At the Southampton meeting of the British Association, Captain Abney read a paper in which he called attention to the fact that photographs taken at high altitudes show skies that are nearly black by comparison with bright objects projected against them, and he went on to show that the higher above the sea level the observer went, the darker the sky really is and the fainter the spectrum. In fact, the latter shows but little more than a band in the violet and ultraviolet at a height of 8,500 feet, while at sea-level it shows nearly the whole photographic spectrum. The only reason of this must be particles of some reflecting matter from which sunlight is reflected. The author refers this to watery stuff, of which nine-tenths is left behind at the altitude at which be worked. He then showed that the brightness of the ultra-violet of direct sunlight increased enormously the higher the observer went, but only to a certain point, for the spectrum suddenly terminated about 2,940 wave-length. This abrupt absorption was due to extra-atmospheric causes and perhaps to space. The increase in brightness of the ultra-violet was such that the usually invisible rays, L, M, N, could be distinctly seen, showing that the visibility of these rays depended on the intensity of the radiation. The red and ultra-red part of the spectrum was also considered. He showed that the absorption lines were present in undiminished force and number at this high altitude, thus placing their origin to extra-atmospheric causes. The absorption from atmospheric causes of radiant enemy in these parts he showed was due to "water-stuff," which he hesitated to call aqueous vapor, since the banded spectrum of water was present, and not lines. The B and A line he also stated could not be claimed as telluric lines, much less as due to aqueous vapor, but must originate between the sun and our atmosphere. The author finally confirmed the presence of benzine and ethyl in the same region. He had found their presence indicated in the spectrum at sea-level, and found their absorption lines with undiminished intensity at 8,500 feet. Thus, without much doubt, hydrocarbons must exist between our atmosphere and the sun, and, it may be, in space. Prof. Langley, following Capt. Abney, observed: The very remarkable paper just read by Captain Abney has already brought information upon some points which the one I am about, by the courtesy of the Association, to present, leaves in doubt. It will be understood then that the references here are to his published memoirs only, and not to what we have just heard.