The eclipse of August 29, 1886, was observed in the West Indies. The English photographs of the corona, taken with a slitless spectroscope, show the hydrogen lines as well as K and f. Tacchini devoted his attention to the spectra of the prominences, and showed that their upper portions contained no hydrogen lines, but only the H and K lines of calcium. He also observed a very extensive "white" prominence. It was shown on the photographs of the corona, but could not be seen in the H[alpha] line with the spectroscope. It has been suggested by Professor G.E. Hale that the colour of a "white" prominence may be due to the fact that the H and K lines (calcium) are of their normal intensity, while the less refrangible prominence lines are, from some unknown cause, comparatively faint. It is known that the intensity of such lines does, in fact, vary, though it is not yet certain that the "white" prominences are produced in this way. The subject is one demanding further observation. High prominences are generally "white" at their summits, "red" at their bases. The Harvard College Observatory photographs show the corona out to 90' from the moon's limb, though no detail is visible beyond 60'. W.H. Pickering made a series of photographic photometric measures of the corona, some of which are given below, together with results deduced by Holden from the eclipses of January and December 1889:-- +--------------------------------------+---------+---------+---------+ | | August | January | December| | | 1886. | 1889. | 1889. | +--------------------------------------+---------+---------+---------+ | Intrinsic actinic brilliancy of the | | | | | brightest parts of the corona | 0.031 | 0.079 | 0.029 | | Do. of the polar rays | · · | 0.053 | 0.016 | | Do. of the sky near the sun | 0.0007 | 0.0050 | 0.0009 | | Ratio of intrinsic brilliancy of the | | | | | brightest parts of the corona to | | | | | that of the sky (actinic) | 44 to 1 | 16 to 1 | 32 to 1 | | Magnitude of the faintest star | | | | | shown on the eclipse negatives | · · | 2.3 | · · | +--------------------------------------+---------+---------+---------+ The results in the first and third columns are derived from plates taken in a very humid climate, and are not very different. The eclipse of August 19, 1887, was total in Japan and Russia, but cloudy weather prevented successful observations except in Siberia and eastern Russia.