PATER'S CHATS WITH THE BOYS.

Otago Witness, Issue 2785, 31 July 1907, Page 85

PATER'S CHATS WITH THE BOYS.

A WORD OR TWO ON NEPTUNE. tast week I said I intended writing a word or two on Neptune, but would not add to our editor's troubles, knowing he had to find room for so much. "I suppose the same remark pretty well applies to this week, for there is the parliamentary news to find room for. I have "sat" in Parliament, but not as. a mem- ! ber, and would just as soon spend time in purgatory as in listening to sine-tenths of what is said by our M.H.B.'s. ' Just another word, however, on Mars. I Two or three years ago I wrote a chat or two on tbe moon, and stated that gravity there was about one-sixth of what it- is j with us; this means that a pound of ] sugar on the moon would weigh six with us. Sir Robert Ball says that on Mars it is about one-half what it is with us. I read, too, the other day that the average temperature on Mars may be as high as 47deg Fahrenheit ; and that, owintg to atmospheric pressure being less there, water boils at llldeg instead of 212, as with us. NEPTUNE. As far as I am aware, the best brief account of Neptune is written by the astronomer I have mentioned, and I have picked out Neptune because, as far as is known, he is the frontier planet of two solar systems. Sir Robert Ball says that the discovery of Neptune was "so extraordinary that the whole annals, of science may be searched in vain for a parallel," and that he "was revealed by profound mathematical research rather than by minute telescopic investigation." Now, what this mathematical research is I have not the ability to explain, except in a general way. We know that the planets attract each other in proportion to their distance and mass ; and astronomers noticed that, after making allowances for the inter-influence between Saturn and Uranus, there was some other influence leading them astray, so they set to work, and were able to locate the position of this disturbing factor. Then the telescopes were brought into - requisition. Of course, there was the risk that the disturbing body might be of such faint brightness as not to be easily picked vp — and there were other chances against the astronomer. All possible contingencies were allowed for, and at last, on the

night of the 23rd of September, 1846, id th<s field of the multitude of stars made visible by the telescope, the wanderer was singled out. -This is how Sir Robert describes this astronomical triumph :— "Instantly the name of Le Verrier rose to a pinnacle hardly surpassed by that"* of any astronomer of any age or country* The circumstances of the "discovery werej highly dramatic. We picture the great astronomer .buried in profound .meditation for many months ; his eyes are bent, not on the stare, but on. his calculations. No

f telescope is in his hand ; the human intellect is the instrument he alone uses. With, patient labour, guided by consummate mathematical artifice, he manipulates his columns of figures. He attempts one solution after another. In each he learns something to avoid; by each he obtains some light to guide him in his future labours. At length he begins to see harmcny in these results where before there was discord. Gradually the clouds dis^ perse, and he sees with a certainty little short of actual vision the planet glittering in the far depths of space. He rises from his desk and invokes the aid of a practical astronomer j and lo ! there is the planet in the indicated spot. The annals of science present no such spectacle as this. It was the most triumphant proof of the law of universal gravitation." And what size 's this planet which had eluded the astronomers down the ages and had so recently been located by mathematics and then made visible? Just a trifle of 35,000 miles in diameter, or more than four times that of our earth, and making 90 of it in size. Its density however, is only about one-fifth of our globe. But it_goes on a pretty extensive tour on its journey round the sun, for it rs 2780 million miles away from the sun, which keeps it in leading strings, so it must travel about 17,500 millions of miles in making a complete jircvrft. Our earth is' a fair traveller, for she goes about 600 millions of miles in circling the sun ; but she is nowhere beside Neptune. He, however, moves more leisurely, because it takes him about 165 yeans to make his annual round. So far, only one moon has been discovered, and, as it goes around in six days, that is the length of a month on Neptune. What the length of a day is has not yet been found out, I think. How would you like to live 165 of our years before being in reality a year old? What about having five new moons where we have just one? Perhaps after these two chats on Mars and Neptune you may wish to make a further acquaintance with the heavenly bodies. I hope you will. Since writing the above I have come acioss an article on Mars, and from it make the following extracts : — MARS DYING OF THIRST. — Startling Theory of Its Great Canals. — "The geometrical lines seen on the planet Mars are canals constructed by superhuman intelligence for the purpose of distributing water over the planet." This amazing suggestion is made by Professor Lowell, the Boston Professor of Astronomy. Is Mars, then, in a dying condition, fated in the long 1 run to die of thirst? Have her people been forced to dig huge irrigating canals from the polar regions to the equator to prevent death from thirst and starvation? Is a great tragedy of space going on before our eyes? Professor Lowell believes that, unlike the earth, Mars is apparently in straits for water, and has to draw upon its polar reservoir for its annual supply. ITierefore, to the melting of the polar cap and the transference of the water thus annually set free through vast canals thousands of miles long the people of Mars owe their salvation. With the disappearance of the water from the surface of the planet the Mai* tians will die. Tear by year Professor Lowell has watched and carefully noted the annual melting of the southern polar cap and the slow flushing and darkening of the planet's surface as the water was distributed through the various canals and consequent zones of vegetation sprang into life. This darkening always begins in a thin blue belt extending along the edge of the great snowfields at the southern pole. In one of his pamphlets on Mars, Professor Lowell says of this phenomenon: "As the season advanced and the snow cap diminished, its dark girdle decreased in breadth, with fluctuations dependent, doubtless, on the draining capacity of the ground. In August it eLowed as a slender dark thread. "That it was water is practically beyond a doubt. That it was of the colour of water, that it so faithfully followed the melting of the snow, and that it subsequently vanished are three independent facts mutually confirmatory to this conclusion. "We may therefore conclude that the seas of Mars are probably midway in evolution between the seas of earth and the seas of the moon. No longer bodies of water, they have not yet become barren ocean beds, but are in that halfway stage erf the process when their low level helps them catch what water still voyages upi>n the planet' 6 surface, though they have long since parted with their own."