THE MOOff. 



To those who inhabit the central part of the hemisphere presented 

 to us, the earth would appear stationary in the zenith, and would 

 never leave it, never rising nor setting, nor in any degree 

 changing its position in relation to the zenith or horizon. To 

 those who inhabit places intermediate between the central part 

 of that hemisphere and those places which are at the edge of the 

 moon's disk, the earth would appear at a fixed and invariable 

 distance from the zenith, and also at a fixed and invariable 

 azimuth, the distance from the zenith being everywhere equal to 

 the distance of the observer from the middle point of the hemi- 

 sphere presented to the earth. To an observer at any of the 

 places which are at the edge of the lunar disk, the earth would 

 appear perpetually in a fixed direction on the horizon. 



The earth shone upon by the sun would appear as the moon 

 does to us; but with a disk having an apparent diameter 

 greater than that of the moon in the ratio of 79 to 21, and an 

 apparent superficial magnitude about fourteen times greater, and 

 it would consequently have a proportionately illuminating power. 



Earth light at the moon would, in fine, be about fourteen 

 times more intense than moonlight at the earth. The earth 

 would go through the same phases and complete the series of 

 them in the same period as that which regulates the succession 

 of the lunar phases, but the corresponding phases would be 

 separated by the interval of half a month. When the moon is 

 full to the earth, the earth is new to the moon, and vice versa : 

 when the moon is a crescent, the earth is gibbous, and vice versd. 



17. The features of light and shade would not, as on the moon, 

 be all permanent and invariable. So far as they would arise from 

 the clouds floating in the terrestrial atmosphere they would be 

 variable. Nevertheless, their arrangement would have a certain 

 relation to the equator, owing to the effect of the prevailing atmo- 

 spheric currents parallel to the line. This cause would produce 

 streaks of light and shade, the general direction of which would 

 be at right angles to the earth's axis, and the appearance of which 

 would be in all respects similar to the BELTS which are observed upon 

 some of the planets, and which are ascribed to a like physical cause. 



18. Through the openings of the clouds the permanent geogra- 

 phical features of the surface of the earth would be apparent, and 

 would probably exhibit a variety of tints according to the prevail- 

 ing characters of the soil, as is observed to be the case with the 

 planet Mars even at an immensely greater distance. The rotation 

 of the earth upon its axis would be . distinctly observed and its 

 time ascertained. The continents and seas would disappear in 

 succession at one side and reappear at the other, passing across 

 the disk of the earth as carried round by the diurnal rotation. 



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