380 



. KNOWLEDGE • 



(Dec. 21, 1883. 



11 a.m. on the 26th she enters the narrow strip which forms the 

 northern part of Scorpio, and having crossed this, at 11 p.m. enters 

 on to her path througli the southern part of Ophiuchus and Serpens. 

 By 6 p.m. on the 28th she quits Serpens for Sagittarius, whence she 

 passes, at 5 a.m. on the 31st., into Capricomus. At midnight on 

 the last night of the year she enters Aquarius. She does not leare 

 Aquarius until about 7 p.m. on January 3rd, when she trarels into 

 Pisces. We there leave her. 



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A BLUE IIOOX. 



[1056] — On December 4, at 4.30, p.m., I was summoned by an 

 observant assistant (Mr. T. H. Dean) to see a " blue moon ! " Sure 

 enough, the moon's crescent was of a steely, greenish-blue — 

 " electric blue," I believe the precise tint is called. The setting 

 sun was marked by coppei-y-red stratus clouds ; elsewhere cumulus 

 prevailed, with patches of blue sky. The phenomenon only lasted 

 for some ten or fifteen minutes. I should attribute it to matter 

 (capable of absorbing the red rays) suspended in the upper regions 

 of the atmosphere. The sun's rays having to pass twice through 

 these upper layers of air, were reduced at last to the blue end of 

 the spectrum only. That most of this finely-divided, suspended 

 matter may have been derived from the fearful volcanic eruptions 

 which occurred some time back in the East Indian Archipelago, I 

 have no reason to doubt. At least, I have not yet heard of any 

 more feasible theory. W. Jerome Harrison. 



36, Lodge-road. 



[The theory that the blue and green sun and moon and recent 

 strange sunsets have been due to the volcanic eruptions near the 

 Sunda Straits, requires, — (1), that much more should have been 

 expelled than was apparentK* expelled (to spread so widely) ; (2), 

 that to reach Trinidad, Panama, and Yokohama the expelled matter 

 should have travelled from sixty-five to seventy-five miles per hour, 

 but have gone in quite leisurely fashion to Ceylon and South India. 

 I fancy we all thought Krakatoa had something to do with the 

 matter when we had the news from Ceylon. But now I think 

 every one who has studied the evidence in full and is competent 

 to form an opinion perceives that the theory has become altogether 

 untenable. Professor Piazzi Smyth, I see. holds as Mr. Ranyard 

 does, that meteoric dust explains all the phenomena. — R. P.] 



STRANGE SUNSETS .iND BLUE MOON. 



[1057] — Pardon me intruding on your time, and perhaps on your 

 space, but might I suggest a use of aeronautics to solve, perhaps, 

 to some extent, the at present insoluble recent solar and lunar 

 phenomena ? We know how Gay-Lussac and Biot in 1802, and 

 afterwards Gay-Lussac himself, at a height of 22,000 ft. above 

 Paris, or four miles and a quarter above the level of the sea, 

 intrepidly experimented on magnetism, hygrometry, &c. Whatever 

 the dust pervading the space contiguous to our earth may be, surely 

 at such a height some of it might be collected and examined in the 

 same way as atmospheric dust has been collected and examined, as 

 described in a past article in Knowledge. Is there no one of those 

 who make aeronautic voyages as a pleasure who will place tlieir 

 experience and apparatus at the disposal of scientific men — that is 

 to say, if they think such a course likely to meet with ajiy success ? 



Unluckily Mr. Eaynard's article appeared just after the first fall 



of snow, with his suggestion to analyse it, in order to ascertain 

 whether a greater quantity of dust were present than usual. 1 

 trust that he has done so, and will give us his results. 



In that unsatisfying article in the Dailij .Vcus of the 8th inst. the 

 writer has attempted to explain the green moon by the pinkish 

 colour of the sky beyond it. A friend of mine, however, at Red 

 Hill, states that he saw the crescent moon green on Wednesday, 

 5th inst., at 5.10 p.m. on the ordinary starry background, and not on 

 a pink background. He says that as it sank in the west it assumed 

 the reddish colour. Edward A. Martin. 



STRANGE SUNSET. 

 [1058] — At Montrose, as at other places, ".he remarkable "after- 

 glow" has been observed, and the following observations of it at 

 Montrose may prove interesting to Mr. A. 0. Banyard and your 

 readers. 



1. I observed it first here on the evening of Sanday, Nov. 25, 

 when the sky was filled with a deep red colour, looking very like (as 

 I at first supposed it to be) a very bright Aurora. The glow con- 

 tinued in the sky at every sunset, with more or less intensity, for 

 the whole week, and on Nov. 30 it attained its maximum (so to 

 speak), for, just as the sun set, the whole sky was filled with 

 colours of the most brilliant hues ; on the horizon was a band of 

 bright yellow streaked across its centre trarsversely by another of 

 green, while overhead the sky was of an orange colour, gradually 

 merging into brilliant red. That same morning a " preglow " of 

 as great intensity as the afterglow was observed. For the nest 

 three days, Dec. 1, 2, 3, it was foggy and dull, and on the evening 

 of the 3rd and morning of ith there was a heavy fall of snow. 

 For the rest of that week there was clear, hard weather, with 

 occasional snowfalls, and the afterglow disappeared entirely, the 

 sun rising and sinking quite clearly. 



2. On the morning of Sunday, Dec. 9, the weather changed, the 

 snow melted and rain fell. In the evening the afterglow was 

 visible again, commencing about fifteen minutes after the sun had 

 set, and continuing for nearly an hour. This time I observed that 

 the colour of the sky overhead was not red, b.it of a brown orange 

 tint, and it also seemed to be more scattered. This morning (10th) 

 there was a beautiful "preglow," which was observed about an 

 hour before sunrise, the colours being the very same as those of the 

 evening before. 



3. I have observed that a very black bank of cloud usually 

 stretches along the horizon, from west to east, whenever a glow 

 is visible. The upper edge of this cloud is very remarkable, being 

 extremely straight, and pointed towards the west. 



Now, 1 would like to ask a few questions. Could the rays of the 

 young moon (which was high in the sky at sunset last week) have 

 affected the glow and rendered it iuWsible ? Could the rain or the 

 snow have brought the dust nearer the earth, and so account for 

 the orange colour visible overhead last evening, the orange rays 

 being shorter than the red ? or could the phenomenon be attributed 

 to ice-particles floating in the higher regions of our atmosphere ? 



James B. Findlav. 



SUN-SPOTS AND COMET. 



[1059] — It may interest some of your readers, who have not 

 good telescopes, to know that a large number of spots can be seen 

 with only a small instrument. I use a telescope only 1 ft. long, 

 with an object-glass 1 in. in diameter; on forty days on which I 

 have been able to observe — from Oct. 21 to Dec. 11 — I have seen 

 about 150 different spots ; on three days. Dec. 4, 5, and 6, no spots 

 were visible. On Nov. 14, 18 were visible ; to-day (Dec. 11) 12 ai-e 

 visible, of which three can be seen by the naked eye. 



The comet has been visible to the naked eye for abont a fortnight. 

 Ni'RTBcoTE W. Thomas. 



COINCIDENCE.S. 



[lOGO] — I think the following adventures of a bank-note efjual 

 the wanderings of your con'espondence as recorded in KNOWLErGt 

 of the 16th inst. A subordinate in a Government office stationed 

 on an island off the coast of Ireland was entrusted with a bank- 

 note for which he was to get cash at a bank on the mainland. He 

 crossed the water, paid some Wsits to other offices where he had 

 letters to deliver, and arrived at the bank only to find that the note 

 was gone. Inquirj- was made at the offices where he had called, 

 but no trace of the note could be found, and Timothy (for so I will 

 call him) returned almost in tears to the island. Every effort was 

 made to discover the missing note — for no one doubted the 

 honesty of the subordinate. The priest even mentioned the 

 circumstance at the services, which amongst a Caiholic community 

 sometimes has a result. To make a long story short, the note re- 

 mained undiscovered for six montlis. when ouo day it was received 



