HARD WICKE' S SCIENCE- G OSSIP. 



Enough, our walk has made us hungry, and 

 beside us on the grass are two limestone instruments 

 ground to the shape of carpenter's chalks, one of 

 them is sharpened like a chisel and the other one is 

 pointed. Having the customary outline of a shell, 

 they both fit nicely to the finger and thumb, and 

 either would serve equally well as a knife. The 

 silent mountains that furnished them jut up into the 

 clear sky-like lofty walls and down from their crests 

 that frown aloft like feudal towers, the winter 

 avalanches have been mercilessly crashing. Around 

 us here and there are strewn incisive stone bomerangs, 

 more or less fish-shaped, so as to fit into the palm of 

 the hand, and having a thumb-hole. Here is one on 

 which are scratched, if we mistake not, the Roman 

 figures for twelve, and which should go sky-high. 

 Where are gone the bears that came tumbling in 

 their antics down those perpendicular slopes, the 

 lynxes that glared and sprang from the broken fir- 

 boughs, the boars that rustled and grunted among 

 the beech-mast, the battling stags that drank by 

 moonlight and bounded away at the famished howl 

 of the wolves. Truly, this sweetly pretty valley is 

 most deserted, for it is deprived alike of good and 

 evil, and no voice now whispers in the ear, Arise, 

 slay, flay, and eat. 



IS THERE VEGETATION IN MARS? 



ON page 376 of M. Flammarion's "La Planete 

 Mars," in a [foot-note, the author quotes from 

 M. Trouvelot as follows: "Les grands continents 

 de l'hemisphere nord sont occupe's par des taches 

 grisatres plus ou moins faibles, qui sont dissemi- 

 nees sur eux. A en juger d'apres les changements 

 que j'ai vu subir a ces taches, d'annee en annee, 

 on pourrait croire que les taches grisatres vari- 

 ables sont dues a. une vegetation martienne 

 qui subit l'alternative des saisons." More through 

 curiosity than with any expectation of arriving 

 at any results of scientific importance, I deter- 

 mined to take M. Trouvelot's suggestion as correct, 

 and endeavour to ascertain the laws according to 

 which this vegetation varied with the seasons. I 

 expected to find these variations so contradictory 

 that no definite laws could be deduced. To my 

 surprise, this was not the case ; I saw that I was 

 arriving at conclusions, which, although very different 

 from my preconceived ideas, were yet perfectly con- 

 sistent, and showed a remarkable analogy with the 

 variations of terrestrial vegetation. I then determined 

 to investigate the matter more carefully, and as a first 

 step, I drew up a calendar for Mars, covering the 

 terrestrial years 1857 to 1893, by the aid of which I 

 could at once assign any observation to its precise 

 period in the Martian year. The results were, as I 

 have said, surprisingly definite ; in fact, when I have 

 made a mistake in taking down the date of an 



observation, I could generally discover that a mistake 

 had been made, by the discrepancy between the 

 observed appearances, and those which I would 

 expect from the date. My preconceived ideas with 

 regard to the Martian vegetation, were, that it was 

 probably reddish or fuscous in colour, and that the 

 laws of its seasonal variation were probably very 

 different from those of our own. The results which I 

 arrived at were just the contrary • that the colour 

 was some dark tint, appearing dark grey, or nearly 

 black, when seen in mass, and from a distance, like 

 our own, and not improbably a dark green ; and 

 that it resembled our own very closely in the way it 

 varied with the seasons. It has been held that the 

 Martian continents owe their reddish colour to some 

 kind of vegetation, and therefore that the Martian 

 vegetation is probably reddish. I do not assert that 

 the Martian continents are not covered with a reddish 

 vegetation ; I only say (1) I can find no proof that it 

 is so ; (2) this red vegetation appears constant and 

 does not change with the seasons ; (3) it shows no 

 tendency to prefer sites near water. 



The dark-coloured vegetation is not dispersed over 

 the entire land area ; it is confined to places all pre- 

 sumably near water ; these are, (1) the canals which 

 appear to be ravines with probably a river at the 

 bottom, but certainly not all water, except in a few 

 cases ; and (2) the banks of certain inland lakes, 

 especially Lake Niliacus, Lake Tithonius, and Terby 

 Sea. The way in which it varies with the seasons is 

 different in different latitudes, like our own. Thus, 

 take the northern temperate, say N. lat. 45 . 

 The course of variation is as follows. During the 

 winter no trace of vegetation is perceptible. At a 

 Martian date corresponding to the 12-15 March the 

 first signs appear. These early traces are of a reddish 

 or yellowish brown. (Our own woods often assume 

 a reddish-brown colour in early spring, when seen 

 from a distance.) This colour persists through the 

 early part of April, but by the end of May, the dark 

 green or grey coloration has been assumed, and it 

 remains till the end of July. Early in August the 

 red colour again appears, and soon after all signs 

 disappear. This apparently corresponds to our " fall 

 of the leaf," but takes place at a comparatively earlier 

 date, corresponding to about 12-27 August. So we 

 see that the general course of vegetation resembles 

 what takes place here, but is about a month earlier. 



For the southern extratropical latitudes evidence is 

 scanty, inasmuch as there is comparatively little land 

 in the southern hemisphere outside the tropics. Such 

 evidence as there is, however, agrees with this. 

 Thus, apparently, the trees are in full leaf in 

 December, and are bare by the end of February. In 

 the tropics the laws are quite different, and not 

 nearly so definite. The vegetation seems to be a 

 mixture of the northern and southern types, with a 

 small quantity of a true equatorial type, in leaf at the 

 equinoxes, bare at the solstices. There are some 



