the stores were being put on board, Arnold made a careful
examination of every part of the machinery, and then of the whole
vessel, in order to assure himself that everything was in perfect
order. This done, he gave his final instructions to those of the
little community who were left behind to await the arrival of the
steamer, and as the sun sank behind the western ridges of the island,
he went on board the _Ariel_ with Colston, took his place at the
wheel, and ordered the fan-wheels to be set in motion.

Colston was standing by the open door of the wheel-house as Arnold
communicated his order to the engine-room by pressing an electric
button, one of four in a little square of mahogany in front of the
wheel.

There was no vibration or grinding, as would have been the case in
starting a steamer, but only a soft whirring, humming sound, that
rose several degrees in pitch as the engines gained speed, and the
fan-wheels revolved faster and faster until they sang in the air, and
the _Ariel_ rose without a jar or a tremor from the ground, slowly at
first, and then more and more swiftly, until Colston saw the ground
sinking rapidly beneath him, and the island growing smaller and
smaller, until it looked like a little patch on the dark grey water
of the sea.

Away to the north and west he could see the innumerable islands of
the Hebrides, while to the east the huge mountainous mass of the
mainland of Scotland loomed dark upon the horizon.

When the barometer marked eight hundred feet above the sea-level, the
_Ariel_ passed through a stratum of light clouds, and on the upper
side of this the sun was still shining, shooting his almost level
rays across it as though over some illimitable sea of white fleecy
billows, whose crests were tipped with rosy, golden light.

Above the surface of this fairy sea rose north-eastward the black
mass of Ben More on the Island of Mull, and to the southward, the
lesser peaks of Jura and Islay.

While he was still wrapped in admiration of the strange beauty of
this, to him, marvellous scene, the _Ariel_ had risen to a thousand
feet, still almost in a vertical line from the island. Arnold now
pressed another button, and the stern propeller began to revolve
swiftly and noiselessly, and Colston saw the waves of the cloud-sea
begin to slip behind, although so smooth was the working of the
machinery, and the motion of the air-ship, that, but for this, he
could hardly have guessed that he was i