The data for determining this were taken from Dr.Oudemann's determinations given in a valuable paper on Mars issued from Mr.Bishop's observatory.

But instead of calculating Mars' presentation by the formulae there given, I found it convenient rather to make use of geometrical constructions applied to my 'Charts of the Terrestrial Planets.' Taking Maedler's start-point for Martial longitudes, that is the longitude-line passing near Dawes' forked bay, I found that my results agreed pretty fairly with those in Prof.Phillips' map, so far as the latter went; but there are many details in my charts not found in Prof.Phillips' nor in Maedler's earlier charts.
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.