METEORS AND METEOR SYSTEMS. 
21 
coincides with the line of sight) are also of great utility, as they 
obviously appear in the immediate region of the radiant point. 
Large meteors, such as bolides and fireballs, when observed at 
several different stations, offer another means of deriving true 
radiant points, though it is not often that the descriptions of 
those who witness such brilliant objects are found to agree 
and to admit of satisfactory comparison. But when, as occa- 
sionally happens, the phenomenon is independently recorded by 
several practised observers, the orbital elements may sometimes 
be derived with similar accuracy to those of a well-observed 
comet. The radiant points of large meteors thus derived are 
strictly comparable with the ordinary feeble showers of small 
shooting-stars, because there is no doubt they proceed from 
identical systems. The Perseids of August, and the Leonids 
of November, supply meteors of all magnitudes, from the 
faintest class just within the limits of vision up to the largest 
type of fireballs. Numerous other systems, amongst which 
may be mentioned the November Taurids, also display the 
same variety in the brilliancy of their members. The great 
detonating fireball of November 23, 1877, whose radiant point 
was very exactly defined (by five good descriptions of the line 
of flight) in Taurus at 62° + 21° belonged to the system of 
Taurids noted by Mr. Greg as a conspicuous shower in November, 
and well seen by the writer on November 20, 1876, at the 
point 62° + 22 |°. The large detonating meteor seen in the 
early evening of November 21, 1865, with a radiant point 
at 56° + 13° appears also to have belonged to the same stream. 
The great fireball of May 12, 1878, nearly coincided in its 
radiant point (214° — 7°) with a well- determined radiant at 
207° —8° in April — May; and on August 11, 1876, a large 
meteor was seen at many places, the recorded paths indi- 
cating a good radiant point at 60° + 51°, corresponding with a 
shower traced by the writer at 60° + 50° on August 12, 1877. 
Many other corroborative radiants of large fireballs, with 
ordinary star- showers, might be adduced to confirm the idea 
that they belong to the same individual systems, though in 
some cases, it must be admitted, the agreements may be 
accidental. Prof, von Niessl regards detonating and aerolitic 
meteors as a distinct class of cosmical bodies, which differ from 
comets and periodical meteor- showers in the original velocities 
with which they enter the sphere^of the Sun’s attraction. He 
has assigned hyperbolic elements to the orbits of several fire- 
balls, and expresses his conviction that they have native 
velocities in space bringing them from remote star-spheres into 
the neighbourhood of the solar system.* 
It is fair to conjecture that, amongst the vast assemblage of 
* B. A. Report, 1877, p. 146. 
