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POPULAR SCIENCE REVIEW. 
1 ‘8 seconds from many observations in August 1880 ; and 
the most frequent duration is about two seconds. All the 
brighter meteors of the sho'wer display them. Mr. Henry 
Corder, of Writtle, has observed these Perseids with great 
diligence in recent years, and retained many interesting notes 
of their peculiarities. Of 910 meteors belonging to this system, 
which he saw in the years 1871-79, 526 were accompanied 
by streaks. These included 158 of the first magnitude, only 
15 of which were devoid of streaks ; and 243 of the second 
magnitude, of which 72 were streakless. Amongst the 
smaller members the proportion was larger. He found the 
brightest meteors were generally pale-green, others orange, &c. 
The luminous streaks, which are known to be the ordinary 
characteristic of these shooting stars, have acquired a special 
significance from the fact that by their means the radiant 
point of the shower is capable of being ascertained with 
remarkable precision. This important element, to be reliably 
determined, must rest upon a large number of accurately 
recorded tracks, which intersect (on being prolonged back- 
wards) at a well-defined position. Many observers have suc- 
ceeded in finding this from results of more or less value. 
Mr. P. P. Greg analysed all the positions estimated prior to 
1876, and gave the average at P.A. 44°, Dec. 56° H. ; and 
Major Tupman, from a discussion of his own elaborate obser- 
vations in the Mediterranean during the years 1869-71, 
derived the point 45 + 56°, as the centre of 28 sub-radiants. 
Evidently the two results, being founded on a large number of 
trustworthy records, and agreeing so closely as they did, 
showed the true radiant to be situated on the northern limit 
of Perseus , close to the star Eta of that constellation ; and 
more recent determinations of a similar nature have fully 
corroborated that as the chief diverging centre of the August 
meteors. Many other contemporary showers have been de- 
tected in the same region of the heavens, but the shower of 
Perseids recurs year after year from its accustomed point. 
During the last eleven years the writer at Bristol has 
awaited the annual returns of this shower, and the aggregate 
results of observations during the interval between the 6th 
and 12th August, show that 2345 meteors have been re- 
corded, of which 1428 belonged to the display of Perseids, and 
917 to other minor streams of the same epoch. In 1869 the 
radiant was judged to be at rj Persei ; in 1871 at B. Camelo- 
pardi ; and in 1874 at 44° -f- 58J°. The average position found 
during the last five years has been at 44° + 57° ; and in the 
diagram (fig. 2) a number of paths near this radiant are shown. 
Some of the meteors appear to be slightly erratic in their 
directions; but this may be explained either by errors of 
