•jy'^ Ho^iE Nature-Study Course. 



just as cold as space which is estimated at 250 degrees below zero, while the part 

 of the moon in the sunshine would receive the full force of the heat of the sun and 

 become 500 degrees hot. There would, therefore, be about 750 degrees difference 

 between night and day or between shadow and sunshine. It is difficult for us to 

 realize how much we owe to this blanket of air which surrounds our earth for 

 the protection it affords us from both heat and cold. 



As sound is carried entirely by means of wave motion in the air there could be 

 no sound upon the moon. If we could manage to shout or to fire a cannon on the 

 moon still there would be no sound. Great mountains might fall upon the moon 

 but the silence would remain unbroken. 



As there are no oceans, streams or lakes or water of any kind on the moon there 

 can be no rain nor snow nor clouds there. Our own rocks are broken in pieces 

 by means of water which filters into the cracks and then expands by freezing and 

 breaks the rock, or the rocks are worn away by streams dashing against them. 

 But on the moon there can be no action of either wind or water upon the rocks 

 thus the mountains there would remain unchanged. The only force which could 

 disturb the surface of the moon would be the meteors or shooting stars. There 

 are many of these bits of worlds whirling along through space and the reason we 

 know so little of the seven million meteorites which Professor Newton says we 

 encounter every twenty-four hours is because when they strike our atmosphere the 

 friction sets them afire and they burn before reaching the earth. If they are small 

 we see only a streak of light across the sky and we say, " there is a shooting star," 

 while if they are large, " there is a meteor ;" but the moon having no atmosphere 

 receives the full fores of all the meteors which it encounters, and undoubtedly is 

 often injured by such collisions. 



References. — " The Moon," Nasmyth & Carpenter (the lessons of 

 this leaflet have been based upon this beautiful and interesting volume, 

 which is too expensive for ordinary school libraries, but may be found 

 in larger libraries); " Starland," Ball; "Stories of Starland," Mary 

 Proctor ; " Familiar Talks on Astronomy," Parker. 



The Lady in tJte Moon. 



