s
to tilt each pole towards the sun, and the other from it, alternately,
thus producing what by courtesy we may call the seasons in Womla?"

"Yes."

"Well, judging from the observations I have made, we were probably right
so far; but if you recollect, I accounted for the mysterious daily rise
and set of the sun, if I may use the words, by changes in the density of
the atmosphere bending the solar rays, and making the disk appear to
rise and sink periodically, though in reality it does nothing of the
kind. A similar effect is well-known on the earth. It produces the
'after glow' on the peaks of the Alps when the sun is far below the
horizon; it sometimes makes the sun bob up and down again after sunset,
and it has been known to make the sun show in the Arctic regions three
weeks before the proper time. I had some difficulty in understanding how
the effect could take place so regularly."

"I think you ascribed it to the interaction of the solar heat and the
evaporation from the surface."

"Quite so. I assumed that when the sun is low the vapours above the edge
of the crater and elsewhere cool and condense, thus bending the rays and
seeming to lift the sun higher; but after a time the rays heat and
rarefy the vapours, thus lowering the sun again. It seemed a plausible
hypothesis and satisfied me for a time, but still not altogether, and
now I believe I have made a discovery."

"And it is?"

"That Venus is a wobbler."

"A wobbler?"

"That she wobbles--that she doesn't keep steady--swings from side to
side. You have seen a top, how stiff and erect it is when it is spinning
fast, and how it wobbles when it is spinning slow, just before it
falls. Well, I think something of the kind is going on with Venus. The
earth may be compared to a top that is whirling fast, and Venus to one
that has slowed down. She is less able than the earth to resist the
disturbing attraction of the sun on the inequalities of her figure, and
therefore she wobbles. In addition to the slow swinging of her axis
which produces her 'seasons,' she has a quicker nodding, which gives
rise to day and night in some favoured spots like Womla."

"After all," said I, "tis a feminine trait. _Souvent femme varie._"

"Oh, she is constant to her lord the sun," rejoined Gazen. "She never
turns her back upon him, but if I have not discovered a mare's nest,
which is very likely, she becks and bows to him a good deal, and thus
maintains her 'infinite variety.'