1863.] 575 



IV. "On the Belts of Jupiter/' in a Note addressed to the 

 Secretary. By JOHN PHILLIPS, M.A., LL.D., Professor 

 of Geology, Oxford. Received May 5, 1863. 



Oxford, 4th May, 1863. 



DEAR SIR, The favourable position of Jupiter for scrutiny of his 

 physical features may perhaps have already brought to the Royal 

 Society some notice of the aspect of his belts. Whether that be so 

 or not, I think you will readily excuse the desire I feel to lay before 

 the Society a sketch from my equatorial, which shows the colours of 

 several celestial objects more distinctly than I am accustomed to 

 hear is the case with some other instruments of the achromatic class. 



The sketch shows the usual equatorial bands*, or rather bands 

 nearly in the usual latitudes north and south of the equator. These, 

 to the eyes of my friends and to mine, appear not dark grey, or 

 greyish brown, or brown, but nearly of the colour of some ochraceous 

 sands, or the yellower parts of what is called " red " deal. Several 

 friends to whom I have shown the planet have immediately exclaimed, 

 "how red the bands are ; " "never saw them so red before." 



The bands far from the equator are not reddened, but of a grey 

 tint a little warmed. The space between the equatorial bands, some- 

 times described as yellow, appears rather bright white and silvery 

 much the brightest part of the surface. The outer borders of the 

 equatorial bands are not parallel, the inner borders much unequal ; 

 in one part the two bands are connected across. 



Not the faintest trace of such a tint as that conspicuous in these 

 bands appears on any part of the moon ; but it is pretty nearly the 

 tint of the supposed " land " of Mars. In fact, it was suggested to 

 my mind that these coloured extra-equatorial belts were land, seen 

 between white clouds, of which the brightest band was on the equator. 



JOHN PHILLIPS, M.A., LL.D., F.R.S., 



Professor of Geology, Oxford. 



* The coloured drawing sent with this letter is preserved at the Royal 

 Society. 



