August 19, 1886] 
Watching the eastern sky between roh. and r4$h., I counted 
50 meteors, and of these 12 were Perseids displaying the normal 
features. The radiant-point was, at 33° + 55°, not very sharply 
defined. Some of the best observed paths were slightly dis- 
cordant, and gave the impression that the focus of divergence 
was diffused over an area of 3° or 4° diameter. 
The following night was cloudy, but August 4 came in very 
clear, and 58 meteors were seen between toh. and 14$h. 
Amongst these were 12 Perseids, and the radiant-point, more 
contracted and definite than on the 2nd, was now at 37° + 57°, 
having increased 4° in R.A. in the interim of 48 hours. The 
shower exhibited no increase in numbers between the 2nd and 
4th ; indeed, there appeared to have occurred a slight falling 
off on the latter date. But on the 4th I saw a duplicate shower 
of Perseids, the companion radiant being at 48° + 43°, between 
a and B Persei, and this position was accurately indicated from 
seven paths. 
A cloudy period supervened between the 4th and roth, but on 
the latter night the sky was very clear throughout, though the 
moon was up until 13h. 30m. etween toh. and r14$h. I ob- 
served 152 meteors, though the watch was not persistent during 
that interval. The number seen included 122 Perseids with a 
radiant at 44° + 573. At 13h. 6 meteors were noted within 
20 seconds, and after the moon had fallen below the horizon the 
shower developed into one of considerable activity. Between 
14h. and 14h, 15m. I counted 22 meteors, so that they were 
coming at the rate of about 90 per hour for one observer. Some 
of them were unusually bright. At 13h. 34m. a splendid 
Perseid appeared in the northern sky, pursuing a path of 13° 
from 77° + 67° to 111° + 67°. It lit up the whole heavens 
with a momentary flash, and left a luminous streak, near the | 
end of its path, that remained visible to the eye for nearly 
4 minutes. This was by far the most conspicuous meteor seen 
during the night, and it will probably have been recorded at 
many other places. 
On August 11 the sky was partly clear between ro$h. and 
11jh., and 22 meteors were noted, including 15 Perseids from 
47 + 57%. Thus the position of the radiant showed a still 
further displacement towards the east. The shower had de- 
clined greatly since the preceding night, and offered little 
attraction in the presence of the bright moonlight. 
The shifting radiant of the Perseids forms one of the most 
curious and important details of its display. I first mentioned 
this feature in NATURE, vol. xvi. p. 362, and have been much 
interested in reobserving it on many subsequent occasions. 
Comparing the four positions determined this year, and one 
obtained on August 13, 1885 (NATURE, vol. xxxii. p. 415), the 
character of the displacement is well shown, and corroborates 
the figures given in the JMJonthly Notices, December 1884, 
pp- 97-8: 
° ° 
MOSOPAUAUSE 2 2.2 ..., 33 4+ 55 12 meteors 
Agha Seb 12), 155 
WO ore os EE Sis oon ong IP 
OTe wcicow ety tegen hte ere a OLS 50 
Tig} Neco eron | GLI sts) © oem ines OO 55 
On the whole the recent shower may be justly regarded as 
one fully answering to expectation. It has been quite equal, if 
indeed it has not surpassed, the Perseid displays as I observed 
them in 1869, 1871, 1874, 1876, 1877, 1878, and 1880. It is, 
however, somewhat difficult to institute perfectly fair compari- 
sons. The circumstances affecting two displays are rarelysif ever 
identical. In some years the shower escapes suitable observa- 
tion owing to cloudy weather just at the important time. In 
others moonlight nearly obliterates it. We must also consider 
that, as the main richness of the stream is limited to a short 
interval, it will occasionally elude us by occurring in daylight. 
These varying conditions and hindrances render it unsafe to draw 
conclusions as to the relative aspect of the annual displays unless 
the evidence is very complete and satisfactory. 
It is well known that an unusually large number of minor 
systems occur simultaneously with the August Perseids. The 
positions of many of these are now ascertained with considerable 
precision, The labours of Heis and Schmidt, ably supple- 
mented by Greg, Alex. Herschel, Zezioli, and others, have fur- 
nished a multitude of observations which are satisfactorily 
accordant as to many of the secondary showers of the epoch. 
The results obtained in the present year have been extremely pro-- 
ductive of tenuous radiants. I select five of these as affording 
instances of very definite showers :— - 
NATURE 
378 
Radiant No. of 
No. 1826 Pea Ss Features 
I... July 27-Aug. rr... 291+51 ... 14 ... Rather slow. 
z... July 31-Aug. 11 ... 350+51 ... If ... Rather swift. 
3... August 2-11... 48+43 ... 10 ... Swift, streaks. 
4 .,. August 2-4 ... 26+42 ... 6... Swift, streaks. 
5 -.. July 31-Aug. 2 20+58 ... 7 ... Swift, streaks. 
Nos. 1 and 2 I observed also in August 1885 (see NATURE, vol. 
xxxli. p. 415), when I derived their radiants at 292° + 52° and 
345 + 53° respectively. No. 3, between a and B Persei, I 
observed in July and August 1877, and again on July 23-25, 
1884 (Monthly Notices, December 1884, p. 107). No. 4, near 
y Andromede, has also been pre-observed here in August 1877 
and 1879; and No. 5 represents the Cassiopeiads, which have 
long been known as a pronounced companion shower to the 
Perseids. 
The position No. 2 at 350° + 51° lies between Cassiopeia and 
Lacerta. It was the most prominent of all the minor streams of 
the August epoch in 1885, and in 1877 I had observed it well 
loth in July and August. It has also been noticed by many 
others in recent years. Taking an average of fifteen different 
observations the radiant comes out at 350°°2 + 52°"1. This par- 
ticular shower, by its increasing activity:during the past few years, 
appears to have supplanted Mr. Greg’s Lacertids at 335° + 52, 
which have evidently not maintained their former strength. It 
is probable also that during the period of Mr. Greg’s researches 
this August shower at about 350 + 52° was comparatively 
quiescent, for there is no reference to it in his catalogue of 1876. 
The same may also be said of the system of Cygnids at about 
29° + 51° (near @ Cygni). Possibly, however, the latter may 
have been formerly confused with the Draconids (= Greg, No. 
78). Inthe ‘‘ Annuaire pour l’an 1885, publié par le Bureau 
des Longitudes” I find that two of the chief showers accom- 
panying the Perseids on August 9-14 are stated as at 345° + 50° 
and 294° + 52°. My recent observations just described confirm 
this pair of showers in the most definite manner, and they will 
doubtless be similarly corroborated wherever systematic obser- 
vations of the Perseids are conducted. 
W. F. DENNING 
THE SWISS SOCIETY OF NATURAL’ 
SCLENGES 
HE annual meeting for this year of the Swiss Society of 
Natural Sciences opened at Geneva on the roth instant under 
the presidentship of Prof. Louis Soret. This precursor of all 
itinerant scientific societies was founded in 1815 in Geneva, and 
the present is its seventh meeting in the city of its birth. The 
members and visitors were received on the evening of the 9th 
in the sa/ovs of the celebrated Palais Eynard, which, after being 
long closed, were opened specially for the occasion. After the 
presidential address on the roth, a new committee for the forth- 
coming period of six years was appointed, with its seat at Berne, 
the next meeting was fixed to take place at Frauenfeld, in 
Thurgau, and Prof. Grubenmann was elected president. 
Prof. Soret in his address first referred to the advantages offered 
by Geneva to men who have taken science for their vocation, and 
then, under the title of ‘‘ Des impressions réitérées,” developed a 
series of new and original ideas on zestheticism analysed by the 
man of science. The repetition, he said, of the same design, 
whether in a symmetrical form, or in lined designs, such as we 
see in tapestry, furniture, or buildings, whether of the same 
dimensions, or of dimensions regularly decreasing, gives an 
agreeable impression. It is the same with regular curves, but 
the zesthetic sensation dwells less in the sensation itself than in 
the intuition which it gives us of alaw. This applies not only 
to form, but also to sound and to colours. Developing these ideas, 
M. Soret insisted on the part played constantly by repetitions and 
similitudes because they evoke by intuition the idea of a law. 
M. Marcel Deprez then read a paper on the transmission of 
force by means of electricity, in which he described his recent 
experiments between Creil and Paris and the results. M. 
Rilliet, of Geneva, read the report of a commission ap- 
pointed to investigate the depth to which light penetrates water. 
Dr. Heim, of Zurich, read a paper on the deformation of fossils 
in mountains. He described the modifications which rocks 
undergo in form eyen after induration. Under the enormous 
pressure of the rocks above they may become laminated without 
any visible solution of continuity in the mass, or any rupture. 
