"He understood, he explained, that we lived on the surface of the earth, that our air and sea were outside the globe; the latter part, indeed, he already knew from his astronomical specialists. He was very anxious to have more detailed information of what he called this extraordinary state of affairs, for from the solidity of the earth there had always been a disposition to regard it as uninhabitable. He endeavoured first to ascertain the extremes of temperature to which we earth beings were exposed, and he was deeply interested by my descriptive treatment of clouds and rain. His imagination was assisted by the fact that the lunar atmosphere in the outer galleries of the night side is not infrequently very foggy. He seemed inclined to marvel that we did not find the sunlight too intense for our eyes, and was interested in my attempt to explain that the sky was tempered to a bluish color through the refraction of the air, though I doubt if he clearly understood that. I explained how the iris of the human eyes can contract the pupil and save the delicate internal structure from the excess of sunlight, and was allowed to approach within a few feet of the Presence in order that this structure might be seen. This led to a comparison of the lunar and terrestrial eyes. The former is not only excessively sensitive to such light as men can see, but it can also see heat, and every difference in temperature within the moon renders objects visible to it.
"The iris was quite a new organ to the Grand Lunar. For a time he amused himself by flashing his rays into my face and watching my pupils con-
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