x THE STARRY HEAVENS 377 
forms and colours. They belong, however, to 
our Earth, and I must now pass on to ‘the 
heavenly bodies. 
THE MOON 
The Moon is the nearest, and being the 
nearest, appears to us, with the single excep- 
tion of the Sun, the largest, although it is in 
reality one of the smallest, of the heavenly 
bodies. Just as the Earth goes round the 
Sun, and the period of revolution constitutes 
a year, so the Moon goes round the Earth 
approximately in a period of one month. 
But while we turn on our axis every twenty- 
four hours, thus causing the alternation of 
light and darkness —day and night — the 
Moon takes a month to revolve on hers, so 
that she always presents the same, or very 
nearly the same, surface to us. 
Seeing her as we do, not like the Sun and 
Stars, by light of her own, but by the reflected 
light of the Sun, her form appears to change, 
because the side upon which the Sun shines 
_is not always that which we see. Hence the 
