Dr. Phillips on the Planet Mars. 323 



November and 13th December (both inclusive), the dates being 

 marked on each, for comparison with others made in 1862, partly 

 by Mr. Lockyer, partly by myself ; 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 ob- 

 served, 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 ex'tending 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 to the line of sight, while in 1862 it was ob- 

 lique (about 26°), we shall perceive that though the snow about the 

 south pole were really as extensive in 1864 as it appeared to be in 

 1862, it could not possibly appear even nearly so large, and in 

 fact could barely be seen (as it was) under the very small angle 

 which it would subtend on the limb. There may, however, have 

 been really less snow round the south pole, in consequence of the 

 longer action of the summer heat on Mars in 1864 than in 1863. 

 . The ruddy tint of the surface of the broad tracts of land is so con- 

 stantly observed in these parts as to claim to be regarded as charac- 

 teristic of some peculiarity in them — some special kind of terrestrial 

 substance for example *. On the other hand, the tint is so much 



* " In this planet we discern, with perfect distinctness, the outlines of what 

 may be continents and seas. Of these, the former are distinguished by that ruddy 

 colour which characterizes the light of this planet (which always appears red and 

 fiery), and indicates, no doubt, an ochrey tinge in the general soil, like what the 

 red sandstone districts on the earth may possibly offer to the inhabitants of 

 Mars, only more decided. Contrasted with this (by a general law in optics) the 

 seas, as we may call them, appear greenish." — Herschel's Astronomy (ed. 1833), 

 p. 279. 



