I have applied to the different features the names of those observers
who have studied the physical peculiarities presented by Mars. Mr.
Dawes' name naturally occurs more frequently than others. Indeed, if I
had followed the rule of giving to each feature the name of its
discoverer, Mr. Dawes' name would have occurred much more frequently
than it actually does.

On account of the eccentricity of his orbit, Mars is seen much better in
some oppositions than in others. When best seen the southern hemisphere
is brought more into view than the northern because the summer of his
northern hemisphere occurs when he is nearly in aphelion (as is the case
with the Earth by the way).

The relative dimensions and presentation of Mars, as seen in opposition
in perihelion, and in opposition in aphelion, are shown in the two rows
of figures.

In and near quadrature Mars is perceptibly gibbous. He is seen thus
about two months before or after opposition. In the former case, he
rises late and comes to the meridian six hours or so after midnight. In
the latter case, he is well seen in the evening, coming to the meridian
at six. His appearance and relative dimensions as he passes from
opposition to quadrature are shown in the last three figures of the
upper row.

Mars' polar caps may be seen with very moderate powers.

I add four sets of meridians (Plate 6), by filling in which from the
charts the observer may obtain any number of views of the planet as it
appears at different times.