MR. J. NASMYTH ON THE PLANET xMARS. 303, 



XXIII. — On the Planet Mars. By James Nasmyth^ Esq., 

 C.E. In a Letter to Joseph Sidebotham, Esq. 



Eead March 24th, 1863. 



During the months of September and October last, when 

 the planet Mars was favourably situated for observation, I 

 had, on two or three occasions, the good fortune to obtain 

 some fine views of him. 



Under the impression that a few remarks on the aspect 

 of the planet may interest you and some of the Members 

 of the Manchester Literary and Philosophical Society, I 

 have sent you, along with this, a rough but faithful drawing 

 (see Plate X.) of the aspect of the planet, as revealed to me 

 by the aid of my 20-in. diameter reflecting telescope. 



One of the most striking and interesting features was 

 the patch of snow (?) situated near the south pole of the 

 planet. I use the term ^^ patch ^^ as most expressive of its 

 appearance. It was so distinct and definite as to appear 

 like a white wafer laid on the pole of a globe ; and what 

 contributed much to this distinct and definite aspect was 

 the remarkable contrast between its tint of pure white and 

 a brown-grey tint in the parts immediately surrounding it. 

 I have endeavoured, as carefully as I can, to represent this 

 in the accompanying drawing. The " patch "-like aspect 

 of this feature was enhanced by the impression of a cliff- 

 like edge to it, which I have also endeavoured to convey in 

 the drawing. The brilliant white of this south pole snow- 

 patch, in contrast with the dull and ruddy tint of the rest 

 of the planet contiguous to it, forcibly conveyed the im- 

 pression that the patch in question was the snow of the 

 south arctic pole, then in its summer position. 



