!84 



NATURE 



\_yan. 24, i< 



over ihe sunset becomes vividly brilliant, and at the same time 

 delicately coloured. Over a somewhat depressed circular area, 

 about 12° high and 15° broad, it assumes a pale green tint. 

 Above this comes an equally dazzling pale yellow-orange, and 

 again aljive this a soft rose colour melts away to the zenith. The 

 revival of the light, or return from commencing twilight, is pecu- 

 liarly -triking. Buildings become brillianily illuminated, and 

 strung shadows are cast. All this outglow occurs in no more 

 than live minutes, and now continues for about a quarter of an 

 hour, but the brilliancy gradually contracts in area and sets v\ith 

 a magni ieent display of sunset colours reaching some 120° round 

 the h irizon, until, by fifty minutes after sunset, this light has also 

 gone down to a red line of abiut 2° elevation. I should not 

 have omitted to say that the green light passes to yellow. 



By this time night has fairly well come in the eastern half of 

 the heavens, but already another but more delicate silvery 

 whitenin; begins to show itself on the western curtain, and this 

 also diffuses very rapidly up to the zenith and round to north and 

 south. It also then goes throuf;h a process of contracting, in- 

 tensifying to considerable brightness, and gradually passing 

 through the sunset colours. Night is now full — with or without 

 moonli,'ht, according to date — and from the west, or rather from 

 a point well to the north of it, spreads a delicate but brilliant 

 light, having an almost perfect resemblance to the burning of a 

 vast distant city. The last crimson light of this reflection does 

 not di-appear till an hour and a half after sunset. 



The pheno nena I have attempted to describe cannot possibly, 

 I think, lie explained otherwise than as being the effects of re- 

 flection, and that from a canopy many miles above the earth's 

 surface. The matter of this canopy is highly transparent, 

 for not only are moon and stars brilliantly clear, but in the 

 crescent moon the dark surface of its sphere was on some nights 

 in both months visible and so distinct as to have been noticed 

 independently I ly several persons. (It has been suggested that this 

 greater visiUdity of the dark surface of the moon may be due to 

 a stront»er reflection 'rom the present atmosphere of the earth.) 

 The reflecting matter mu-r, I suppose be water, but in what 

 form an 1 under what conditions it is there so high up day after 

 day in varying weather, it is difiicult to me to conceive. We 

 have had wet days intervening, cloudy days, and very windy 

 days, but on all occasions, e.xcept during rain, the phenomena 

 have Neen visible with strange uniformity. 



Not counting the setting of the silvery glare twenty minutes 

 after sunset, which ought perhaps to be done, there are, it will 

 be seen, two reflected sunsets following the true one. In the 

 morning before -unrise the same phenomena in inverse order 

 are perhips still more remarkable to see. Indeed the whole 

 phen linena, night and morning, have a most unnatural and 

 magical appearance, very different from those of the ordinary 

 sunset and sunrise. 



One oiher phenomenon, also of reflection, has yet to be 

 mentioned. Rarely with much distinctness, but always to be 

 noticed, there appears high up in the east, just after the silvery 

 glare fallowing the sun has set, and lasting only a few minutes, a 

 dim image uf the white glare and the western horizon just after 

 sunset. It is of a delicate rosy light, with a grayish central 

 part. 



I am informed that somewhat similar appearances are being 

 seen in Shan hai. Edward Divers 



Imperial Japanese College of Engineering, Tokio, 

 December 12, 1883 



If ihe red sunsets are to be attributed to smoke and dust in 

 the atin sph.-re from volcanic eruptions, as seems likely from 

 the caniributions in the last number of NATURE at hand 

 (Decern iier 20), then it becomes important to take into account 

 other eruptions which may have happened simultaneously with 

 or shic-that of Krakatoa on August 27, 1883. In any discus- 

 sion -fit ospheric currents as fixing the dates of the appear- 

 ance . f ihese sunset phenomena at difterent places this is of 

 special 1 p .rtance, in order that no confusion may arise in 

 tryiiii; t j reconcile places and dates that may refer to dust and 

 ashf-'^*' 'U ht fro u entirely distinct eruptions. For this reason 

 i seni "u the following extracts. 



Tin- i.r t H fiom the U.S. -ignal Service Monthly VVaUha- 

 Revic:>' lur October, 1883, and is as follows : — 



" Unalaska, Alaska, October 22, 18S3 

 " E.\ wive Officer, Signal Service, U.S.A., Washington, D.C. 

 >' IK,— I forward by this m^iil a sample bottle of sand that 

 fell (hiring the storm of October 20, 1883. 



" At 2.30 p.m. the air became suddenly darkened like night, 

 and soon after a shower of mixed sand and water fell for about 

 ten minutes, covering the ground with a thin layer. The 

 windows were so covered that it was impossible to see through 

 them. 



"This sand is supposed to have come either from the Men- 

 kushin or the new volcano adjacent to Bogoslov. The former is 

 at a distance of about nineteen miles south-west, but for years has 

 only issued forth smoke or steam. The latter is a new one, 

 which made its appearance this summer, and burst out from the 

 bottom of Behring Sea. It has been exceedingly active, as it 

 has already formed an island from 800 to 1200 feet high. 



"According to the report of Capt. Anderson, the discoverer, 

 who sails one of the company's vessels, and who went within 

 2000 yards of it, it presents a most magnificent sight. The fire, 

 smoke, and lava are coming out at many crevices, even under 

 the water line. Large boulders are shot high in the air, which, 

 striking the water, send forth steam and a hissing sound. 



" Bogoslov is about sixty miles from here, in a westerly direc- 

 tion. The new volcano is about one-eighth of a mile north-west 

 of it. "I am, Sir, very respectfully, 



" S. Applegate, 

 " Sergt. Sig. Corps, U.S.A." 



The other extract is from a recent paper as follows : — 



" San Francisco, Cal., December iZ, 1883 



" Prof. Davidson received from Alaska to-day the particulars 

 of the volcanic disturbarces there in October last, near the 

 entrance to Cook's Inlet. On the morning of October 6 a settle 

 ment of fishermen on English Bay Inard a heavy report, and, 

 looking in the direction from whence the sound came, immense 

 volumes of smoke and flame were seen to burst forth from the 

 summit of Mount Augustine. The sky became obscured, and a 

 few hours later great (|uantities of pumice dust began to fall, 

 some of it being fine and smooth, and some gritty. At half-past 

 three o'clock on the same day an earthquake wave thirty feet high 

 came rushing in over the hamlet, sweeping away all the boats 

 and deluging the houses. The tide at the time being low saved 

 the settlement from utter destruction. This wave w as followed 

 by two other wavts eighteen feet high, which were succeeded at 

 irregular intervals by others. The ]3unuce ashes fell to a depth of 

 five inches, making the day so dark that lamps had to be lit. 

 At night the surrounding country was illuminated by flames from 

 the crater. Ordinarily Mount Augu tine is covered with snow, 

 but this year it is completely bare. Upon examination after the 

 disturbai.ces had subsided, it was found that the mountain had 

 been split in two from base to summit, and that the northern 

 slope had fallen to the level of the surrounding cliflfs. Simul- 

 taneously with the eruption, a new island made its appearance in 

 the passage between Chernaboura Island and the mainland. It 

 was seventy- five feet high, and a mile and a half long. So 

 violent was the volcanic action that two extinct volcanoes of the 

 Peninsula of Alaska, lying to the westward of the active volcano 

 Iliamua, 12,000 feet high, burst into activitj', and emitted 

 immense quantities of smoke and dust. Flames were visible at 

 night. It is stated that the wives of a party of Aleut Indians, 

 who were engaged in otter-hunting in that locality, became 

 afraid of the subterranean noises, and refused to stay, returning 

 to their homes. None of those who remained can be found." 



The approximate positions of some of the points mentioned in 

 these reports are as follows : — 



Lat. Long. 



Iliamua 6o-i N. ... I53*-: W. 



Mount Augustine... 59'5 N. ... 153-5 W. 



Unalaska 53-9 N. ... 166-5 W. 



Bogoslov 54'oN. ... i68-o W. 



Here we have the record of (i) a new volcano which appeared 

 near Bogoslov some time during the summer, and had been con- 

 tinuously active and thrown up an i-land 1000 feet high up to 

 some time in October ; (2) an explosive eruption of Mount 

 Aui;ustine on October 6, which split off the whole side of the 

 volcano and distributed ashes to a depth of five inches many 

 miles away, and started a wave in the ocean about thirty feet 

 high ; and (3) of a shower of sand and water on October 20 at 

 Unalaska, which probably arose from some fresh or renewed 

 eruption of a neighbouring volcano. 



Many of these pihenomena resemble those reported from 

 Krakatoa, though on a smaller scale. It is not necessary to 

 point out that a continuous eruption of a new volcano for weeks 



