Notwithstanding its much greater area the southern snow-cap melts to a greater extent than the northern snow-cap does, owing to the intensity of the heat at the melting period. 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°. In the year 1894 it disappeared entirely! The summer must have been unusually hot. 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. * * * * * We had arrived upon Mars on the 24th of September 1909, according to terrestrial reckoning; but according to the Martian date it was then the 26th of June in the southern hemisphere, where Sirapion, our landing-place, is situated. The season was, therefore, midsummer, and as Sirapion is in latitude 25° south and in the sub-tropical zone, the temperature was fairly high. The mornings were much more clear and brilliant than those on our earth; the warmth and general "feel" of the air at that time reminding me very much of what it is like in the south of England between seven and eight o'clock on a hot sunny day. Those who enjoy an early morning walk know how delightful and exhilarating it becomes towards that time. There is neither chilliness nor uncomfortable heat; one feels a delightful sense of freedom and that it is good to be alive. This is really the best and most enjoyable time on a summer's day. On Mars there was rather more warmth but a greater sense of exhilaration. Of course, from near noon to about 3 P.M. it was much warmer. Usually a lovely rosy effulgence is seen in the atmosphere in the mornings and evenings. As a rule, sunrise and sunset effects are much more ethereal and more beautiful than those on the earth, the tints being more delicate and the whole appearance of the sky less broadly marked. It is as the difference between the crude broad effects of a coloured poster and the delicate effects of a highly-finished painting. What, in our sunsets, would appear a deep golden colour appears on Mars as a delicate pale gold, merging into bright silver. What with us is a carmine or deep rose, in Martian skies becomes a beautiful rose-pink; whilst the darker, or Indian, red seen for some time at the latter period of our sunsets is carmine in the Martian sky, and Indian red only appears just at the last.