May 7, 1885] 
represented by symbols that obey the laws that Maxwell has 
shown should be the laws of symbols representing the condition 
of a medium that would explain electric and magnetic pheno- 
mena. It seems very unlikely that any jelly is at all /ée the 
ether that Maxwell supposes. It seems much more likely that 
what he called ‘‘ electric displacements ” are changes in structure 
of the elements of the ether, and not actual displacements of the 
elements. He guards against this being supposed a necessary 
part of his theory when he defines polarisation in terms that 
certainly require a change of structure rather than a change of 
position, so that I think the word ‘‘ displacement” was un- 
fortunately chosen. I also think that Sir Wm. Thomson, not- 
withstanding his guarded statements on the subject, is lending 
his overwhelming authority to a view of the ether which is not 
justified by our present knowledge and which may lead to the 
same unfortunate results in delaying the progress of science as 
arose from Sir Isaac Newton’s equally guarded advocacy of the 
corpuscular theory of optics. Gro, FRAS. FITZGERALD 
40, Trinity College, April 25 
The April Meteors 
In 1882 the Lyrid meteor shower (epoch, April 19-20) was 
noticed to be far more conspicuous than usual. The display had 
been quiescent for some years ; it appeared to have degenerated 
into a third rate shower, scarcely deserving the trouble of ob- 
servation. But in the year mentioned the stream gave distinct 
intimation of greater intensity, and showed the necessity of 
continuing annual observations of periodical showers such as 
this, even though they may exhibit, during a comparatively long 
interval, but a very feeble sustenance of the richness recorded in 
former times. 
On April 20, 1882, Mr. Corder, at Chelmsford, watching for 
three hours between dusk and 12h. 30m., counted 26 Lyrids 
and 8 meteors belonging to other contemporary radiants of minor 
character. He regarded the horary rate of apparition on that 
occasion as about two or three times as high as on any other 
occasion since 1877, when he had been able to watch for the 
display. He found the radiant at 268°+ 37°, and remarked that 
four of the meteors seen were as brilliant as first-magnitude 
stars, but he had never found them a very interesting species in 
respect to their visible appearances. 
No observations of the shower were obtained in 1883, the 
moon being near the full at the time of its occurrence ; but in 
1884 the conditions were more favourable. On the night of 
April 19, in the hour preceding midnight, 17 Lyrids were ob- 
served by the writer at Bristol. During the last quarter of an 
hour of the watch the sky was much clouded, and only one 
Lyrid seen. The horary number was computed as 22 for one 
observer—evidently, therefore, the display of 1884 was a notable 
one, and it was very unfortunate that a clouded sky prevented 
the development of the shower being watched through the morn- 
ing hours of April 20, when possibly it may have attained a 
richness without parallel in late years. On the evening of 
April 20 it had evidently become exhausted, for in a watch of 
twenty minutes not a single shooting-star appeared, though the 
sky was very clear. 
The present return of the Lyrids occurred under very auspicious 
circumstances. | The moon offered no impediment to morning 
observations, which is far the best time to watch for these 
meteors, as the radiant, west of a Lyrz, is very low in the 
evening hours. The nights of April 17, 18, 19, and 20 were 
cloudless throughout, and on the three latter dates observations 
were made here with the following results :— 
Duration 
Period of Meteors Lyrids Radiant 
Date hm. h. m. Watch seen seen Ieee 
o o 
April18 ... 12 oto 1430 Olen eee 6 260 + 334 | 
SeLON--ei ZOFS0i(b! x4) (0 3 26 10 2673 + 33.7 
Sy zal Pres OtO EE SIO) secu 4a ene SQ 14 274 +3343 
Ap. 18-20 «. 10 30101530 «. ob .. 84 ey od 267°2+33°3 
After April 20 moonlight and cloudy weather effectually pre- 
vented further work. 
The table furnishes us with some interesting facts. It shows 
that during the three nights the proportion of Lyrids to uncon- 
formable meteors was very nearly the same, namely, as 3 to 5, 
and that the horary rate of their apparition was little more than 
3. It also shows a very marked displacement of the radiant (in 
t Sky clear; slight haze. 2718: 3 Sky very clear. 
NATORE 
5 
the direction of east longitude) from night to night. I regard 
this as the most interesting and certain feature observed. The 
three centres resulting from the paths of short meteors, observed 
with the utmost care, may each be relied on as very accurate. It 
therefore appears most conclusive that the radiant point of the 
Lyrids, similar to that of the August Perseids, increases in right 
ascension from night to night, and the extent of this displace- 
ment is even greater for the Lyrids than for the Perseids. 
On April 19, 1884, 114h., I found the radiant at 269° + 33°, 
and on April 19, 1885, 12th. (the middle time of the observa- 
tion), at 2674° + 33°. Allowing for the difference (about 12’) in 
the sun’s longitude at the two epochs in applying the correction 
for the displacement of the radiant (7° of R.A. daily) observed 
this year, we shall find that the two positions are in exact 
agreement. 
The recent display has been decidedly meagre in point of 
numbers. There is a great falling off since last year, when the 
horary rate was nearly eight times as great. But some of the 
meteors observed this year were very bright and in a great measure 
compensated for their scanty apparitions. It is curiousthat three of 
the most brilliant Lyrids, equal to or exceeding Jupiter, appeared in 
nearly the same region of the western boundaries of Virgo. On 
April 18, at 12h. 57m., one of these fell, with a bright flash and 
streak, 10° east of Spica Virginis. Another on April 20, at 
13h. 14m., came out very suddenly 7° above that star; and a 
third, at 14h. 1m., descended, with a swift, diving motion, about 
13° east of the star, so that the path was nearly similar to that 
of the first of the three. These five meteors gave transient 
Ly 
#49 
26th. 
Ss 
Diagram exhibiting the displacement in the radiant point amongst the stars 
of Hercules and Lyra on the nights of April 18, 19, and 20, 1885. 
flashes of yellowish-white light, which brightly illumined the 
mist lying along the horizon, and left short streaks of very brief 
duration. I saw four other Lyrids, quite equal to first-magnitude 
stars, and these, together with the fainter members of the same 
shower, were nearly all registered amongst the stars surrounding 
Lyra, especially those of Hercules, Draco, and Aquila. Alto- 
gether I regard the April display of this year as one of con- 
siderable importance, for though much less rich than in 1884, it 
furnished meteors of greater interest and brilliancy. The low 
position of the radiant during observations last year may have 
influenced the visible aspect of the meteors from Lyra, especially 
as regards the swift, flashing characteristic so invariably noticed 
this year in the brighter members, or, possibly, the explanation 
may be that near the richer portion of the stream the corpuscles 
are smaller in almost the same ratio as the increased condensa- 
tion, It will be advisable to regard this question during future 
observations of this shower, and especially the new feature 
detected this year as to the evident shifting of the radiant point 
from night to night. I believe the maximum of the shower is 
usually attained with the radiant at 2695° + 33° (the radiant 
point of its allied Comet I. r861 is 270}° + 32°). If the display 
extends over as long as seven days, and the radiant shifts 7° in 
R.A. every day, it is curious that the meteors will be /7ercaulids 
on April 17, 18, and 19, Zyréds on April 20, 21, 22, and 23, and 
then Cygv7ds on April 24. 
Contemporary with the special periodical display of this epoch 
there are vast numbers of feeble systems which annually give 
