It was clear that even in their amusements the Martians were
scientific; for here outlined in glowing colours was the familiar
geometrical figure of an equilateral triangle inscribed within a circle,
perfectly worked out on a most gigantic scale, and very pretty it was.
Quickly, another triangle was formed across the first one, the result
being a six-pointed star; and so on with several other more elaborate
geometrical figures. The rapidity and certainty with which these
air-ships took up the requisite positions and showed their coloured
lights in the appropriate places was marvellous to see.

After about a dozen geometrical figures had been formed there ensued a
rapid and bewildering movement of the ships towards the southern vault
of the sky. Coloured lights flashed and whirled about in what, for a few
minutes, seemed chaotic confusion, then suddenly the chaos was
transformed into order. The vessels formed up in long rows one below the
other, each row having one distinctive colour: a little movement of the
ships from the centre to each end, in a downward direction, and the
straight rows were transformed into complete semicircles concentric with
each other, their bases seeming to reach the ground. Then they closed
together, and lo! right across the sky shone a perfect representation of
a rainbow (an extremely rare phenomenon upon Mars) glowing in brilliant
light, with every tint and _nuance_ accurate, and a thousand times
brighter than any rainbow we had ever seen. It was magnificent!

Further rapid movements followed: the semicircles were broken up; the
large vessels now being arranged in a long straight line across the sky,
with the smaller vessels in another line just below and in front of
them. The electric lamps were then instantaneously extinguished, and all
was darkness. But only for a moment; then from the top of every vessel
numerous immense pillars of coloured lights shot upwards into the sky.

We gazed at this in some perplexity, wondering what it all meant, as the
design gradually developed to its completion. Then John touched my arm,
excitedly exclaiming, "Look, Professor; it is the spectrum of the sun!"
Yes, that it was, and never had we gazed upon such an immense and
glorious spectrum. We pointed out to each other the lines of hydrogen,
sodium, strontium, and many others, all of which were truly depicted,
both in colour and position. These lines were formed by the lights of
the smaller vessels shown ag