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question the explanation which a writer offers of his own words. But it 
must, we think, he conceded that Professor Stokes and Messrs. Huggins and 
Proctor had some reason for understanding Mr. Stone’s paper as they <rid, 
and that among the many excellent scientific qualities possessed by the 
Astronomer Royal at the Cape, the power of clearly and unmistakably indi- 
cating his meaning must not be included. 
Specular Reflexion from Venus. — Mr. Christie, assistant observer at Green- 
wich, continues to surprise students of science by the support which he gives 
to certain utterly preposterous notions respecting the celestial planets, which 
have been advanced of late by an admirable landscape painter, who seems 
very little acquainted with astronomical and optical laws. He now advocates 
the theory that Venus has a surface not merely possessing the power of 
reflecting light specularly, but also having metallic brightness and hardness. 
Although this theory is one of those which not only cannot be accepted but 
cannot seriously be attacked (standing somewhat on the footing of the older 
absurdity that the moon is made of green cheese, a theory never yet oppugned 
to the best of our belief), yet it seems to us that the observation on which 
the absurdity has been based is worthy of attentive consideration. It is this, 
that the brightest point of the disc of Venus, when the disc of the planet is 
gibbous (and recently the same has been found to be the case when the disc 
is crescent-shaped) lies within the limb, in about the position where an 
image of the sun could be seen if Venus had a metallic (and properly 
polished) surface. These observations have been confirmed (and some of 
them originally made) at Greenwich by Messrs. Christie and Maunder, and 
by Captain Tupman. Thus on January 9 and 10, 1878, “I had,” says Mr. 
Christie, “ an opportunity of examining Venus in the daytime, and I was 
fortunate in securing Captain Tupman’s co-operation on these occasions. As 
seen with an ordinary eyepiece (power 500), Venus appeared 'as a crescent 
having a breadth equal to about two-thirds of the radius, with a bright arc 
near the limb. This arc shaded off perceptibly towards the cusps. On apply- 
ing the solar eyepiece, which reduces the light (by virtue of the three 
reflexions from the glass) to one 3000th part, both Captain Tupman and I 
satisfied ourselves that there was a bright elongated patch distinctly within 
the limb. In the centre of this I caught glimpses of a small point of light, 
the distance of which from the apparent limb I estimated as rather more 
than 0*1 of the radius. The position of the point at which specular reflexion 
would take place I afterwards found by calculation to be 0T8 of the radius 
within the limb.” Captain Noble had in June, 1876, under similar conditions 
of illumination, failed to detect any gradation of light whatever towards the 
limb. He recognized a patch of sensible area “without the slightest sign, 
trace, or indication ” (we are not sure what distinction is intended to be 
drawn here between signs, traces, and indications) “ of one part being in the 
smallest degree brighter than another.” Mr. Christie considers that had 
Captain Noble looked more closely, he would perhaps have detected in the 
middle of the bright patch a small bright point as Mr. Christie did. Be this 
as it may, what Captain Noble saw, while certainly inconsistent with the 
theory that Venus has a simply rough surface or mat surface without any 
specular reflexion whatever, and equally inconsistent with the theory that 
Venus has a purely specularly reflective surface, in which case we should 
