"It is very clear to me that the insensibility which came upon Glaisher, and in a lesser degree upon Coxwell, when, in 1862, they ascended in a balloon to the height of thirty thousand feet, was due to the extreme speed with which a perpendicular ascent is made. Doing it at an easy gradient and accustoming oneself to the lessened barometric pressure by slow degrees, there are no such dreadful symptoms. At the same great height I found that even without my oxygen inhaler I could breathe without undue distress. It was bitterly cold, however, and my thermometer was at zero Fahrenheit. At one-thirty I was nearly seven miles above the surface of the earth, and still ascending steadily. I found, however, that the rarefied air was giving markedly less support to my planes, and that my angle of ascent had to be considerably lowered in consequence. It was already clear that even with my light weight and strong engine-power there was a point in front of me where I should be held. To make matters worse, one of my sparking-plugs was in trouble again and there was intermittent missfiring in the engine. My heart was heavy with the fear of failure. "It was about that time that I had a most extraordinary experience. Something whizzed past me in a trail of smoke and exploded with a loud, hissing sound, sending forth a cloud of steam. For the instant I could not imagine what had happened. Then I remembered that the earth is for ever being bombarded by meteor stones, and would be hardly inhabitable were they not in nearly every case turned to vapour in the outer layers of the atmosphere. Here is a new danger for the high-altitude man, for two others passed me when I was nearing the forty-thousand-foot mark. I cannot doubt that at the edge of the earth's envelope the risk would be a very real one. "My barograph needle marked forty-one thousand three hundred when I became aware that I could go no farther. Physically, the strain was not as yet greater than I could bear, but my machine had reached its limit. The attenuated air gave no firm support to the wings, and the least tilt developed into side-slip, while she seemed sluggish on her controls. Possibly, had the engine been at its best, another thousand feet might have been within our capacity, but it was still missfiring, and two out of the ten cylinders appeared to be out of action. If I had not already reached the zone for which I was searching then I should never see it upon this journey. But was it not possible that I had attained it? Soaring in circles like a monstrous hawk upon the forty-thousand-foot level I let the monoplane guide herself, and with my Mannheim glass I made a careful observation of my surroundings. The heavens were perfectly clear; there was no indication of those dangers which I had imagined.