April lo, 1884] 



NATURE 



54 9 



crimson glow. These skies were often still more gorgeous in the 

 morning, and on some occasions were so wonderful as to be 

 styled Jrightful by some observers. I witnessed one of these 

 sunrises from an altitude of 3cxra feet in January, and it was 

 almost an awful sight. The view to the east was over about 

 thirty miles of plains to distant mountains ; a low mist hung over 

 the low ground, and the surface appeared slightly rolling as seen 

 from above. The sky half an hour before sunrise was so 

 intensely red, almost to the zenith, that it gave this mist the 

 appearance of a sea of blood. Every object, tree-trunks, fern- 

 trees, bushes, rocks, and the cottages about the hills, was of a 

 similar lurid colour ; still there was not yet sufficient light to 

 read by comfortably. This display reminded me of the wonder- 

 fully red aurora witnessed in Australia on April 5, 1870, when 

 the red light was so intense that ordinary newspaper type could 

 be read by it at ten o'clock on a moonless night, the type 

 appearing as if set in a blood-red sheet. This was the first time 

 I recorded the red spectrum line of the aurora, and I think was 

 one of the earliest observations of this fact. 



Some of the recent sunsets have looked very much like an 

 aurora in the west, and faint traces of stratification lent addi- 

 tional similarity ; indeed on one night early in December, the 

 nflei-glow merged into a beautiful aurora, and silver streamers 

 were seen before all the red glow had disappeared. 



From all over Australia reports of wonderful sunsets and sun- 

 rises have been sent to me. In one case the red gltnu was re- 

 ported as margined by an immense black bow stretching across 

 from north-west to south-west. On several occasions these 

 glows prolonged the twilight considerably, and a correspondent 

 at Urana, in New South Wales, described one occasion where 

 approaching darkness after one of these sunsets at length com- 

 pelled him to leave oft" watering his garden, but suddenly the 

 light increased again sufficiently to induce him to resume liis 

 work ; and he states that a similar accession of light — each time 

 fainter — occurred on that same evening. 



The season over the south of Australia especially, but all over 

 the continent, has been remarkable, and, so far as this colony is 

 concerned, unprecedented in my thirty-three years' knowledge of 

 the climate. January, February, and March are usually our dry, 

 hot months ; this year they have been wet and cold ones. The 

 average rainfall for January has been I '60 inches ; this year it 

 was 4*75 inches. For February the average is i'95 inches, and 

 up to this date (the 27th) it has been also I '95 inches. The 

 mean temperature for January was 3° "5 below the average, and 

 for February 2° below. .Stormy, squally, wintry weather has 

 predominated, with now and then a very hot or a tropical day 

 for a change. 



Even before the Krakatoa outburst the northern parts of Tas- 

 mania had become subject to prolonged earih tremors, with now 

 and then a decided earthquake shock. These disturbances still 

 continue, and appear to be extending northwards, for on the 

 15th of this month a shock was felt at Gabo Island, at the south- 

 east extremity of Australia, and a very severe one again on the 

 17th, when a curious and sudden barometric disturbance, not 

 unlike that at the time of the Java catastrophe, was shown on 

 our barographs. 



While on this subject it may be as well to state that Mr. 

 Barrachi, one of my assistants, while at Port Darwin determining 

 the difference of longitude between that place and Singapore in 

 March 1883, saw sunsets, followed by after-glows, which pro- 

 longed the usual short twilights to a very considerable extent, 

 and he states they were equally remarkable with those witnessed 

 here. They only occurred either just before or just after very 

 heavy rains. 



Referring to the various hypotheses wliich have found their 

 way into print explanatory of the unusual phenomena attending 

 sunrise and sunset since Augtist 1883, the belief that they have 

 been in some way brought about by the Krakatoa eruption 

 appears to be generally accepted, and while some doubt may be 

 thrown on this assumption by records of equally remarkable 

 chromatic effects at both sunrise and sunset and about the sun 

 at other times of the day prior to the eruption, it must be ad- 

 mitted at present that the volcanic eruption has strong claims to 

 credence. 



There can be no doubt that, whatever the prime cause, the 

 effects are due to the presence in the higher regions of our atmo- 

 sphere of aform of matl,r not usually there, at least to such 

 an extent. Now this matter, or form of matter, may, as far as 

 we know, be due to Krakatoa, to the earth's orbit traversing 

 streams or regions perv.adcd with extremely fine meteoric dust, 



or to any other cause that might either introduce new or alter 

 the form of existing matter. 



It is well known in the laboratory that certain chemical com- 

 binations and mechanical mixtures will exist as such, but in a 

 most unstable form, — a concussion or sharp sound, an electric 

 spark, &c., either breaks them up or brings about a change of 

 form so as to present altogether different physical properties. 

 Now it is also well known that at the time of the Krakatoa 

 eruption barometric pressure was spasmodically affected all 

 over the world. Everywhere where barographs have been re- 

 corded this fact appears. This atmospheric shudder, undoubtedly 

 originating at Krakatoa, was, I have reason to believe, conveyed 

 rapidly from the centre through the higher and more tenuous 

 regions of atmosphere, but afl"ected the lower strata in its pas- 

 sage. This would perhaps account for the immense distance — 

 thousands of miles — over which, it has been widely reported, 

 explosions were heard about the time of the occurrence of the 

 outburst. 



Now if we assume that on the peripheral regions of our atmo- 

 sphere gases and forms of matter exist in not very stable com- 

 binations or mixtures, it requires no great stretch of our imagina- 

 tion to picture the result of this great atmospheric shudder 

 bringing about an alteration in the form or proportion of matter, 

 and consequently such a change in its optical properties as to 

 produce the unusual and remarkable effects which have been so 

 universal. RoBT. J. Ellery 



Melbourne Observatory, February 27 



Under date of January 14 I named the bark C. Southard 

 HurWurt as having observed the glow on September 3. She 

 was dismasted in a cyclone August 8, and came to Honolulu 

 for repairs. On the former date she was in about lat. 17" N., 

 long. 125" W. The captain's wife, Mrs. Davis, described the 

 phenomena to me as extremely brilliant. 



Only last week I learned from Hon. H. M. Whitney, Post- 

 master-General, that on September 5 Mrs. Whitney and himself 

 distinctly observed the sun's disk before setting to be g>'een. 

 His residence was an exception to most of ours in Honolulu, 

 from which trees cut off a view of the horizon. My wife spoke 

 much that night of a strange green cumulus, seen by her ten 

 minutes before calling me to observe the portentous masses of 

 colour pouring out all over the sky. 



I beg special attention to my former remark of the "earth- 

 shadow sharply cutting off" the upper rim of the first glow. 

 This was very manifest in the strong heavy glows of September, 

 showing clearly that the first glow directly reflected the sun's 

 rays, while in the after-glow which had no defined upper rim, 

 but continued much longer, the haze reflects only the light of the 

 first glow. This bears on estimates of the height of the haze. 



Observers here are well agreed that during November there 

 was a very great abatement of the glows, amounting almost to a 

 cessation, although the whitish corona was always well developed 

 through the day. Early in December the glows were renewed, 

 and for six weeks continued quite as brilliant as during October. 

 They are now somewhat abated, although quite uniform nightly. 

 In September and October they were extremely unequal, as well 

 as varying in position of greater colour, south or north of west. 



As this revival of our glows closely followed their general 

 diffusion over Europe and the United States, I suggest that this 

 was the arrival in force by slow marches of the main body con- 

 stituting the great cone of vapours, which, falling into the atmo- 

 sphere in September, covered like a pall the Indian Ocean and 

 Peninsula, down the extended western slope of which cone the 

 light upper vapours were sent by the westward thrust of the 

 earth's rotation, to find speed in their downward slide to carry 

 them at once around the tropical belt as a light advance guard 

 (as set forth in my letter of January 14). ,As the September haze 

 Ijecame gradually dissipated, so the later December arrivals are 

 wasting away. S. E. Bishop 



Honolulu, January 30 



At Fanning's Island, long. 159° 22' W., lat. 3° 52' N., on 

 September 4 last, the proprietor, Mr. Greig, states that the sun 

 and sky had an extraordinary appearance; the sun "looked 

 like a copper kettle." Lurid colours covered the sky. Great 

 fears were felt for the safety of his schooner, the Jennie Walker, 

 which sailed three days before. 



From the master of the 7i««/c Walker Wt^^xv, th.at on Sep- 



