snow-cap

The whole of the dark areas on the planet covered at least 17,000,000 square miles, and as this was seven times the area of the snow-cap, it followed that the dark areas could not be covered with more than two inches of water.

To Mars via The Moon An Astronomical Story Mark Wicks

The writer in question had stated that the maximum area of the southern snow-cap was

To Mars via The Moon An Astronomical Story Mark Wicks

So far as can be gathered from the records of our whaling and polar expeditions, it would appear that our north polar snow-cap is from 20° to 30° in diameter when at the minimum; whilst the southern snow-cap is nearly 40° in diameter when smallest.

To Mars via The Moon An Astronomical Story Mark Wicks

The snow-cap had recently decreased rapidly, being now near its minimum and irregular in shape, for in the southern hemisphere it was now late in June.

To Mars via The Moon An Astronomical Story Mark Wicks

The south polar snow-cap is seen at the top, and as it is early June on this part of Mars, the snow-cap has become small.

To Mars via The Moon An Astronomical Story Mark Wicks

When it is spring in the northern hemisphere the winter snow-cap at the north pole will begin to melt in like manner, and the water be distributed in a similar way.

To Mars via The Moon An Astronomical Story Mark Wicks

The most noticeable new features observed were two large detached pieces of the south polar snow-cap, the altered shape of the Solis Lacus and other dark areas, numerous dark rounded spots on the dark areas, much detail along the lines of the canals, and the observation of scattered markings instead of lines.

To Mars via The Moon An Astronomical Story Mark Wicks

For this reason, our south polar snow-cap is larger than the north polar cap; and we should naturally expect to find a similar condition upon

To Mars via The Moon An Astronomical Story Mark Wicks

The northern snow-cap usually melts until the diameter is reduced to about 6°, whilst the much larger southern cap may be reduced to about 5°.

To Mars via The Moon An Astronomical Story Mark Wicks

Astronomical observation shows that this is the case, for while the northern snow-cap on Mars attains a maximum diameter of slightly under 80°, the southern snow-cap attains a maximum diameter of over 96°.

To Mars via The Moon An Astronomical Story Mark Wicks