In this as in most other cases of volcanic disturbance, electrical phenomena were observed. One vessel in particular, while passing through the Sunda Straits, exhibited ‘balls of fire’ at her masthead and at the extremities of her yardarms. Further, it was noticed at the Oriental Telephone Station, Singapore, a place five hundred miles from Krakatoa, that on raising the receiving instrument to the ears, a perfect roar as of a waterfall was heard; and by shouting at the top of one’s voice, the clerk at the other end of the wire was able just to hear something like articulation, but not a single sentence could be understood. On the line to Ishore, which includes a submarine cable about a mile long, reports like pistol-shots were heard. These noises were considered due to a disturbance of the earth’s magnetic field, caused by the explosion, and reacting on the wires of the telephone.
We have now to refer to what has been a much debated question. From about September to the beginning of the present year, remarkable coronal appearances and sunglows were noticed in different parts of the world, and especially the somewhat rare phenomena of red, green, and blue suns. Observers such as Norman Lockyer, Dr Meldrum, and Helmholtz maintained that the phenomena were due to volcanic dust at a great altitude; others, and notably meteorologists, rejected this hypothesis, and urged that the coloured suns were due to unusually favourable atmospheric conditions, such colours being probably due to the refraction and reflection of light by watery vapours. But the theory that volcanic dust caused these appearances is fast gaining ground, if it be not already an incontrovertible fact. The spectroscope has shown that dust of almost microscopic fineness floating in the air caused the sun to appear red. Such dust has already fallen, and the microscope reveals the existence in it of salt particles. This, then, is fairly conclusive evidence of the volcanic origin of such dust. That ash particles were actually carried very far in the upper air-currents, has already appeared from snow which fell in Spain and rain in Holland, in which the same components were found as in the Krakatoa ashes. Dr Verbeek estimates that the height to which this fine matter was projected ‘may very well have reached’ forty-five to sixty thousand feet.
In a letter addressed to the Midland Naturalist by Mr Clement Wragge, of Torrens Observatory, Adelaide, South Australia, and dated July 17, 1884, the writer remarks that recently, when there were magnificent sunsets, he obtained ‘a perfectly sharp, clean spectrum without a trace of vapour-bands.’ And further, he is strongly of opinion that the Krakatoa eruption is the primary cause of these wondrous pictures in the Kosmos.
There can now be little doubt but that the green and blue suns and exceptional sunsets observed in Europe, India, Africa, North and South America, Japan, and Australia, were due to the Krakatoa eruption. The enormous volume of volcanic dust and steam shot up into the higher atmospheric zones by this convulsion are adequate to furnish the chromatic effects above mentioned.
But we have better evidence still: these peculiar solar effects followed a tolerably straight course to one which was in fact chiefly confined to a narrow belt near the equator; the data now collected show that on the second day after the eruption they appeared on the east coast of Africa, on the third day on the Gold Coast, at Trinidad on the sixth, and at Honolulu the ninth day. Finally, in a paper read by Dr Douglas Archibald at the late British Association meeting at Montreal, it was stated that ‘observations showed that the dates of the sunglows began earlier in Java, then apparently spread gradually away, the dust being so high as to be in the upper currents, of which we know little. These sunset glows were not seen before the eruption.... The dust appeared to have travelled at a uniform rate, over two thousand miles daily.’ ‘The topic,’ says Mr S. E. Bishop, writing from Honolulu, ‘is an endless one. Many ask what is the cause of frequent revivals of the red glows, such as the very fine one of August 19. It seems merely to show an irregular distribution of the vast clouds of thin Krakatoa haze still lingering in the upper atmosphere. They drift about, giving us sometimes more, sometimes less, of their presence. It is also not unlikely that in varying hygrometric conditions the minute dust-particles become nuclei for ice crystals of varying size. This would greatly vary their reflecting power, and accords with some observations of Mr C. J. Lyons, showing that the amount of red glow varies according to the prevalence of certain winds.’ Further facts are coming to hand respecting this great natural convulsion.
BY MEAD AND STREAM.
CHAPTER LV.—SWEET ARE THE USES OF ADVERSITY.
Soon after reading Mr Shield’s letter, Madge walked to Ringsford with Pansy. There had been a thaw during the night, and the meadows and the ploughed lands were transformed into sheets of dirty gray, dirty blue, and reddish slush, according to the character of the soil, dotted with patches of snow like the ghosts of islets in a lake of puddle. But the red sun had a frosty veil on his face; by-and-by this puddle would be glazed with ice, and the heavy drops of melting snow which were falling slowly from the trees would become glittering crystal pendants to their branches.
The two girls, their cheeks tingling with the bite of the east wind, tramped bravely through the slush, with no greater sense of inconvenience than was caused by the fact that they would be obliged to perform the journey by the road instead of taking the short-cut through the Forest.
They spoke little, for each was occupied with her own troublous thoughts; Pansy did not know much of the sources of her friend’s anxieties, and Madge had already exhausted the consolation she could offer to her companion. On arriving at Ringsford they found Sam Culver attending to his plants and greenhouses as methodically as if the mansion stood as sound as ever it had done and the daily supply of fruit and flowers would be required as usual.