[1]It is dated Boston, August 24th, but the year does not appear. She was abroad and he at home in the summers of 1882 and 1887.
[2]Before leaving Korea he spent two delightful weeks at the Footes’.
[3]This came about a month later than ours.
[4](Atlantic Monthly, Nov. 1886, “A Korean Coup d’Etat”).
[5]“The Life and Letters of Lafcadio Hearn by Elizabeth Bisland,” Vol. I, p. 459.
[6]Ib., Vol. II, p. 28.
[7]Ib., Vol. II, p. 30.
[8]Ib., Vol. II, p. 487. See also pp. 479, 505. Percival’s “Occult Japan” a study of Shinto trances, published in 1894, he did not like at all. It struck him only “as a mood of the man, an ugly supercilious one, verging on the wickedness of a wish to hurt—there was in ‘The Soul of the Far East’ an exquisite approach to playful tenderness—utterly banished from ‘Occult Japan.’” Id., pp. 204, 208. By this time Hearn seems to have come to resent criticism of the Japanese.
[9]The exact elevation proved to be 12,611.
[10]These discoveries have since been doubted.
[11]The theory of the gradual loss of water is very doubtful, but Percival’s main conclusions depend on the present aridity of the planet, not on its assumed history.
[12]In a lecture shortly before his death he said: “Where Schiaparelli discovered 140, between 700 and 800 have been detected at Flagstaff.”
[13]Thereafter the equipment of the Observatory was steadily enlarged—notably by a 42-inch reflector in 1909—until now there are five domes, and much auxiliary apparatus.
[14]Vol. 19, No. 218.
[15]Percival’s statement of this may be found also in “Mars as the Abode of Life,” Chapter III.
[16]Their existence was proved, although the grain of the best plates is too coarse to distinguish between sharp lines and diffuse bands.
[17]While written in the third person the words are clearly his own.
[18]His determination of the Martian temperature has since been very closely verified.
[19]In a letter to Dr. V. M. Slipher on Oct. 4, 1902 he writes:
“There has come into my head a new way for detecting the spectral lines due to a planet’s own atmospheric absorption, and I beg you will apply it to Mars so soon as the Moon shall be in position to make a comparison spectrum.
“It is this. At quadrature of an exterior planet we are travelling toward that planet at the rate of 18.5 miles a second and we are carrying of course our own atmosphere with us. Our motion shortens all the wave-lengths sent us from the planet, including those which have suffered absorption in its atmosphere. When the waves reach our atmosphere those with a suitable wavelength are absorbed by it and these wave-lengths are unaffected by our motion since it is at rest as regards us. Even were the two atmospheres alike the absorbed wave-lengths reaching us would thus be different since the one set, the planet’s, have been shifted by our motion toward it while the other set, our own, are such as they would be at rest. We thus have a criterion for differentiating the two. And the difference should be perceptible in your photographs. For the shift of Jupiter’s lines due to rotation is such as 8. × 2. = 16 miles a second produces, which is less than 18.5 and about what you will get now.”
[20]So far as the shooting stars are concerned this opinion was based upon their velocities, which have since been found in many cases to be greater than was then supposed.
[21]Opic has recently shown that the sun’s effective domain is even larger.
[22]Later observations seem to show that Mercury’s periods of rotation and revolution are not the same, but nearly so.
[23]It now appears very improbable that these are real comet families.
[24]Recent results indicate that these are much smaller, and sometimes move faster, than was formerly believed.
[25]This theory, though generally held till 1930, has apparently been disproved by Jeffries.
[26]The periods of revolution and rotation have since appeared not to be exactly the same.
[27]Radiometric measures of late years show the outer surface of Jupiter to be at a very low temperature.
[28]As these thickenings, which he called tores, were not perceived the next time the rings were seen edgewise—although probably there—it is needless to dwell more upon them.
[29]By continued, and quite recent, study at Flagstaff the content of this gas has been found to be for Jupiter and Saturn one half, for Uranus five times and for Neptune twenty-five times the amount of th
