274 REPORT—1874. 
meteor’s visible flight of 15:5 seconds, from these accounts, gives the 
diminished meteor-speed marked (b) in the above Table; no reason for further 
extending the possible time of the meteov’s flight is in any way suggested by 
the scattered examples of less complete observations of its whole course and 
duration that appear among the accounts received by Dr. Galle from many 
other stations. 
Along this long track of nearly 300 miles the meteor increased gradually 
in size as it advanced, soon growing to the dimensions of a fireball of the 
largest class, which it maintained until it disappeared. The nucleus was pear- 
shaped, tapering to a tail of red sparks, several degrees in length, following 
the head. Some described the nucleus as triple, consisting of three fireballs 
travelling together ; others saw jets of flame, accompanied by detached frag- 
ments, projected occasionally, giving the meteor the appearance of haying a 
serpentine or wavy course. The prevailing colour of the meteor’s light was 
white or yellowish; but in front projecting tongues of red flame, and sparks 
like those emitted from burning iron, gave the light in the forward half of 
the nucleus a reddish cast, only the middle of the head or body of the meteor 
being white or yellow. The following part of the head and some parts of 
the tail that shone brightest were distinctly green. The parts into which 
the meteor separated in bursting were numerous according to some of the 
descriptions—* not descending vertically, but as if projected forwards.” ‘Two 
or three of them appear to have been somewhat larger than the rest. A 
writer at Schreiberhau (Silesia ?) states that before reaching the horizon the 
fireball divided itself into three smaller globes equally bright-coloured with 
the first, which together travelled onwards in the same direction and then 
disappeared. The rocket-like tail of red sparks exhibited by the meteor faded 
away quickly, following the head; but in about the last quarter of its visible 
path a bright white very persistent light streak was left by the meteor on its 
track. It was at first straight, brightest, according to some observers, at the 
edges, as if hollow and cylindrical; it speedily, however, became curved and 
zigzag, and separated itself into shining clouds, whose bright white was visible 
in the sky for nearly half an hour. The time of the meteor’s appearance 
being at about a quarter before nine, and the time when the sun set below 
the horizon of the meteor’s point of explosion over Zittau, as found by Dr. 
Galle, having been only at a quarter after nine o’clock, it follows that the 
meteor-streak was exposed throughout the time of its visibility to the direct 
rays of the setting sun, and the brightness of its white light as long as it 
could be traced on the darkening background of the evening sky is thus 
accounted for. All the higher masses of the light streak had at the latter 
time quite dissolved away, and the utmost period of visibility of its knots 
and wisps as a distinguishable vapour does not appear to have exceeded half 
an hour. Dr. Galle calculates that it extended from a height of about 37 
miles at its commencement to a height of about 20 miles, the point of explo- 
sion of the fireball; with a real length, when first deposited, of about 69 
miles, and a real diameter, taking that of the fireball (as seen by observers 
40 or 50 miles from its path, about one third the apparent diameter of the 
moon) as its least width, of not less than 230 yards. Its substance Dr. 
Galle considers to have been either dust or volumes of still more finely 
divided particles of smoke. Another question of great physical interest dis- 
cussed in this paper is that of the time taken by the sounds of the reports to 
reach observers, and the distances to which they were heard round the point 
of explosion of the fireball, From the least of the time-intervals (about 
1™ 39° at Grossschénau) to the greatest calculated (at Neukirch, 4" 35%) 
