182 TJw Planet Mars : a Fragment. 



was posterior to the carboniferous lime, and anterior to the 

 gres rouges of South America. 



" 7, 8, 9. Elevations of Schist Rocks op South Ame- 

 rica, of which M. Pissis distinguishes three kinds, all very- 

 old/' 



M. Pissis considers that each movement of elevation was 

 characterized by the emission of a particular rock, which takes 

 the place of a characteristic fossil in the determination of its 

 age. 



THE PLANET MARS : A FRAGMENT. 



BY THE REV. T. W. WEBB, M.A., F.K.A.S. 



(With a Coloured Plate.) 



" I give the first watch of the night 

 To the red planet Mars." — Longeellow. 



From the tenor of some remarks which appeared in the 

 present publication previous to the late opposition of Mars,* 

 the idea may possibly have been entertained that the author 

 of them intended to avail himself of that opportunity to make 

 some detailed observations upon the aspect of this interesting 

 planet. The impression would have been well-founded. I 

 had purposed to undertake a careful examination of the 

 physical features of Mars, as far as they would be brought out 

 by the power of an excellent 5^ inch object-glass, and secur- 

 ing, if possible, a delineation of as much of his surface as would 

 at that time be exposed to view. It was indeed to be expected 

 that the same task would be taken in hand by far superior 

 observers, armed with much more powerful instruments, and, 

 in part, favoured by purer skies ; yet it did not seem to follow 

 that a more humble attempt would be superseded, or would 

 necessarily prove entirely useless ; for it has not imfrequently 

 been the cafe that inferior observations have found a place 

 for themselves in that general accumulation of materials from 

 which our final deductions have to be inferred. The peculiarly 

 valuable investigations of Beer and Miidler were long carried 

 on with :ni object-glass of not moro than A<\ inches aperture; 

 and a quotation which they have employed will furnish an 

 appropriate motto for any similar case: — 



" Quod potui fed ; faciant meliora potentes." 



The execution of my design proved indeed far more defec- 

 tive than 1 had anticipated. Absence from home, cloudy 

 weather, ;i7id seasons of bad definition conspired to interpose 



* Intellectual Observed, viii. 132. See also xi. 376. 



