SUNBEAMS AND THEIR WORK. 27 
ripples of the sea, or making bows of coloured light 
on the waterfall? Is not the sunbeam so dear to us 
that it has become a household word for all that is 
merry and gay? and when we want to describe the 
dearest, busiest little sprite among us, who wakes a 
smile on all faces wherever she goes, do we not call 
her the " sunbeam of the house " ? 
And yet how little even the wisest among us know 
about the nature and work of these bright messengers 
of the sun as they dart across space ! 
Did you ever wake quite early in the morning, 
when it was pitch-dark and you could see nothing, 
not even your own hand; and then lie watching as 
time went on till the light came gradually creeping in 
at the window? If you have done this you will have 
noticed that you can at first only just distinguish the 
dim outline of the furniture ; then you can tell the dif- 
ference between the white cloth on the table and the 
dark wardrobe beside it ; then by degrees all the small- 
er details, the handles of the drawer, the pattern on 
the wall, and the different colours of all the objects in 
the room become clearer and clearer till at last you see 
all distinctly in broad daylight. 
What has been happening here ? and why have the 
things in the room become visible by such slow de- 
grees? We say that the sun is rising, but we know 
very well that it is not the sun which moves, but that 
our earth has been turning slowly round, and bringing 
the little spot on which we live face to face with the 
great fiery ball, so that his beams can fall upon us. 
Take a small globe, and stick a piece of black 
plaster over the United States, then let a lighted lamp 
