THE PLANET JUPITER IN 1869-70. 
137 
readily followed quite to the limb, as in De la Rue’s magnifi- 
cent engraving. Nothing was ever witnessed at all approach- 
ing to the obliteration figured in Beer and Madler’s “Bei- 
trage ; ” nor did the spots disappear, as those authorities found, 
at distances of 52° and 54° from the central meridian, though 
they were much more difficult objects towards the limb. It is 
very conceivable that the planet’s atmosphere may vary greatly 
in different seasons, and much must be allowed for the superior 
power of my instrument. The effect of perspective has, how- 
ever, perhaps not been always borne sufficiently in mind. A 
marking whose visibility depends upon its breadth will dis- 
appear from simple foreshortening in the neighbourhood of the 
limb, while a belt extended in the opposite direction will ex- 
perience no obliteration from that cause. 
The peculiar uniformity of aspect in the central region would 
probably be much broken up, as we know to be the case upon 
the Moon, by the application of greater optical power ; never- 
theless, enough of regularity must remain to indicate the action 
of some widely extended but unknown law. The very limited 
access which I at present possess to the necessary materials for 
comparison induces me to postpone an enquiry into the occa- 
sional, if not frequent, recurrence of this remarkable pheno- 
menon; and it may well be taken up by more competent 
hands. Such recurrence of configuration, however, and that 
not confined solely to the region of the equator, may be at once 
indicated as matter of the highest probability. Very marvellous 
arrangements evidently exist upon that planet, and forces are 
in operation, of the nature of which we can at present form 
little other idea, excepting that they must declare the power of 
the Great Creator upon a scale of surpassing magnitude. 
