a whole
year--Barbican having taken care to be on the safe side, in case the
Projectile might land in a deserted region of the Moon. As for the water
and the other liquors, the travellers had enough only for two months.
Relying on the latest observations of astronomers, they had convinced
themselves that the Moon's atmosphere, being heavy, dense and thick in
the deep valleys, springs and streams of water could hardly fail to show
themselves there. During the journey, therefore, and for the first year
of their installation on the Lunar continent, the daring travellers
would be pretty safe from all danger of hunger or thirst.

The air supply proved also to be quite satisfactory. The _Reiset_ and
_Regnault_ apparatus for producing oxygen contained a supply of chlorate
of potash sufficient for two months. As the productive material had to
be maintained at a temperature of between 7 and 8 hundred degrees Fahr.,
a steady consumption of gas was required; but here too the supply far
exceeded the demand. The whole arrangement worked charmingly, requiring
only an odd glance now and then. The high temperature changing the
chlorate into a chloride, the oxygen was disengaged gradually but
abundantly, every eighteen pounds of chlorate of potash, furnishing the
seven pounds of oxygen necessary for the daily consumption of the
inmates of the Projectile.

Still--as the reader need hardly be reminded--it was not sufficient to
renew the exhausted oxygen; the complete purification of the air
required the absorption of the carbonic acid, exhaled from the lungs.
For nearly 12 hours the atmosphere had been gradually becoming more and
more charged with this deleterious gas, produced from the combustion of
the blood by the inspired oxygen. The Captain soon saw this, by noticing
with what difficulty Diana was panting. She even appeared to be
smothering, for the carbonic acid--as in the famous _Grotto del Cane_ on
the banks of Lake Agnano, near Naples--was collecting like water on the
floor of the Projectile, on account of its great specific gravity. It
already threatened the poor dog's life, though not yet endangering that
of her masters. The Captain, seeing this state of things, hastily laid
on the floor one or two cups containing caustic potash and water, and
stirred the mixture gently: this substance, having a powerful affinity
for carbonic acid, greedily absorbed it, and after a few moments the air
was completely purified.

The others had