248 A, C, Twining on Meteoric Rings as 
mediately to the earth’s conjunction with the ring, we may in- 
vestigate the orbital effects upon all meteors within a cylinder 
extending to the utmost appreciable extent of immediate or ex- 
traordinary terrestrial influence considering the relative — 
equal and parallel to an axis—as it may be termed—of the cylin- 
der passing through the earth’s centre. (B) 
Let then the cylinder of influence, so to call it, be represented 
in figure 2 by its bound- 
ing curves and surfaces 
upon the ecliptic, as ow 
qpv-and upon a em of 
the meteoric ring, as 
p'p u, and the contained 
lines 00, uu, pp, 
which also represent the 
lel relative lines of 
approach of the meteors 
0, u, p and v to the earth, 
or the asymptotes of their 
orbits. The axis is Zz 
The plane E mt. is the : 
sameasdesignated bythe 
same letters in figure 1, 
and oospq His a section 
by that plane, and wsv E 
represent the asymptotes 
of two orbits touching a 
circle or section of any 
definite extent from the 
earth’s centre E, in the 
plane Emi. 
Now the meteors m 
symptotes, pairing with 
mm and rr respectively, 
to incline towards on a 
anotber—as 00! and p py hich al 
| ¥: avely, and ok aay to the othite of 0 “oan 
Now if’ section mEr and the asymptotes mm, rr, Were 
