SCIENTIFIC SUMAEY. 
81 
Stokes regarded the polariscopic observations of the corona as seemingly- 
implying the existence of minute metallic crystals, situated and moving 
much as the theory advocated by Mr, Proctor appeared to require. It 
should be added that Mr. Ranyard had himself inferred, from polariscopic 
observations of the zodiacal light by Mr. Burton, that either u it consists of 
matter in particles so small that their diameters are comparable with the 
wave-lengths of light, or it consists of matter capable of giving specular 
reflexion.” Either view (or the two views accepted together) would singu- 
larly confirm the expulsion theory. 
The imagined Change in the Nebula surrounding Eta Argus. — Mr. Lassell, 
President of the Astronomical Society, has expressed the opinion that Mr. 
Abbott’s evidence is altogether insufficient to establish the imagined changes 
of this wonderful nebula. Mr. Proctor, who had been (as was the Astro- 
nomer Royal) one of the believers in a change, has expressed his full agree- 
ment with Capt. Herschel’s explanation that Mr. Abbott had completely 
misunderstood what he was looking at. The lemniscate is, in fact, far too 
minute a feature for the aperture and low powers employed by Mr. Abbott. 
It is a most unfortunate thing that the time of Sir J. Herschel, Airy, Lassell, 
and many others should have been wasted through Mr. Abbott’s carelessness 
and over-confident assertions. 
Encke’s Comet. — Mr. Carpenter, of the Greenwich Observatory, remarks 
respecting this object, as seen with the transit circle and the great equatorial, 
“I was able to make out a considerable extension of the illumination 
beyond the bright fan-shaped condensation, but on one side (the spreading 
side) only. On the opposite side this diffused illumination appeared to be 
cut off nearly in a straight line immediately behind the apex of the fan.” 
He adds that “ the comet was easily seen in the finder of the great equa- 
torial.” 
Inferior Conjunction of Venus . — On September 26 Captain Noble observed 
Venus 1 h. 37 m. after she had passed her inferior conjunction. The state of 
the atmosphere was too bad to admit of any attempt at micrometrical 
measurements, but he estimated that her illuminated crescent occupied a 
little more than a third of her circumference. He remarks, “My chief 
reason, however, for putting this observation on record is that I quite failed 
to see the dark body of the planet, which, under analogous conditions, has 
always been visible enough before in a constricted field. Doubtless the 
wretched state of the air may have had something to do with it j but is it 
possible that the bright background (whatever it may be) on which Venus 
may be projected, varies in lustre ? ” We should say it is not merely pro- 
bable, but certain, that the lustre of the corona is variable. 
The Construction of the Heavens. — Mr. Proctor, speaking of the evidence 
respecting the construction of the heavens derived from his chart of 324,198 
stars, remarks (“ Monthly Notices ” for November), “ Struve’s general con- 
clusion that the stars of the first nine or ten orders of magnitude are more 
densely aggregated along the galactic zone is abundantly justified. But 
instead of a gradual increase of density such as his statistics suggested, we 
recognise in the chart a distinctly marked aggregation within those very 
regions of the heavens where the Milky Way is brightest to the eye. In 
other words, we have clear evidence that it is not towards a certain zone 
YOL. XI. — NO. XLII. G 
