I still had far to travel, so I increased the current from the tenth to the fifteenth intensity. Again I was conscious of that feeling of lightness in my head, and the humming and vibration of everything increased. I had almost forgotten my personal sensations; had quite forgotten them, in fact, for several hours past. I passed fifteen thousand years. I could see that the ocean to the north had come further inland. There was now, from my altitude, no evidence of mankind visible, nor anything to indicate that man had ever lived on this earth. The scene was more blurred now and grayer. I could still make out the bay to the south, with a range of hills on Staten Island and water behind it and to the west as far as I could see. The rivers bounding Manhattan were still there, but the Palisades along the Hudson had broken down. Directly beneath me was forest. I believed I had not drifted much from my original position. I was still over where Central Park had been some twenty thousand years before. The forest--it was more like woods--covered a narrow rolling country between the two rivers. I knew I was moving through time much more swiftly now, perhaps twice as fast as before. The vegetation was blurred, almost distorted. It was changing constantly and, on the whole, was growing sparser, more stunted. It was as though I were traveling northward, or ascending a mountain almost to the timber line. Another interval passed. My time-velocity had so increased that once I thought I could see a hill rising. But that probably was imagination. I had been gone some twelve hours--it was almost ten o'clock--when I realized I was about exhausted. My head was reeling; my eyes burned and watered. It was growing much colder--so cold that I switched on the electrical heating apparatus. That was when the dials recorded between twenty and thirty thousand years. I don't remember exactly. I was confused. The scene beneath me was noticeably whiter, and I was now drifting to the south. I felt perturbed. I was going too far. I had reached about forty-five thousand years when abruptly I realized that there was no vegetation in the scene! Just when it melted away I had not noticed. It was all a whitish blur, now, that suggested very snowy winters blended with a shorter summer season. I leaped to the control, and threw its handle back, pausing an instant at each intensity of current until I had come to the first. There I left it. These new sensations of decreasing my time-velocity so abruptly were almost equally as severe as those when I started. The humming slowed up. My whole body seemed to be turning to lead--or freezing. I was heavy, stiff, and cold. I was standing up, and I managed to grip the side of the cabin for support, and reaching down, I threw off the switch, cutting off the current completely. There came a tremendous, soundless clap in my head; I seemed tumbling headlong into an abyss of blackness.