METEORS AND METEOR SYSTEMS. 
19 
The shower, No. III., near ft Trianguli , is lj° N. of that 
star, and nearly all the meteors diverging from it have been 
short, appearing amongst the well-known stars of Perseus , 
Auriga, and Andromeda. At first they are very swift, streak- 
leaving meteors, but at each later manifestation the velocity 
decreases, and they are rarely accompanied by streaks. It is 
a remarkable fact, that though I have seen 4400 meteors 
(exclusive of the August Perseids) during the last six months 
of the years 1876-79, nearly all of them amongst the con- 
stellations included in the zone from Pegasus — Lacerta to Leo — 
Ursa, yet I have never found a meteor- shower precisely at 
ft Trianguli, or slightly below that star, or to the east or west 
of it. Over and over again the radiant point reappears at the 
same place, so far as the necessarily approximate nature of the 
observations will allow one to determine. From Auriga, too, the 
meteors constantly fall from a centre about 2° E of aline joining 
ft Tauri and i Aurigce* and below an elongated group of small 
small stars there. (See No. IX.) In Perseus there are also 
several well- determined points of departure extending over a 
few months ; and it now remains for observers to further inves- 
tigate the alleged peculiarities. The importance of the subject 
cannot be over-estimated. It is impossible that meteor- showers 
can last longer than a few nights (except under special con- 
ditions), on the assumption that they form parabolic orbits, 
and that the true cometary- meteor- showers of August 10, 
November 13 and 27, &c., are to be accepted as typical streams 
belonging to the solar system. Unless the meteor-rings are 
of great width, or unless their orbital directions are nearly 
parallel with the Earth’s motion, it is certain that the showers 
must be very short-lived, because the Earth’s orbital velocity of 
about 18 J miles per second carries her on about 1J million 
of miles in a day, and she must quickly traverse the stream in- 
tercepting her path, unless, indeed, it is diffused over a vast area 
of space, in which case the showers might possibly be sustained 
several months, but not without a change in the position of the 
radiant point. Evidently the identity of a comet with a star- 
shower is only safely to be inferred when the position and 
epochs of the two radiants are in exact conformity. Amongst 
the very large number of such systems existing in space, there 
must be many varieties of orbit and origin, and the complicated 
effect of planetary perturbations upon such slender streams is 
perhaps not yet sufficiently known or appreciated in its full 
significance. Towards the ultimate explanation of such ano- 
malies as observations have induced, we require much further 
assiduous labour in the same field. 
Those who have worked in this department of astronomy will 
* There is an equally persistent centre 25° N. of this at 77° + 57°. 
