Proctor's Astronomical Lectures. 



81 



2' v l as another will work it in another way, it 

 Is ^7 comparing the two that you are led 

 to t link that there was a change. I must 

 Xneuiiou thai llae moon is unlike our earth in its general 

 conditions, in nearly all the important respects which 

 we assoc-iate with it. The total day lasts 29J of our days. 

 While the day lasts so long, the year is very much 

 less than ours. It is only 346 of our days. It 

 may seem rather strange that as the moon is a planet, 

 in reality, that therelore it has a year less than ours ; 

 tbat it ought to be the same as ours. But there is a 

 Blow tiltiug of the moon, corresponding to the preces- 

 sion of the equinoxes. That shortens our year by a few 

 hours, but in tue moon it shortens it for a few days. 



AN EARTH-LIGHT SCENE ON THE ITOO-T8 SURFACE. 



Tiiero you have a picture of tho lunar cr; ter Coper- 

 Die is as it minht appear to the inhabitants of tho moon. 

 It \vus drawn by James Hamilton of PniluaeU 'iia. You 

 will notice the earth suspended as a luoon to the 

 inhabitants of the moon. The earth id, according to no 

 conception, too small. It would appear to them as 

 a moon 13J times as large as the moon appears 

 to us. We will have a picture of the lunar crater Tycho, 

 from which those great radiations extend, which give 

 the moon the nppe;irance of an orange, and which 

 caused Dr. Holmes to linen it to a peeled orange. [Laugh- 

 ter.] 



Always In these lunar pictures, these Imaginary ones, 

 the mistake is made of introducing signs of weather 

 ing which we know to lie due to the effect of rain, or more 

 remarkably to tho effects of snow. We know that th 

 peaks of our mountains are becoming more and mort 

 worn down by the glaciers. But as there is no water in 

 the moon, there cannot be any rain or any- snow, and 

 therefore none of these effects of denudation can he 

 seen. 



Hire is an ideal picture of the Apennines. You will 



Liotice tiiu peculiar slope of them. A?i in we have tho 

 erroneous signs of weathering. You never see mountains 

 like those except where snow ia. 



IDEAL VIEW OF MOUNTAIN SCENERY IK 



In the picture you are supposed to be 

 the Apennines from Aristarchus. 



MOON. 



looking 



TJNLIGHT SCENE ON MOON'S SURFACE: EARTH SHOWING 

 ITS DARK SIDE. 



