1865.] Prof. Phillips on the Planet Mars. 43 



the subjects then suggested for consideration was the permanence of the 

 main features of light and shade which had been recognized by many ob- 

 servers. Another question requiring attention referred to the fogginess or 

 seeming cloudiness of the planet, also noticed by many observers, some of 

 whom represented what might be thought effects of currents in the atmo- 

 sphere round him. Again, it was a matter for further research whether 

 the colours of what we suppose to be land and sea (the reddish hue of the 

 land, and the grey aspect of the sea) were capable of explanation by any 

 peculiarity of the soil or atmosphere, and whether, from the phenomena of 

 snows visible about the poles and elsewhere, the climate of Mars could be 

 estimated on trustworthy grounds. 



My observations are too few to furnish answers for all these questions ; 

 but I have something to say in reply to some of them, though the distance 

 of Mars from the Earth during the late opposition was too great to allow 

 of such close scrutiny as in 1862. 



First, then, in respect of the permanence of the main features of the 

 planet. I submit several drawings* made between the 14th November and 

 1 3th December (both inclusive), the dates being marked on each, for com- 

 parison with others made in 1862, partly by Mr. Lockyer, partly by my- 

 self ; from which it will immediately appear that no appreciable change 

 has occurred in the main outlines of land and sea, in the longitudes observed. 

 A certain fogginess has been noticed, especially on the 18th and 20th 

 November, such as does not commonly occur with Jupiter or Saturn ; but 

 it seemed to be due to no essential circumstance of the planet, for it grew 

 less and less as the observation approached the meridian. 



The colour of the larger masses of land is the same as formerly observed, 

 but fainter from distance ; and the sea is grey and shadowy, but without 

 the very distinct greenish hue which was noticed in 1862. Finally, the 

 snows round the south pole appeared much less extensive than in 1862, 

 and were not really observable with distinctness except on a few evenings. 

 Snowy surfaces, scarcely more denned, but much more extensive, were 

 observed in parts of the northern regions, not immediately encircling the 

 pole (which was invisible), but in two principal and separate tracts estimated 

 to reach 40 or 45 from the pole. On one occasion (30th November) two 

 practised observers (Mr. Luff and Mr. Bloxidge) noticed with me one of 

 these gleaming masses of snow, very distinct so much so, that, as happened 

 with the south polar snow in 1862, it seemed to project beyond the circular 

 outline an optical effect, no doubt, and due to the bright irradiation. 

 This white mass reached to about 40 or 45 from the pole, in the meridian 

 of 30 on my globe of Mars. Another mass was noticed on the 14th and 

 18th November, in long. 225, and extending to lat. 50. In each case 

 the masses reached the visible limb. 



The small extent of the snow visible at the further pole may be truly 

 the effect of the position of the planet. If we remember that on this 

 occasion the axis of Mars was nearly (within about 6 or 8) at right angles 



* Preserved for reference in the Archives ; an equatorial projection is given in Plate II. 



