644 Fireball Radiant in Sextans. November, 
magnitude. The former difference is tiie natural outcome 
of the change in the astronomical conditions affecting the 
apparent motions of the meteor particles relatively to that 
of the earth at the two epochs. Thus in November, when 
the radiant is near the earth’s apex, the velocity of the par- 
ticles at impact is near the maximum (about 44 miles per 
second), inasmuch as they fully confront the earth, and there 
is a direct rencontre at that time. The orbital motions of 
the earth (i8‘5 miles per second) and meteors (26 miles per 
second) are therefore combined in the observed effects. But 
early in February the circumstances are very different, the 
relative diredtions being nearly at right angles ; hence the 
apparent velocity of the meteors accords with their real or 
native velocity. Later on this becomes further reduced, 
until the radiant point being near the earth’s anti-apex, and 
the paths of the meteors and the earth being parallel in the 
same diredtion, the apparent meteor speed reaches a mini- 
mum of some 11 miles a second. Even during short periods 
great changes are effected in the conditions under which 
meteor showers are presented to our observation, and they 
are of such character as to suggest the utter inconsistency 
of individual streams having very long durations and fixed 
radiant points. But the fact of these consecutive showers 
from the same derivative point in Sextans is so well attested, 
and the same peculiarity so clearly demonstrated in regard 
to many other systems, that (though we may admit the 
difficulties attending its explanation) the subject should not 
be lost sight of by those who would form a right conception 
as to the phenomena of meteors. Anomalies of the cha- 
radter referred to may tend to induce further investigation, 
and lead us to modify our views as to the visible behaviour 
of certain streams which may show a width and construction 
of orbit entirely opposed to such well-defined though fugitive 
displays as the Quadrantids, Lyrids, Andromedes, and 
Leonids, which constitute groups of very special character, 
and cannot be regarded as typical of the multitude of more 
attenuated and apparently long-enduring showers with which 
the heavens so numerously abound. 
It is worthy of note that this well-defined radiant point 
in Sextans does not appear in the catalogue of Sig. Schia- 
parelli’s reductions of Zezioli’s meteors of 1867-70, which 
contains a very large number of observations for the earlier 
months of the year. The shower was not quiescent at that 
time, as we know from Col. Tupman’s records, which were 
of contemporary date. There is also no mention of this 
position in either of the extensive catalogues of Heis and 
