e the mortars, in play, jarring the earth with
their heavy thunders. The shells were sweeping in graceful curves
through the air. Upon our left hand, the Benton and Carondelet were
covering themselves with white clouds, which slowly floated away over
the woodlands, fragrant with the early buds and blossoms of spring. The
Rebel batteries below us were flaming and smoking. Solid shot screamed
past us, shells exploded above us. Away beyond the island, beyond the
dark-green of the forest, rose the cloud of another bombardment, where
Commodore Hollins was vainly endeavoring to drive Colonel Plummer from
his position. So the prayer was mingled with the deep, wild thunders of
the cannonade.

A light fog, like a thin veil, lay along the river. After service, we
saw that strange and peculiar optical illusion called _mirage_, so often
seen in deserts, where the thirsty traveller beholds lakes, and shady
places, cities, towns, and ships. I was looking up stream, and saw,
sweeping round the wooded point of land, something afloat. A boat or
floating battery it seemed to be. There were chimneys, a flagstaff, a
porthole. It was seemingly two hundred feet long, coming broadside
towards us.

"Captain Thompson, see there!"

He looked at it, and jumped upon the pilot-house, scanned it over and
over. The other officers raised their glasses.

"It looks like a floating battery!" said one.

"There is a porthole, certainly!" said another.

It came nearer. Its proportions increased.

"Pilot, put on steam! Head her up stream!" said Captain Thompson.

"Lieutenant, beat to quarters! Light up the magazine! We will see what
she is made of."

There was activity on deck. The guns were run out, shot and shell were
brought up. The boat moved up stream. Broadside upon us came the unknown
craft.

Suddenly the illusion vanished. The monster three hundred feet long,
changed to an old coal-barge. The chimneys became two timbers, the
flagstaff a small stick of firewood. The fog, the currents of air, had
produced the transformation. We had a hearty laugh over our preparations
for an encounter with the enemy in our rear. It was an enemy more
quickly disposed of than the one in front.

The Rebels in the upper battery waved a white flag. The firing ceased.
Commodore Foote sent Lieutenant Bishop down with a tug and a white flag
flying, to see what it meant. He approached the battery.

"Are we to understand that you wish to communicate with us?" he a