evidence of the spectroscope
shows that water vapour is there present.

If there be oxygen in the atmosphere of Venus, then it would seem
possible that there might be life on that globe not essentially
different in character from some forms of life on the earth. No doubt
the sun's heat on Venus is greatly in excess of the sun's heat with
which we are acquainted, but this is not an insuperable difficulty. We
see at present on the earth, life in very hot regions and life in very
cold regions. Indeed, with each approach to the Equator we find life
more and more exuberant; so that, if water be present on the surface of
Venus and if oxygen be a constituent of its atmosphere, we might expect
to find in that planet a luxuriant tropical life, of a kind perhaps
analogous in some respects to life on the earth.

In our account of the planet Mercury, as well as in the brief
description of the hypothetical planet Vulcan, it has been necessary to
allude to the phenomena presented by the transit of a planet over the
face of the sun. Such an event is always of interest to astronomers, and
especially so in the case of Venus. We have in recent years had the
opportunity of witnessing two of these rare occurrences. It is perhaps
not too much to assert that the transits of 1874 and 1882 have received
a degree of attention never before accorded to any astronomical
phenomenon.

The transit of Venus cannot be described as a very striking or beautiful
spectacle. It is not nearly so fine a sight as a great comet or a shower
of shooting stars. Why is it, then, that it is regarded as of so much
scientific importance? It is because the phenomenon helps us to solve
one of the greatest problems which has ever engaged the mind of man. By
the transit of Venus we may determine the scale on which our solar
system is constructed. Truly this is a noble problem. Let us dwell upon
it for a moment. In the centre of our system we have the sun--a majestic
globe more than a million times as large as the earth. Circling round
the sun we have the planets, of which our earth is but one. There are
hundreds of small planets. There are a few comparable with our earth;
there are others vastly surpassing the earth. Besides the planets there
are other bodies in our system. Many of the planets are accompanied by
systems of revolving moons. There are hundreds, perhaps thousands, of
comets. Each member of this stupendous host moves in a prescribed orbit
around the sun, a