Ascraeus Lucus, [331];
embraced by the double Gigas, [257].
Astaboras, connection with Lucus Ismenius, [260-263].
Atmosphere, of Mars, [62], [63], [71], [78], [79], [87];
shown to exist, [80], [82], [83], [84], [163], [167];
rare, [85], [86], [162], [167];
effect on temperature, [80];
constituents of, [162], [164], [166], [168].
Autumn, length of Martian, in northern hemisphere, [35], [48];