1872.] Meteoric Astronomy. 139 
was recognised. So we, who voyage with the earth on a 
wide path round the sun, must conclude—must be absolutely 
certain—that the two particular regions of circumsolar space 
which we traverse on August roth and November 13th are 
swarming with meteors. 
Yet we cannot for a moment imagine that two clouds of 
meteors are persistently present in these two regions. Each 
meteor is as surely acted upon by the sun’s mighty influence 
as this earth on which we live; and as surely as this earth, 
if brought to rest in any way, would be attracted towards 
the sun and fall upon his globe in about 643 days, so every 
member of a meteor-cloud placed where the August and 
November meteors are encountered would in about the same 
time fall upon the sun and be destroyed. 
It follows that the meteors must be in rapid motion, ona 
course keeping them clear of the sun’s orb; and, moreover, 
that the place of those which pass away from the region 
traversed by the earth must be more or less continuously 
supplied by arriving meteors. In other words, the August 
and November meteors must form a more or less complete 
zone or ring. The degree of completeness of either ring 
must correspond to the regularity of the recurrence of star- 
falls on the dates corresponding to either system. If it 
frequently chances that the display is intermitted, either for 
a few years or for many years in succession, the inference will 
be that greater or less gaps mar the completeness of the 
meteor zone; whereas, if no year passes without a display 
of meteors belonging to a system, we must infer as at least 
probable that the meteor system forms a complete ring. 
Thus judged, the November system appears to be very far 
from forming a continuous zone; since the display is often 
omitted for more than twenty years in succession, and is 
seldom repeated during more than four or five successive 
years. The August system, on the contrary, seldom fails to 
produce a display of greater or less splendour. 
So much may be regarded as demonstrated by the evidence 
already referred to. But to remove any doubt which may 
remain as to the justice of the inference that the August 
and November meteors are bodies travelling in a definite 
region of interplanetary space, there remains a test of a 
decisive nature. 
Since, according to the hypothesis, all the August meteors 
are travelling along the same orbital zone, they must cross 
the earth’s track on paths appreciably parallel, moving also 
with equal velocities. Now, regarding the earth with reference 
only to her orbital motion, we see that every meteor of the 
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