at variable hours, shone when it
felt disposed, sometimes was eclipsed, or hid itself behind the clouds
when one had most need of it, or pitilessly blinded one at the very
moment one yearned for shade! Every night,--do we really realise the
full force of the inconvenience?--every night the sun commanded social
life to desist and social life desisted. Humanity was actually to that
extent the slave of nature! To think it never succeeded in, never even
dreamed of, freeing itself from this slavery which weighed so heavily
and unconsciously on its destinies, on the course of its progress thus
straitened and confined! Ah! Let us once more bless our fortunate
disaster!

What excuses or explains the weakness of the first immigrants of the
inner world is the fact that their life was necessarily rough and full
of hardships, in spite of a notable improvement after their descent into
the caverns. They had perpetually to enlarge them, to adjust them to the
requirements of the two civilisations, ancient and modern. That was not
the work of a single day. I am well aware how happily fortune favoured
them; how they again and again had the good luck when driving their
tunnels to discover natural grottoes of the utmost beauty, in which it
was enough to illuminate with the usual methods of lighting (which was
absolutely cost-free, as Miltiades had foreseen) in order to render them
almost habitable: delightful squares, as it were, enshrined and sparsely
disseminated throughout the labyrinth of our brilliantly lighted
streets; mines of sparkling diamonds, lakes of quicksilver, mounds of
golden ingots. I am well aware that they had at their disposition a sum
of natural forces very superior to all that the preceding ages had been
acquainted with. That is very easy to understand. In fact, if they
lacked waterfalls, they replaced them very advantageously by the finest
falls in temperature that physicists have ever dreamed of. The central
heat of the globe could not, it is true, by itself alone be a mechanical
force, any more than formerly a large mass of water falling by
hypothesis to the greatest possible depth. It is in its passage from a
higher to a lower level that the mass of water becomes (or rather
became) available energy: it is in its descent from a higher to a lower
degree of the thermometer that heat likewise becomes so. The greater
distance between any two degrees the greater amount of surplus energy.
Now, the mining physicists had