass she could steer the Butterfly as well at night as she can now."

Sylvia looked at the compass with a new interest; she was sure that navigation would be a much more interesting study than grammar, and resolved to ask her father to teach her how to "box the compass."

There had been many changes at Fort Moultrie since Sylvia's last visit. A deep ditch had been dug between the fort and the sand-bars, and many workmen were busy in strengthening the defences, and Sylvia and Grace wondered why so many soldiers were stationed along the parapet.

Captain Carleton seemed very glad to welcome them, and sent a soldier to escort the girls to the officers' quarters, while Mr. Fulton went in search of Major Anderson. Sylvia wondered if she would have a chance to tell Mrs. Carleton that she had safely delivered the message.

Mrs. Carleton was in her pleasant sitting-room and declared that she had been wishing for company, and held up some strips of red and white bunting. "I am making a new flag for Fort Sumter," she said. "Perhaps you will help me sew on the stars, one for each State, you know."

"Is there one for South Carolina?" asked Grace, as Mrs. Carleton found two small thimbles, which she said she had used when she was no older than Sylvia, and showed the girls how to sew the white stars securely on the blue.

"Yes, indeed! One of the first stars on the flag was for South Carolina," replied Mrs. Carleton, "and this very fort was named for a defender of America's rights."

While Grace and Sylvia were so pleasantly occupied Estralla had wandered out, crossed the bridge which connected the officers' quarters with the fort, and now found herself near the landing-place, so that when Mrs. Carleton made the girls a cup of hot chocolate and looked about to give Estralla her share, the little colored girl was not to be seen.

"I'll call her," said Sylvia, and ran out on the veranda.

No response came to her calls, so she went down the steps and along the walk which led to the sand-bars, past the houses and barracks on Sullivan's island. No one was in sight whom she could ask if Estralla had passed that way. She climbed a small sand-hill covered with stunted little trees and looked about, but could see no trace of the little darky. It had not occurred to Sylvia that Estralla would go back to the fort.

"Oh, dear! I wonder where she can be," thought Sylvia, calling "Estralla! Estralla!" and sure that if she was within hearing Estralla would instantly appear. As Sylvia climbed over the sandy slope she saw here and there a small green vine with glossy leaves and a tiny yellow blossom, and resolved to gather a bunch to carry back to Mrs. Carleton. "When I give them to her I'll have a chance to say that Mr. Doane has the letter," she thought.

Wandering on in search of the flowers, she went further and further from the fort, up one sand slope and clown another, almost forgetting her search for Estralla, and finally deciding that it was time to go back to Mrs. Carleton.

"Probably Estralla is there before this, and they will be looking for me," she thought, and climbed another sandy slope, expecting to see the houses and barracks directly in front of her............