"No; you could hardly lose her so easily," he answered. "Did you ever try holding an object behind a water-bottle or a gold-fish jar? There is a place near the edge of the jar where a thing cannot be seen, though the glass and water are perfectly transparent. The rays of light from the object are bent around, through the glass and water, away from the eyes of the observer. It was like that with the Moon when she disappeared. She was really drawing out from the Earth all the time. Finally, when her light passed beyond the atmosphere altogether, she became suddenly visible in a different place and shining with another colour. What we see now is the real Moon in her true place. The other appearances were all tricks of refraction."
"But when I had turned away," I explained, "there came a thin rim of bright light on the other side of the Earth, and a gradually appearing umbrella shape there too."
"Ah, then you steered far enough out of your course to see part of the illuminated surface of the Earth. That was the real danger light. And if it began to assume the umbrella shape, detached from the Earth, that was due to atmospheric refraction of sunlight. This great shadow we are travelling in has an illuminated core, which we shall encounter when we have proceeded a little further. I tell you of it now, so it may not give you another shock. Have you ever noticed the small bright spot which illuminates the centre of the shadow cast by a glass of water? That is partly the same as the core of light which exists in the heart of this shadow. Rays from the sun, passing on all sides of the Earth, are refracted through the atmosphere and bent inward. You must have steered over into some of these rays just now, and then turned back from them. Somewhat farther on all these refracted rays will meet at a common centre, which they will illuminate, and we shall have an oasis of rainbow-tinged sunlight in this great desert of shadow. The sun will then appear to us to be an enormous circle of dull light entirely surrounding the Earth."
"I don't fancy running into that at all," said I. "Can't we avoid it by steering out?"
"Avoid it!" exclaimed the doctor. "We must investigate it, and photograph the peculiar appearance of the sun. Light seems to have more terrors for you than anything else just now. You must get over your rush-and-do tendency; you must stifle your emotions and impulses, and learn to think of things in a more calm and scientific manner."
"But that is not so easy for me, Doctor. Whenever I am left alone, a feeling of dread possesses me. I am used to having many people, bustling noises, and confused movement all about me. The silence of Space stifles me, and the loneliness of the ether oppresses and overcomes me strangely."
"I prescribe a change of air for you," answered the doctor. "You will do better in a rarer atmosphere. Let us send what we have been breathing back to Whiting, and make a new one to suit ourselves."