earth subtended an angular breadth of twenty-five degrees. On the fourteenth, this had greatly diminished; on the fifteenth, a still more rapid decrease was observable; and, on retiring for the night of the sixteenth, I had noticed an angle of no more than about seven degrees and fifteen minutes. What, therefore, must have been my amazement, on awakening from a brief and disturbed slumber, on the morning of this day, the seventeenth, at finding the surface beneath me so suddenly and wonderfully augmented in volume, as to subtend no less than thirty-nine degrees in apparent angular diameter! I was thunderstruck! No words can give any adequate idea of the extreme, the absolute horror and astonishment, with which I was seized, possessed, and altogether overwhelmed. My knees tottered beneath me—my teeth chattered—my hair started up on end. “The balloon, then, had actually burst!” These were the first tumultuous ideas which hurried through my mind: “The balloon had positively burst!—I was falling—falling with the most impetuous, the most unparalleled velocity! To judge from the immense distance already so quickly passed over, it could not be more than ten minutes, at the farthest, before I should meet the surface of the earth, and be hurled into annihilation!” But at length reflection came to my relief. I paused; I considered; and I began to doubt. The matter was impossible. I could not in any reason have so rapidly come down. Besides, although I was evidently approaching the surface below me, it was with a speed by no means commensurate with the velocity I had at first conceived. This consideration served to calm the perturbation of my mind, and I finally succeeded in regarding the phenomenon in its proper point of view. In fact, amazement must have fairly deprived me of my senses, when I could not see the vast difference, in appearance, between the surface below me, and the surface of my mother earth. The latter was indeed over my head, and completely hidden by the balloon, while the moon—the moon itself in all its glory—lay beneath me, and at my feet.
The stupor and surprise produced in my mind by this extraordinary ·422· change in the posture of affairs, was perhaps, after all, that part of the adventure least susceptible of explanation. For the bouleversement in itself was not only natural and inevitable, but had been long actually anticipated, as a circumstance to be expected whenever I should arrive at that exact point of my voyage where the attraction of the planet should be superseded by the attraction of the satellite—or, more precisely, where the gravitation of the balloon towards the earth should be less powerful than its gravitation towards the moon. To be sure I arose from a sound slumber, with all my senses in confusion, to the contemplation of a very startling phenomenon, and one which, although expected, was not expected at the moment. The revolution itself must, of course, have taken place in an easy and gradual manner, and it is by no means clear that, had I even been awake at the time of the occurrence, I should have been made aware of it by any internal evidence of an inversion—that is to say, by any inconvenience or disarrangement, either about my person or about my apparatus.
It is almost needless to say, that, upon coming to a due sense of my situation, and emerging from the terror which had absorbed every faculty of my soul, my attention was, in the first place, wholly directed to the contemplation of the general physical appearance of the moon. It lay beneath me like a chart—and although I judged it to be still at no inconsiderable distance, the indentures of its surface were defined to my vision with a most striking and altogether unaccountable distinctness. The entire absence of ocean or sea, and indeed of any lake or river, or body of water whatsoever, struck me, at the first glance, as the most extraordinary feature in its geological condition. Yet, strange to say, I beheld vast level regions of a character decidedly alluvial, although by far the greater portion of the hemisphere in sight was covered with innumerable volcanic mountains, conical in shape, and having more the appearance of artificial than of natural protuberances. The highest among them does not exceed three and three-quarter miles in perpendicular elevation; but a map of the volcanic districts of the Campi Phlegræi would afford to your Excellencies a better idea of their general surface than any unworthy description I might think proper to attempt. The greater part of them were in a state of evident eruption, and gave me fearfully to understand their fury and their power, by the repeated thunders of the mis-called meteoric stones, which now rushed upwards by the balloon with a frequency more and more appalling.
April 18th. To-day I found an enormous increase in the moon’s ·423· apparent bulk—and the evidently accelerated velocity of my descent, began to fill me with alarm. It will be remembered, that, in the earliest stage of my speculations upon the possibility of a passage to the moon, the existence, in its vicinity, of an atmosphere dense in proportion to the bulk of the planet, had entered largely into my calculations; this too in spite of many theories to the contrary, and, it may [be] added, in spite of a general disbelief in the existence of any lunar atmosphere at all. But, in addition to what I have already urged in regard to Encke’s comet and the zodiacal light, I had been strengthened in my opinion by certain observations of Mr. Schroeter, of Lilienthal. He observed the moon, when two days and a half old, in the evening soon after sunset, before the dark part was visible, and continued to watch it until it became visible. The two cusps appeared tapering in a very sharp faint prolongation, each exhibiting its farthest extremity faintly illuminated by the solar rays, before any part of the dark hemisphere was visible. Soon afterwards, the whole dark limb became illuminated. This prolongation of the cusps beyond the semicircle, I thought, must have arisen from the refraction of the sun’s rays by the moon’s atmosphere. I computed, also, the height of the atmosphere (which could refract light enough into its dark hemisphere, to produce a twilight more luminous than the light reflected from the earth when the moon is about 32° from the new,) to be 1356 Paris feet; in this view, I supposed the greatest height capable of refracting the solar ray, to be 5376 feet. My ideas upon this topic had also received confirmation by a passage in the eighty-second volume of the Philosophical Transactions, in which it is stated, that, at an occultation of Jupiter’s satellites, the third disappeared after having been about 1″ or 2″ of time indistinct, and the fourth became indiscernible near the limb. (†3)
Upon the resistance, or more properly, upon the support of an ·424· atmosphere, existing in the state of density imagined, I had, of course, entirely depended for the safety of my ultimate descent. Should I then, after all, prove to have been mistaken, I had in consequence nothing better to expect, as a finale to my adventure, than being dashed into atoms against the rugged surface of the satellite. And, indeed, I had now every reason to be terrified. My distance from the moon was comparatively trifling, while the labor required by the condenser was diminished not at all, and I could discover no indication whatever of a decreasing rarity in the air.
April 19th. This morning, to my great joy, about nine o’clock, the surface of the moon being frightfully near, and my apprehensions excited to the utmost, the pump of my condenser at length gave evident tokens of an alteration in the atmosphere. By ten, I had reason to believe its density considerably increased. By eleven, very little labor was necessary at the apparatus; and at twelve o’clock, with some hesitation, I ventured to unscrew the tourniquet, when, finding no inconvenience from having done so, I finally threw open the gum-elastic chamber, and unrigged it from around the car. As might have been expected, spasms and violent headache were the immediate consequences of an experiment so precipitate and full of danger. But these and other difficulties attending respiration, as they were by no means so great as to put me in peril of my life, I determined to endure as I best could, in consideration of my leaving them behind me momently in my approach to the denser strata near the moon. This approach, however, was still impetuous in the extreme; and it soon became alarmingly certain that, although I had probably not been deceived in the expectation of an atmosphere dense in proportion to the mass of the satellite, still I had been wrong in supposing this density, even at the surface, at all adequate to the support of the great weight contained in the car of my balloon. Yet this should have been the case, and in an equal degree as at the surface of the earth, the actual gravity of bodies at either planet supposed in the ratio of the atmospheric condensation. That it was not the case, however, my precipitous downfall gave testimony enough; why it was not so, can only be explained by a reference to those possible geological disturbances to which I have formerly alluded. At all events I was now close upon the planet, and coming down with the most terrible impetuosity. I lost not a moment, accordingly, in throwing overboard first my ballast, then my water-kegs, then my condensing apparatus and gum-elastic chamber, and finally every article within