460 Scientific Proceedings, Royal Dublin Society. 
Professor Bredichin continues his researches on the repulsive 
action of the sun on cometary matter.* 
In a short communication to the British Association Mr. G. J. 
Stoney put forward the hypothesis, that the bright lines in the 
spectra of comets are due to the sun’s light falling upon the com- 
pound of carbon in them, and rendering it visible in the same way 
that light renders other opaque bodies visible, the vapour being 
opaque in reference to the particular rays which appear as bright 
lines in the spectrum. The visibility of comets he attributes to 
phosphorescence, the conditions for the productions of which are 
present in the very attenuated vapour. 
_ Professor H. A. Newton communicated at the same meeting a 
short paper on the direct motion of periodic comets of short 
period. If these comets originally came from interstellar space, 
they must have been turned into the short orbits by coming very 
near to a large planet, the disturbing influence of which dimin- 
ished their velocity. It is now shown in the paper that nearly 
all comets which are thrown into an orbit of short period in this 
way, will have a direct motion in the latter. This is in accord- 
ance with experience, as only Halley’s comet and the Leonid- 
comet (1866 I) have retrograde motions. 
9. Meteors and Meteorites. 
A very complete report on the progress of meteoric astronomy 
during 1878, by A. S. Herschel, formed part of the annual report 
of the Council of the R.A.S.,in February, 1879. As usual the 
same author has prepared a most valuable report to the British 
Association. 
The June number of the American Journal contains a list of 
thirty-two radiant points, by Mr. Sawyer. Particulars as to 
velocity, brightness, and length of path of the meteors of each 
shower are given. The list is founded on records of upwards of 
600 shooting stars. 
Mr. Denning has an article in The Observatory (III., p. 127), on 
“Fireball Epochs,” giving a brief monthly summary of the results 
as to frequency and radiants derived from an examination of 
all published records of aerolites and bolides. The same writer 
* Annales de l’Observatoire de Moscou, Vol. V. & VI., Part I. A.N. 2237, 41, 57, 66. 
