THE PLANET VENUS.

Grey River Argus, Volume XV, Issue 1953, 9 November 1874, Page 2

THE PLANET VENUS.

The following observations c bh #the, beautiful planet, which, is shining briluV lantly in the western heavens every evening, are taken -from Proctor's "Other Worlds than Ours," one of the latest, works on astronomy. 1 1./,: — ./, The peculiarities which characterise? Venus are for the most part similar.. in* kind'tb those; we had to-consider; in the? case of Mercury. ; Butr-at the. ;Onts|t| of 7 our inquiries into the physical habitudes-, of this most beautiful planet, we? must, point to the striking resemblance whichi it "bearSj in some respects, to our own ; earth. ; So far, indeed, lastelescopicr and physical researches have yet led "usj~|the planet. Marsi as we_;shall presently see^ ap- | pears to exhibit habitudes more closely corresponding to those/we are apt , to.consider essential to the" wants of living'creatnres. But in size,- situation, and in density, in the length of her* seasons and of rotation, in the figure of her orbit, and in the amount of light' and heat she receives from the sun, Venus bears a more striking resemblance to the Earth J;hap, ; any orb within the solar system. lii fact, there is no other .pair of planets between which so many analogies can be traced as between! Venus and the Earth; ffJJranus and Neptune are similar in many respects, but they differ, at. least, as, many. Jupiter arid. Saturn are, in a ! sense, the brother giants .of the solar.scheme, while the dwarf orbs, Mars and Mercury, present many striking points of similarity ; but between neither of these pairs «an we I trace so many features ( of. resemblance as ! those which characte^isS'the twin 'planets | Venus and Terra, t , .while the features of dissimilarity 1 in either pair are perhaps, even more obvious than the points of resemblance.'Had Venus but a; moon, as the earth has, we might doubt whether, -in the whole universe, .two orbits exist which are so strikingly similar T t6 each Other.' "r- ; ■' ''■ ■ ■■■■■• V. ■:■-■ v, ; : . : .r. ■•■'; And here we may vpauseior a ; moment to consider one of the. most perplexinjg enigmas that has ever been presented to astronomers. Are we indeed certain that Venus has no moon ? The question seems a strange one, when it is remembered that .year after year Venus has been examined by the most eminent modern observers, armed with telescopes of the most exqui-

site defining power, without any trace of „ a companion orb being noticed. Nor, indeed, can any reasonable doubts be entertained respecting the moonless condition of Venus, by those who appreciate the character of modern telescopic observations. And yet, if I had begun this paragraph by stating the evidence in favor of the existence of a satellite, I believe that nearly every reader would have come to the conclusion that most certainly the Planet of Love has an attendant orb. They are not amateur observers only who have seen a moon attending on Venus, but such astronomers as Cassini and Short, the latter with two different telescopes and four different eye-pieces. Four times between the 3rd and 11th May, 1761, Montaigne saw a body near Venus, which presented a phase similar to that of tbe planet, precisely as a satellite would have done. From these observations M. Baudouin deduced for the new star a diameter of about 2000 miles, and a distance from Venus nearly equal to that which seperaies the moon from the earth. In March, 1764, again "Rodkier saw the enigmatical companion ; Horrebow saw it in a few days later ; and Montbaren saw it in varying positions on the 15th, 28th, and 29 th March. Lastly, Scheuten, who witnessed the transit of Venus in 1761, declares that he saw a satellite accompany • Venus across the face of the sun. So that we cannot be greatly surprised that even so skilful an observer .as the late Admiral Smyth was disposed to believe the existence of a satellite of Venus. " The contested satellite is i perhaps," he remarked, "extremely miuute, while some parts of its body may be less capable of reflecting light than others ; and when the splendour of its primary and our inconvenient station for watching it are considered, it must be conceded that, however slight the hope may be, the search ought not to be relinquished." Venus has a year of 224 days 17 hours, very nearly, and her distance from the sun, which varies iittle during the course of a year, is somewhat less than threefourths of that which separates the sun from us. Her day is about thirty-five minutes shorter than ours, and her globe somewhat smaller than the Earth's. The arctic regions- of Venus extend within 15deg. or her equator (if the axis is really bowed as supposed), while the tropics extend within 15deg. of her poles — so that two zones, larger by far than the temperate zones of our earth, belong both to hel arctic and to her tropical regions. It is difficult to say whether her equatorial, her polar, or her artico-tropical regions would be, to our ideas, the least pleasing portion of her globe. An inhabitant of the regions near either pole has to endure extremes of heat and cold, such as would suffice to destroy nearly every race of living beings subsisting upon the Earth. During the summer, the sun circles continually close to tbe point overhead, so that, day after day, he pours down his rays with an intensity of heat and. of light exceeding nearly twofold the midday light and heat of our own tropical sun. Only for a short time, in autumn and in spring, does the sun rise and set in these regions. A spring or autumn day, like one of our days at those seasons, lasts about twelve hours ; but the sun attains at noon, in spring or autumn, a leight of only a few degrees above the horizon. Then presently comes on the tefrrible winter, lasting about three or four months, but far more striking in its characteristics even than the long winter night of our polar regions. For, near our poles, the sun approaches the horizon at the hour corresponding to noon; and though he does not show his face, he yet lights up the southern skies with a cheering tvrilight glow. But during the greater part of tie long night of Venus's polar regions, the sun does not approach within many degrees of the horizon. Kay, he is farther below the horizon than the midnight winter sun of our arctic regions. Thus, unless the skies are lit up with auroral splendours, an intense darkness prevails during the polar winter, which must add largely to the horrors of that terrible season. Certainly, none of the humanraces upon our Earth could bear the alterations between these more than polar terrors and an intensity of summer heat far exceeding any with which we are familiar on earth. Let us see whether the equatorial regions are more pleasing abodes In these parts of Venus there are two summers, corresponding to the spring and autumn of the polar regions. At these seasons, the sun rises day after day to the point overhead, and the weather corresponds for a while to that which prevails in the tropical regions of our own earth. But between these seasons the sun passes away alternately to the northern and southern skies. During the season corresponding to summer, he is above the horizonnearlythroughoutthe.twenty-three and a quarter hours of Venus's day ! but * he attains no great elevation, travelling always in a small circle close around the northern pole. During the season corresponding to winter, he is above the horizon only a very short time each day, and is always close to the south, attaining only an elevation of a few degrees at noon. Thus we have the following curious succession of seasons :— At the vernal equinox a summer much warmer than our tropical summers ; about fifty-six days later, or at the summer solstice, weather resembling somewhat the spring of our temperate zones, only that the night is exceedingly short ; yet fifty-six days later there is another summer, as terrible as the former ; and lastly, at the winter solstice, the days are shorter and the cold probably more intense than in the winter of places near our arctic circles. In such regions the contrasts, rather than either of the extremes of climate, would be most trying to terrestial races ; and it is scarcely too much to say, that no races subsisting upon our earth could possibly endure such remarkable changes, succeeding each other so rapidly. Lastly, the beings who inhabit the wide zones which are at once tropical and arctic haye climates ranging between the two limits just considered. If they are near the equatorial regions they suffer from all the vicissitudes of the equatorial climate, with this further tribulation that in midwinter they do not see the sun even at mid-day — a circumstance by no means compensated (according to our ideas) by the fact that near the summer solstice the sun does not set. If they are near the polar regions they have a summer even more terrible than the polar snmmer, and a winter scarcely less dreary and severe. Gravity at the surface of Venus is to nearly equal to terrestrial gravity that the difference is altogether insufficient to .introduce any noteworthy effects. The

delicate adjustment of the sap nassagps of plants to the force of terrestrial gravity, which Dr. Whewellnoticesin bi*"BriiigewaterTreatise," migbtindeed be disturbed if the earth's gravity were suddenly mac c equal to that of Venus. But it would be strangely to limit our conception of nature's powers of adaption to suppose that therefore there can be no vegation on Venus resembling that with which we are familiar. Venus is the only planet the extent of whose" atmosphere has been carsfully estimated. If Venus had no atmosphere, she would present, when horned, a semicircular convexity ; whereas the refractory effects of an atmosphere, by causing the stm to illumine rather more than a full hemisphere, would tend to lengthen her horns. It has been found that her convexity when she is horned exceeds a semicircle, and from the observed extent of this excess, it has been calculated that her atmosphere is so far more extensive than ours aa to make its refractive effects on a body near the horizon about onethird greater. So that as this is about the proportion in which the diamter of the sun as seen from Venus exceeds that which he presents to us the inhabitant of Venus like the inhabitant of our earth, see 3 the sun fully raised above thg horizon at the moment when, but for refraction, his orb would be just concealed beneath it. Of the constitution of the atmosphere of Venus we know little. The spectrum of her light shows the dark lines which belong to the solar spectrum, and the Padre Secchi has noticed certain faint lines, which seem to indicate' the presence of aqueous vapour in the atmosphere of the planet. The same observer finds, in the strengthening of the nitrogen lines near the F line of the spectrum, evidence that the atmosphere of Venus is constituted very similarly to the air we breathe. On the whole, the evidence we have points very strongly to Venus as the abode of living creatures not unlike the inhabitants of earth. With the sole exception of the inclination which has been, without sufficient evidence, assigned to the planet's equator, I can see nothing which can reasonably be held to point to an opposite conclusion. Certainly the strong light which the sun pours upon Venus need least of all be objected to, since, if there is one adaptive power which Nature exhibits more clearly than another, it is that by which the various creatures we are acquainted with are enabled to live in comfort under all degrees of light, from the obscurity in which the mole pursues his subterranean researches to the blazing light of the noon-day sun towards which (in fable, if not in fact) the eagle turns his unshrinking eyes.