Having adopted this view of the subject, I had little farther hesitation. Granting that on my passage I should meet with atmosphere _essentially_ the same as at the surface of the earth, I conceived that, by means of the very ingenious apparatus of M. Grimm, I should readily be enabled to condense it in sufficient quantities for the purpose of respiration. This would remove the chief obstacle in a journey to the moon. I had indeed spent some money and great labor in adapting the apparatus to the purposes intended, and I confidently looked forward to its successful application, if I could manage to complete the voyage within any reasonable period. This brings me back to the _rate_ at which it might be possible to travel.
It is true that balloons, in the first stage of their ascensions from the earth, are known to rise with a velocity comparatively moderate. Now the power of elevation lies altogether in the superior lightness of the gas in the balloon, compared with the atmospheric air; and, at first sight, it does not appear probable that, as the balloon acquires altitude, and consequently arrives successively in atmospheric strata of densities rapidly diminishing--I say it does not appear at all reasonable that, in this its progress upwards, the original velocity should be accelerated. On the other hand, I was not aware that, in any recorded ascension, a diminution was apparent in the absolute rate of ascent--although such should have been the case, if on account of nothing else, on account of the escape of gas through balloons ill-constructed, and varnished with no better material than the ordinary varnish. It seemed, therefore, that the effect of such an escape was only sufficient to counterbalance the effect of some accelerating power. I now considered, that provided in my passage I found the medium I had imagined, and provided it should prove to be actually and _essentially_ what we denominate atmospheric air, it could make comparatively little difference at what extreme state of rarefaction I should discover it--that is to say, in regard to my power of ascending--for the gas in the balloon would not only be itself subject to a rarefaction partially similar, but, _being what it was_, would still, at all events, continue specifically lighter than any compound whatever of mere nitrogen and oxygen. In the meantime the force of gravitation would be constantly diminishing, in proportion to the squares of the distances, and thus, with a velocity prodigiously accelerating, I should at length arrive in those distant regions where the power of the earth's attractions would be superseded by the moon's. In accordance with these ideas, I did not think it worth while to encumber myself with more provisions than would be sufficient for a period of forty days.