THE AUGUST METEORS. 
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elevation of the radiant, a corresponding increase in the hourly 
number of meteors. In 1877, at Bristol, the eastern sky was 
persistently watched between 9 h 30 m and 14 h 30 m , when 354 
meteors were seen ; and though the horary rate before ll h was 
only 47, it rose to about 80 during the last half of the watch. 
Indeed the number of meteors observed at the end of the 
watch was more than double the number recorded at the 
beginning of it. Thus it is apparent that the most favourable 
time for such observations is in the morning hours, and 
though it is generally inconvenient for amateurs to extend 
their vigils thus far, the importance of doing so cannot he too 
strongly insisted on. 
A typical feature of the Perseids is to be found in the streaks 
which frequently mark their course (fig. 1), and serve an ex- 
tremely useful purpose in enabling the directions to be registered 
with great accuracy. The theoretical velocity of these meteors 
is thirty-eight miles per second, so that they belong to the swift- 
est class of such bodies, and, as such, would be individually re- 
Fig. 1. — Broken Streak of a Perseid in Pegasus, Aug. 11, ll 11 10 m . 
corded with much difficulty, were it not for the special 
feature referred to. Their very rapid transient flights would 
baffle the observer as he stood endeavouring to retain the exact 
points of beginning and ending ; and in the majority of 
instances he must absolutely fail to get nearer than a mere ap- 
proximation. Only in cases where the meteors sped from one 
star to another, or in courses parallel to closely adjoining stars, 
could the paths be truthfully reproduced on his map. But 
fortunately for such investigations, we have no such difficulties 
to encounter. The phosphorescent line almost invariably 
projected on the sky by the nucleus as it rushes along, 
remains to guide the eye in fixing its position. It is the 
authentic signature of the meteor gone before, and during the 
brief span of its endurance the observer knows how to utilize 
it. It is seldom these streaks last longer than three or four 
seconds, though in exceptional cases of Perseid fireballs they 
have lingered several minutes; The writer found the average 
