1872.] Meteoric Astronomy. 147 
longitude of node and of perihelion, and so on, afforded 
so many additional evidences of coincidence. The fact 
is, that setting aside Schiaparelli’s assumption as to the 
meteoric velocities, there is no agreement as respects any 
of these elements except the longitude of the node. There 
is a further coincidence not directly expressible in the 
ordinary orbit elements, and this coincidence, as indicated 
above, is sufficiently striking. It justifies, in fact, the 
assumption of equal velocities. Then this assumption 
being made, and leading to the coincidence of the actual 
direction of the two orbits where they cross the earth’s, 
the exact coincidence of the two orbits, in all respects, 
follows inevitably,—since two bodies moving with equal 
velocities and in the same direction as they cross one and 
the same point in interplanetary space, must, by the law of 
gravity, follow identical orbits. 
Or the matter may be otherwise expressed thus:—It 
follows from a discussion of the motions of the comet of 
1862, that if the earth had been close by the place where 
her orbit is crossed by the comet when the comet actually 
traversed that place the comet’s course would have seemed 
to be directed from the radiant of the August meteors. So 
much 1s certain. Schiaparelli inferred that the actual course 
of the comet as respects velocity and direction was identical 
with the course of the August meteors as they traverse the 
earth’s orbit. We have already had occasion to consider 
the probability of such an inference, in speaking of the 
probable association between all the meteors which on any 
night appear to have the same radiant. The chances are 
great against the coincidence being accidental. 
If I were here dealing with the history of meteoric 
astronomy, I should have to give a full account of the 
recognition of a corresponding resemblance between the 
motions of the November meteors and those of Tempel’s 
comet (No. I., 1866). In particular, it would be desirable 
to discuss the share which Professor Adams took in the 
work. I notice with regret, by the way, that in Dr. Schel- 
len’s useful work on ‘Spectrum Analysis,” the labours of 
Adams are left wholly unrecognised, while the compara- 
tively less important researches of Schiaparelli, Oppolzer, 
Peters, and Leverrier, are pointedly referred to. This is not 
the place to supply the omission ; but I may remark that if 
we set aside the labours of Adams, the only circumstance in 
which the discussion of the November meteors differed from 
that of the August meteors were these: there was, first, a 
reason for assigning a particular period to the November 
