The
variety in this coloring is in part of meteorological origin, in part it
may depend on the diverse nature of the soil, but upon its real cause
it is not as yet possible to frame any very well grounded hypothesis.
Nevertheless, the cause of this predominance of the red and yellow tints
upon the surface of ancient Pyrois is well known.[A] Some have thought
to attribute this coloring to the atmosphere of Mars, through which the
surface of the planet might be seen colored, as any terrestrial object
becomes red when seen through red glass. But many facts are opposed to
this idea, among others that the polar snows appear always of the purest
white, although the rays of light derived from them traverse twice the
atmosphere of Mars under great obliquity. We must then conclude that the
Arean continents appear red and yellow because they are so in fact.
Besides these dark and light regions, which we have described as seas
and continents, and of whose nature there is at present scarcely left
any room for doubt, some others exist, truly of small extent, of an
amphibious nature, which sometimes appear yellowish like the continents,
and are sometimes clothed in brown (even black in certain cases), and
assume the appearance of seas, whilst in other cases their color is
intermediate in tint, and leaves us in doubt to which class of regions
they may belong. Thus all the islands scattered through the Mare
Australe and the Mare Erythr?um belong to this category; so, too, the
long peninsula called Deucalionis Regio and Pyrrhae Regio, and in the
vicinity of the Mare Acidalium the regions designated by the names of
Baltia and Nerigos.
Pages:
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207