shades, from purpling amethyst to lapis lazuli and turquoise.

As they gazed spellbound, a strange thing occurred, a thing of such
wonder and beauty that Ted could but grasp his father's arm in silence.

Suddenly the peaks seemed to melt away, the white ice-pinnacles became
real turrets, houses and cathedrals appeared, and before them arose a
wonderful city of white marble, dream-like and shadowy, but beautiful as
Aladdin's palace in the "Arabian Nights." At last Ted could keep silent
no longer.

"What is it?" he cried, and the old chief answered, gravely:

"The City of the Dead," but his father said:

"A mirage, my boy. They are often seen in these regions, but you are
fortunate in seeing one of the finest I have ever witnessed."

"What is a mirage?" demanded Ted.

"An optical delusion," said his father, "and one I am sure I couldn't
explain so that you would understand it. The queer thing about a mirage
is that you usually see the very thing most unlikely to be found in that
particular locality. In the Sahara, men see flowers and trees and
fountains, and here on this glacier we see a splendid city."

"It certainly is queer. What makes glaciers, daddy?" Ted was even more
interested than usual in his father's talk because of Kalitan, whose dark
eyes never left Mr. Strong's face, and who seemed to drink in every word
of information as eagerly as a thirsty bird drinks water.