The pressure of the atmosphere as taken by an aneroid barometer
confirmed his observation, but as we were ignorant of its average
density it could not give us any certain indication of our height. Far
beneath us an ideal world of clouds hid the surface from our view. We
seemed to be floating above a range of snowy Alps, their dusky valleys
filled with glaciers, and their sovereign peaks glittering in the sun
like diamonds. As we descended in a long slant, their dazzling summits
rose to meet us, and the infinite play of light and shade became more
and more beautiful. The gliding car threw a distinct shadow which
travelled along the white screen, and equally to our surprise and
delight became fringed with coloured circles resembling rainbows.

"It is a good omen!" cried Miss Carmichael.

"Humph!" responded the professor, shaking his head but smiling
good-humouredly; "that is a mere superstition I'm afraid. It is simply
an optical effect, a variety of the phenomenon called 'anthelia,' like
Ulloa's Circle and the famous 'Spectre of the Brocken.'"

"Explain it how you will," rejoined Miss Carmichael, "to me it is an
emblem of hope. It cheers my heart."

"I am very glad to hear it, and I should be very sorry to crush your
hopes," said Gazen pleasantly. "We can sometimes derive moral
encouragement and profit from external phenomena. A rainbow in the midst
of a storm is a cheering sight. I daresay there is a reasonable basis,
too, for certain superstitions. St. Elmo's Fire may, for instance, from
natural causes, be a sign of good weather, only there is nothing
supernatural about it."