The Planet Mars : a Fragment. 191 



directed — appears to be satisfactorily cleared up. Without 

 seeking confirmation from the opinions of Herschel and 

 Schroter, or referring to the obvious deviation from the forms 

 given by Beer and Madler, the conclusion would naturally fol- 

 low from my observations alone. The reader may notice seve- 

 ral instances of diversity, due probably to this cause ; but two 

 may be especially pointed out — the varying aspect of the north 

 or narrow end of the dusky fan, which frequently and unmis- 

 takeably appeared pointed, but occasionally more open, espe- 

 cially in Fig. V., on one of the finest nights of definition ; and 

 the contrast between Figs. XIV. and XV., from which, as both 

 were careful observations, it is fair to conclude, either that the 

 narrow isthmus* crossing obliquely the dark spot was laterally 

 moveable, or that in the latter instance the west end of the spot 

 (B in the planisphere) was temporarily obscured. Still, were 

 this dependent merely upon my own testimony, I might feel 

 less confident, but Lockyer's most careful observations, corro- 

 borated by Dawes, have led him to the same inference ; Lassell 

 has found recurring phases so far from uniform as to infer ' c the 

 transit of clouds of great extent, density, and variety of form ;" 

 Groves had come to a similar conclusion ; and Phillips, from a 

 comparison of his own drawings with those of the Earl of Eosse 

 and Lockyer, is even led to entertain u serious doubts whether 

 any of our drawings of those" southern " parts are much to be 

 trusted as representing permanent physical boundaries. Nor 

 should this," he adds, " be thought surprising ; owing to the 

 high inclination of the axis of Mars to the plane of his orbit, 

 the regions round each pole are presented alternately to the 

 sun through periods somewhat less than our whole year. The 

 effect is seen in the vast outspread of snows round the cold pole, 

 and the contraction of those white sheets to a small glittering 

 ellipse round the warm pole. The enormous transfer of mois- 

 ture from one hemisphere to the other while the snows are 

 melting round one pole and growing round the other must 

 generate over a great part of the planet heavy storms and 

 great breadths of fluctuating clouds, which would not, as on 

 the quickly rotating mass of Jupiter, gather into equatorial 

 bands, but be more under the influence of prominent land and 

 irregular tracts of ocean." 



* This division between D and E does not appear in Beer and Miidler : it 

 may be doubted whether from want of optical power : with me it was a frequently 

 recurring feature, traceable more or less distinctly in six sketches between October 

 9 and November 24 When Fig. XV. was drawn, I was inclined to believe that a 

 steadier air might havo shown anothor bright but very narrow partition just to 

 the right of it. November 17, when the figure was intermediate between X I V. and 

 XV., a similar impression recurred, and even a surmise of another bright longitu- 

 dinal streak connecting the two obliquo ones ; but these additions were extremely 

 uncertain. 



