250 A. C. Twining on Meteoric Rings as 
f 
v2 
a= 3923. And if a and y are the transverse and the conju- 
gate axes respectively they are measured by the formulas 
422 2 
x => y=2(-— ree :—therefore x is 270, and y 8112. Con- 
sequently the angle of the asymptotes is 8° 49’, which is also the 
angular deviation of m and 7 compared together in their lines 
of motion taken at their apsides : 
It appears therefore that the variations of radiant position, for 
the meteors of August 9th-11th cannot exceed 3° 49’, and may, i 
the comparison of extremes, approach to that amount. It is obvi- 
ous that the axis itself changes place continually in a circle of 
latitude in consequence of the terrestrial rotation,—so that to 
the view of a single observer the hour of day is productive of 
a change of the radiant’s position, although observation may nt 
ordinarily be close enough to detect it. 
If we enquire into the general effect upon the mass of meteors 
at great distances from the earth, we have simply to observe that 
2 
3 , inasmuch as L varies as the squares of 
: L—4z 
the areas simultaneously described, and therefore as p? or y’; and 
is also equal to the latter varies as y?,—that is to say « 18 co 
stant. But yis equal to p. Consequently the small angular deflec- 
tion of asymptotes will vary in the aed ratio of p. _ If half the 
above distance, or 4056 miles, is taken unity, and D is any other 
distance in any axial plane, the average effect upon all sai 
in that plane and to that extent will be, in minutes, 229’ pe ’ 
80 that for half a million of miles extending on either side of ie 
earth the average deflection would be 9’. But for the entire el 
cle the same would be approximately 229’ Ss or for the entre 
cylinder of one million of miles diameter, the average perm® 
nent deflection would be 32’, which is the average estimated 10 
all directions taken in the aggregate. But if estimated in a 5! 
sg direction only the same average would sink to only 2y. 
‘A ese quantities are meant to give some idea of the effect up?? 
191,003, and z becomes known by the equation 22+ 2 =p? or 
in the formula x = 
Tge masses or assemblages of meteors; which, howeve?, after 
ml, form only small fractions of the entire ring. the 
it will be observed that those orbits which are nearest to t 
earth will cross one another; and that others still will ross a 
distances varying all the way from one-fourth of the distance 
the moon to many millions of miles, And, since the d 
of tangents or asymptotes diminishes almost exactly as the Pe 
