This very curious phenomenon, which was remarked by M. Monge, one of the
French savans belonging to the institute of Cairo, in the hot and sandy
desert between Alexandria and that city, is described by him as
resulting from an inverted image of the cerulean sky intermixed with the
ground scenery, the neighboring villages appearing to be surrounded with
a most beautiful sheet of water, and to exist, like islands, in its
liquid expanse, tantalizing the eye by an unfaithful representation of
what the thirsty traveler earnestly desires.
Doctor Clarke, in his interesting travels, introduces the following
animated description of this phenomenon. “Here [at the village of Utko]
we procured asses for our party, and, setting out for Rosetta, began to
recross the desert, appearing like an ocean of sand, but flatter and
firmer as to its surface, than before. The Arabs, uttering their harsh,
guttural language, ran chattering by the side of our asses; until some
of them calling out _‘Raschid!’_ we perceived its domes and turrets,
apparently upon the opposite side of an immense lake or sea, that
covered all the intervening space between us and the city. Not having in
my own mind, at the time, any doubt as to the certainty of its being
water, and seeing the tall minarets and buildings of Rosetta, with all
its groves of dates and sycamores, as perfectly reflected by it as by a
mirror, insomuch that even the minutest detail of the architecture and
of the trees might have been thence delineated, I applied to the Arabs
to be informed in what manner we were to pass the water. Our
interpreter, although a Greek, and therefore likely to have been
informed of such a phenomenon, was as fully convinced as any of us, that
we were drawing near to the water’s edge, and became indignant, when the
Arabs maintained, that within an hour we should reach Rosetta, by
crossing the sands in the direct line we then pursued, and that there
was no water. ‘What!’ said he, giving way to his impatience, ‘do you
suppose me an idiot, to be persuaded contrary to the evidence of my
senses?’ The Arabs, smiling, soon pacified him, and completely
astonished the whole party, by desiring us to look back at the desert we
had already passed, where we beheld a precisely similar appearance. It
was, in fact, _the mirage_, a prodigy to which all of us were then
strangers, although it afterward became more familiar. Yet upon no
future occasion did we ever behold this extraordinary illusion so
marvelously displayed. The view of it afforded us ideas of the horrible
despondency to which travelers must sometimes be exposed, who, in
traversing the interminable desert, destitute of water, and perishing
with thirst, have sometimes this deceitful prospect before their eyes.”
This appearance is often seen, when the sun shines, upon the extensive
flat sand upon the shores of the Bristol channel, in Somersetshire, and
probably on the sea-shore in other parts of England.