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ASTRONOMY: C. P. OLIVIER 
126 PARABOLIC ORBITS OF METEOR STREAMS 
By Charles P. Olivier 
LEANDER McCORMICK OBSERVATORY. UNIVERSITY OF VIRGINIA 
Presented to the Academy, May 10, 1915 
The study of meteors as astronomical bodies began in the early part 
of the last century. The occurrence of the great showers of 1833 and 
1866 showed the importance of the meteoric astronomy. When it was 
proved, soon after the latter appearance, that this meteor stream and 
Tempel's Comet of 1866 had the same orbit about the sun, the interest 
in meteors increased enormously. Though millions of meteors are 
swept up by the earth every twenty-four hours, still these Httle bodies 
also obey the law of gravitation, and, in obedience to this law, meteors 
pursue their orbits about the sun. 
Astronomy is interested in proving the connection between comets 
and meteors, in investigating the distribution of meteoric matter in 
space with special regard to that near the earth's orbit, in finding the 
cause of the zodiacal light, and the action of meteoric matter as a re- 
sisting medium and as an absorber of Hght in space. Meteorology is 
interested in the study of meteor trains and meteor heights, because 
the former give us our only information about the velocity and directions 
of wind currents in the upper strata of our atmosphere, the latter cer- 
tain information as to how high this atmosphere must extend. 
To arouse interest in this subject the American Meteor Society was 
organized in 1911, and the results mentioned in this paper were worked 
out from the 2800 observations contributed by its members. These 
results appear in full in Volume 2, Part 4, of the Publications of the 
Leander McCormick Observatory of the University of Virginia. While 
the most important contribution to science was the 126 parabolic orbits 
of meteor streams, the most interesting result, undoubtedly, was the 
final proof of the connection of Halley 's Comet and the i) Aquarid meteors. 
These bodies were shown to follow orbits similar to Halley's Comet 
and present one of the best instances of the slow disintegration of such 
a body. The question whether radiants are stationary was studied in 
considerable detail, and a negative conclusion was reached, principally 
because motion was detected in the radiant point of the Orionid meteors, 
which are held to be the typical case by certain authorities. The 
tabular results of the paper are of interest to anyone who has even 
touched on the subject, showing as they do at a glance just what one can 
expect from a few hours' observation at favorable times of the year. 
The National Academy of Sciences at its annual meeting has granted 
