70 THE BORDERLAND OF SCIENCE. 



moment growing more marked in character. I do not 

 know how I can better illustrate the nature of the 

 changes taking place in the great equatorial belt, than 

 by comparing its appearance to that of shifting clouds 

 of steam strongly illuminated by concealed fires. The 

 neighbouring belts were equally changeful in aspect ; 

 but they presented at all times a much greater depth 

 and variety of, colour. It was as though not white 

 steam-clouds, but masses of coloured gas were illumi- 

 nated by a continually changing glow. The colours 

 were even more variegated near the planet's poles ; 

 though here the changes were less rapid and remarkable. 

 The general blue colour of these regions seemed to be 

 due to the presence of an overhanging pall of blue 

 vapour, through which from time to time a purplish 

 glow could be recognised in certain spots. 



These appearances were so remarkable, and seemed 

 so obviously to belong to the planet itself, and not to 

 be caused by the varying effects of the sun's light, that 

 we determined as we drew near the planet (and when 

 we were already past the inner edge of the dark ring) 

 to circle round Saturn's globe so as to reach its un- 

 illumined side, before passing beneath the planet's 

 atmosphere. 



We did so, penetrating into the vast shadow pro- 

 jected by the planet into space. Instead, however, of 

 the black darkness which might have been expected, 

 we found that all the part of the planet which at the 

 moment was turned from the sun, was aglow with a some- 

 what dull luminosity, like that of fire shining through 



