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the watery vapour or other constituents of our atmosphereproduce. It would be of the darkest black even in fulldaylight. The glare of the Sun would be bounded by theexact limits of its disc, so that its coronal and other append-ages would be constantly visible. The stars, like minute butbrilliant diamonds, in number far greater than we behold,would, by day and by night alike, shine without twinkling inthe black vault of heaven. Interesting as all this might be,it would not upon the whole be very pleasant; and otherconsequences of the absence of a lunar atmosphere would bestill worse. The heat of the Sun would be unbearable duringthe long lunar day of about 354 hours’ duration, while theunmitigated cold of the succeeding night would be perhapseven more terrible.
In fact, Lord Ilosse has estimated that the change in thetemperature of the Moon ’s surface during each month exceeds500° Fahrenheit; and that under the vertical rays of theSun it is probably considerably higher than that of boiling-water. Those who have ascended to great altitudes, and havefelt the intensity of the Sun ’s heat in .a rarefied atmosphere,and then have been so unfortunate as to spend the nightunsheltered on some rocky elevation in the midst of Alpineglaciers, may have possibly gained thereby some very faintidea of the alternation of heat and cold upon the Moon .
The Earth, as seen from the Moon , would of course, monthby month, go through phases complementary to those whichthe Moon exhibits to us. Full Earth would take place whenwe see New Moon , and vice versa ; and the sight would indeedbe glorious. Moreover, as the Moon always turns very nearlythe same face to the Earth , the latter would seem to a lunarobserver to be nearly fixed in the heavens ; while the outlinesof continents and oceans would give a pleasing variety to itsdisc, which would appear nearly 3§ times as broad, and morethan 13 times as large in area, as that which the Moon showsto us. We must not, however, pursue such hypothetical ob-servations any further. It will be more profitable to turnto a few remaining points of interest connected with thosewhich can be made from our own standpoint on the Earth ,