In this
      bag, which was of sufficient dimensions, the entire car was in a
      manner placed. That is to say, it (the bag) was drawn over the
      whole bottom of the car, up its sides, and so on, along the
      outside of the ropes, to the upper rim or hoop where the net-work
      is attached. Having pulled the bag up in this way, and formed a
      complete enclosure on all sides, and at bottom, it was now
      necessary to fasten up its top or mouth, by passing its material
      over the hoop of the net-work—in other words, between the
      net-work and the hoop. But if the net-work were separated from
      the hoop to admit this passage, what was to sustain the car in
      the meantime? Now the net-work was not permanently fastened to
      the hoop, but attached by a series of running loops or nooses. I
      therefore undid only a few of these loops at one time, leaving
      the car suspended by the remainder. Having thus inserted a
      portion of the cloth forming the upper part of the bag, I
      refastened the loops—not to the hoop, for that would have been
      impossible, since the cloth now intervened—but to a series of
      large buttons, affixed to the cloth itself, about three feet
      below the mouth of the bag, the intervals between the buttons
      having been made to correspond to the intervals between the
      loops. This done, a few more of the loops were unfastened from
      the rim, a farther portion of the cloth introduced, and the
      disengaged loops then connected with their proper buttons. In
      this way it was possible to insert the whole upper part of the
      bag between the net-work and the hoop. It is evident that the
      hoop would now drop down within the car, while the whole weight
      of the car itself, with all its contents, would be held up merely
      by the strength of the buttons. This, at first sight, would seem
      an inadequate dependence; but it was by no means so, for the
      buttons were not only very strong in themselves, but so close
      together that a very slight portion of the whole weight was
      supported by any one of them. Indeed, had the car and contents
      been three times heavier than they were, I should not have been
      at all uneasy. I now raised up the hoop again within the covering
      of gum-elastic, and propped it at nearly its former height by
      means of three light poles prepared for the occasion. This was
      done, of course, to keep the bag distended at the top, and to
      preserve the lower part of the net-work in its proper situation. All that now remained was to fasten up the mouth of the
      enclosure; and this was readily accomplished by gathering the
      folds of the material together, and twisting them up very tightly
      on the inside by means of a kind of stationary tourniquet. “In the sides of the covering thus adjusted round the car, had
      been inserted three circular panes of thick but clear glass,
      through which I could see without difficulty around me in every
      horizontal direction. In that portion of the cloth forming the
      bottom, was likewise, a fourth window, of the same kind, and
      corresponding with a small aperture in the floor of the car
      itself. This enabled me to see perpendicularly down, but having
      found it impossible to place any similar contrivance overhead, on
      account of the peculiar manner of closing up the opening there,
      and the consequent wrinkles in the cloth, I could expect to see
      no objects situated directly in my zenith. This, of course, was a
      matter of little consequence; for had I even been able to place a
      window at top, the balloon itself would have prevented my making
      any use of it. “About a foot below one of the side windows was a circular
      opening, eight inches in diameter, and fitted with a brass rim
      adapted in its inner edge to the windings of a screw. In this rim
      was screwed the large tube of the condenser, the body of the
      machine being, of course, within the chamber of gum-elastic. Through this tube a quantity of the rare atmosphere circumjacent
      being drawn by means of a vacuum created in the body of the
      machine, was thence discharged, in a state of condensation, to
      mingle with the thin air already in the chamber. This operation
      being repeated several times, at length filled the chamber with
      atmosphere proper for all the purposes of respiration. But in so
      confined a space it would, in a short time, necessarily become
      foul, and unfit for use from frequent contact with the lungs. It
      was then ejected by a small valve at the bottom of the car—the
      dense air readily sinking into the thinner atmosphere below. To
      avoid the inconvenience of making a total vacuum at any moment
      within the chamber, this purification was never accomplished all
      at once, but in a gradual manner—the valve being opened only for
      a few seconds, then closed again, until one or two strokes from
      the pump of the condenser had supplied the place of the
      atmosphere ejected. For the sake of experiment I had put the cat
      and kittens in a small basket, and suspended it outside the car
      to a button at the bottom, close by the valve, through which I
      could feed them at any moment when necessary. I did this at some
      little risk, and before closing the mouth of the chamber, by
      reaching under the car with one of the poles before mentioned to
      which a hook had been attached. “By the time I had fully completed these arrangements and filled
      the chamber as explained, it wanted only ten minutes of nine
      o’clock. During the whole period of my being thus employed, I
      endured the most terrible distress from difficulty of
      respiration, and bitterly did I repent the negligence or rather
      fool-hardiness, of which I had been guilty, of putting off to the
      last moment a matter of so much importance. But having at length
      accomplished it, I soon began to reap the benefit of my
      invention. Once again I breathed with perfect freedom and
      ease—and indeed why should I not? I was also agreeably surprised
      to find myself, in a great measure, relieved from the violent
      pains which had hitherto tormented me. A slight headache,
      accompanied with a sensation of fulness or distention about the
      wrists, the ankles, and the throat, was nearly all of which I had
      now to complain. Thus it seemed evident that a greater part of
      the uneasiness attending the removal of atmospheric pressure had
      actually worn off, as I had expected, and that much of the pain
      endured for the last two hours should have been attributed
      altogether to the effects of a deficient respiration.