METEORS AND COMETS. 
195 
that have the sun as one focus, and extend far beyond 
[N’eptune’s orbit. Others move in curves that never 
bring them back to this system. Still others that 
have revolved in an orbit for some time seem drawn 
away by some force so that they never return. 
In times past comets have been an object of ap¬ 
prehension, being considered as precursors of war, 
pestilence, or famine. 
To get a correct idea of our little solar system, we 
must imagine ourselves off at a distance and behold 
the planets and satellites in 
their various motions : some 
moving with the slowness of 
an hour-hand on the dial of a 
watch, others like the minute- 
hand, while some of the satel¬ 
lites circle about their prima¬ 
ries quite like the second-hand. 
Observations of the star-field 
indicate that our whole solar Fig. 98—Comet III of 1862, 
system is moving. And on August 22d, showing 
n -XT T ]et of luinmous matter, 
whither? No one knows, but (Challis.) 
it is aiming toward a point in 
the constellation Hercules at the rate of four or five 
million miles a year. Does the whole system, too, 
have an orbit to travel about some immense central 
sun, parent of all ? 
Let us continue our journey on the wings of 
thought to the nearest star. As we recede, the 
smaller of our celestial group vanishes from sight, 
then the earth itself, and Jupiter; now nothing can 
