“ The mass of the powdery matter thrown out by the explosion of the twenty-seventh seems to have spread out at such an enormous altitude that the finer particles were forthwith conveyed by a full fair easterly gale steadily and without pause on a great circle of the globe. This lofty, unresting hurricane has been hitherto unsuspected. No means of ascertaining the winds of inaccessible altitudes in the tropics had been devised by human ingenuity. ”

“ There are craters fifteen times as large as the largest on our globe; there is the whole surface studded with cones as large as Vesuvius, a piled record of eruptions of tremendous force, and of internal energy so great that enormous circles, representing the walls of craters, overlap each other, and cracks extend for hundreds of miles from the volcanic centres. It is true that the largest circular walls on the moon's surface have been supposed to have been formed, not in the manner of the sides of terrestrial volcanoes, but by the sinking of the area within them ”

“ They have emerged from their quiet recesses with one accord to bear testimony to the truth of a scarcely credible tale. From forty-seven stations, fairly representing the whole civilized world, we learn that the wave spread out from Krakatoa as a centre, expanding in a circular form till half round the globe, concentrated again towards the Antipodes, whence it started afresh and travelled back to Krakatoa, occupying in the double journey thirty-six hours, rebounded, and set off again on the same revolution, and repeated the movement at least three times sufficiently strongly to be recorded. ”

“ Vast lakes of lava, too, seem to have extended over hundreds of square miles in Europe and America, as a consequence not of violent eruption, but of quiet extrusion. Possibly these deposits may resemble the so-called "seas" on the moon. There can be no doubt that most of the volcanoes of the earth are arranged on certain lines of weakness, but the pressure of solidified matter being much greater than on the moon, eruptive action has been more confined to particular areas. ”

“ A belt of trees such as oaks or pines will give an echo almost as sharply as a wall, and the noise of a train in passing by dense foliage is converted into a rushing sound of higher pitch, through the breaking up of large waves into smaller ones by numberless closely following reflections from the leaves successively encountered. ”

“ The abundance and size of craters testify to an effectual power of lunar volcanic action greatly exceeding anything with which we are familiar on the earth, but it must be borne in mind that, the force of gravity on the moon being only one-sixth of that of the earth, the height to which rocky matter would be thrown would be six times as great, and the crater walls proportionately extensive. ”

“ In a matter of human observation, nothing stands so much in the way of progress as the indolent habit of explaining the new and unknown by the old and familiar, the unreadiness to derive new ideas from new facts ”

“ The lava streams were more extensive than any single eruption had before produced in historic times, and their volume, according to Lyell, considerably exceeded that of Mont Blanc. Pumice covered the sea for long distances, and ashes fell in the north of Scotland. For months afterwards a thick dry mist spread over Europe. In Italy objects at a distance of three miles could not be distinguished, the sun was invisible near the horizon, and red or pale like the moon during the daytime, and the nights were strangely luminous. ”

“ We may here remark, as a matter of experience, that the neglect by the public of those grand natural spectacles, presented gratis, is quite astonishing, and that during one of the most striking of all the evening displays not one inhabitant of a large town on the south coast ventured on the beach to behold it. Everywhere shutters were closed at the customary hour, before the development of a scene which, if artificial, would have attracted thousands from distant nations, and which could not be expected to occur twice in a lifetime. ”

“ The volcanic dust consisted chiefly of this pumice reduced to the finest powder by being carried up by the gases escaping from the interior with explosive violence, and by the grinding together in the air of fragments rendered brittle by intense strain. The heaviest particles would fall near the volcano, the very light and friable glassy dust would be carried to great distances. This dust would be composed of the ultra-microscopical, the elongated, and the very thin particles, and being less basic in composition would be the most transparent. ”

“ The apparent objection, however, to Professor Judd's theory, arising from a consideration of the non-aqueous surface of the moon, is disposed of if we admit, what seems not at all improbable, that the water previously existing in the moon in a free state has been entirely absorbed by the rocky substance. The intermittent character of most eruptions, their sudden violence, and the nature of the matter ejected are very well explained by the new theory; problems at least as difficult remain for solution. ”

“ Another cause of periodic increases of pressure would be the shrinkage of the earth's crust upon the cooling interior, the percolation of water through fissures, and the closure of these fissures by changes of level, so that steam developed at some miles below the surface would force the fluid lava through the nearest volcanic vent. ”

“ The colors reflected by the particles would be those which had traversed with least loss the length of the stratum through which the sun shone, and later in the evening, in the case of the after-glow, those which had traversed the lower air — that is, the red and orange parts of the spectrum. The secondary glow, in their opinion, was caused by reflection of the rays of the first glow, as it sank, viewed from the high level, on the horizon. It is shown that an extremely small quantity of matter is sufficient to produce striking effects ”

“ The masses in appearance and structure exactly resemble the pumice ejected from Krakatoa. After fusion they are found to have lost from one to six per cent. of their weight. In examining the common pumice of Krakatoa it was found to have undergone a dilatation to five and a half times its original bulk, although something like one-tenth of the original lava consisted of undilatable crystals which remained to weight the mass. The obsidian or glassy rock has only to be heated in order to give off its volatile ingredients ”

“ The color of the sun's rays changed rapidly in passing though this cloud, from dark copper-color, through violet and crimson, to a brilliant azure blue. By experimenting under a variety of conditions a number of interesting changes of color were produced, and a very fair imitation of the remarkable colored rings, which were observed for nearly three years after the Krakatoa eruption. ”

“ But, considering the wave as a sonorous vibration of great intensity, it is remarkable that the rate to distances of two or three thousand miles in the tropics, where high temperature would favor rapidity of advance, did not much exceed the rate to much greater distances and to places in higher latitudes. One other factor would tend to increase velocity. Low notes are supposed to travel faster than high notes, and this wave might be considered as of a note far below the range of hearing. ”

“ During the whole of its rapid and wonderfully even revolution round the earth, the great cloud was extending itself less conspicuously towards the north and south, and many scattered observations in the temperate zones afford evidence that the sifting out of heavier particles continued without interruption, and that these, in sufficient quantity to produce moderate afterglow, were carried by the anti-trades and other elevated currents to great distances. ”

“ The coronæ, as we have seen, have been artificially produced by particles corresponding in size to those of the pumice cloud. From the conclusions reached by Professor Archibald and Mr. Russell in the optical sections, we learn that a cloud of fine dust may remain suspended at a height of from twenty-four down to thirteen miles without being sensibly affected by the weather of the lower atmosphere; that such a cloud in the tropics revolves round the earth from east to west in thirteen days; that it does not apparently condense vapor upon itself ”

“ On the waters of the sea, and especially in confined channels, such a difference of pressure must lead to a dangerous disturbance. The great rise in air pressure which undoubtedly took place above Krakatoa at the time of the ten o'clock explosion may have been due both to an actual wave of compression, of the nature of a sound-wave, and to the enormous quantity of gases and vapors projected to an immense height, and taking a considerable time to spread over the surrounding space. ”

“ So far as can be gathered therefore from the data, a general movement of the air within the tropics from east to west may be inferred, and without the tropics from west to east. Those waves which passed near the north and south poles give unaccountable results, for the direct wave from Krakatoa viâ the north pole does not seem to have been sensibly retarded by the low temperature, and the velocity of that which passed close to the south pole was only very decidedly reduced after the first passage, and in the next circuit was greatly increased. ”

“ The smaller vibrations in the vast concussions which reverberated above Krakatoa, being the only waves which would sensibly affect the ear, encountered so dense and wide a cloud of pumice, dust, and ashes in the air beneath that they were largely stopped and softened, and the detonations in the neighborhood of the volcano were thus rendered bearable, and, it seems, even less appalling than at greater distances. ”

“ Heated rocks which have long been subject to the hydration and aeration of infiltrated water would probably occupy more space in a solid than in a pasty or liquid condition, and would melt, as Professor Judd points out, at a lower temperature. Solid iron and solid bismuth will float on the melted metals, and solid lava floats on the liquid lake of a crater. [5] It is true that the contraction by cooling of the solidified part of the globe works in the opposite direction ”

“ It is shown that small transparent glassy particles are competent powerfully to reflect the sun's rays, and that the height of the stratum would cause the reflection of the beams of the setting sun to take place when the intervening air, including the greater part of what we call the blue sky, had been darkened by the shadow of the earth. ”

“ Stones and sand, which had been projected to an enormous height, covered up and destroyed almost everything within a radius of twenty miles. On the twelfth, another eruption of equal intensity followed, a large part of the mountain was broken off, and blocks of basalt were thrown to a distance of seven miles. By such manifestations, and the great number of craters within its area, Java came to be regarded as the chief focus of volcanic activity on the surface of the globe. ”

“ If small test-balloons could be constructed to remain for a definite time at heights from seventy to one hundred thousand feet, and to be brought down at will, interesting information would be gained respecting the eternally unclouded region within twenty miles of the habitable surface, and its system of regular currents of high velocity. In the distant future, when ballooning has attained a much higher stage of development, such knowledge may possibly be of practical value. ”

“ The comparison to the glare of a fire was made in almost every country where the fore-glows and after-glows appeared. At London, in Canada, for instance, the following language was used: On November 22 "most extraordinary sunset, pitch dark in east and zenith, a blaze of red lurid fire in west;" at Baltimore there was an appearance of a tremendous fire along the horizon, and at an altitude of 40o;" ”

“ By a very complete chain of evidence, due in great part to the observations which happened to have been undertaken by the captains of ships for the Meteorological Office in 1883, and to the excellent observations of the captains of German vessels, the connection between the phenomena which were observed in all parts of the world, viz., the haze in the sky, the colored sun, the coronæ, and the twilight illuminations, and the derivation of all these from Krakatoa, is established. ”

“ It is said that in some parts of the world the sunsets are habitually beautiful. In Italy and Egypt the rosy after-glow of the western sky in certain seasons is well known, but the coast of Peru and the ocean westward seem to surpass all other localities in their celestial scenery. ”

“ But the safe groundwork of facts always repays close attention. All through this inquiry we are reminded of the large results to be obtained by small but accurate instruments, and by a few careful measurements, rather than by numerous casual observations. ”

“ Moreover, the ancient crust of the earth, denuded of its stratified and earthy deposits, would exhibit some very large crater rings, many being now well known, and fissures hundreds of miles long seem to correspond with the far more conspicuous cracks and bright lines of the moon. ”

“ Thus the Ceylon observation, and perhaps Captain Vereker's near Labuan as well, would refer to cloud-streams of dust and steam, of no great magnitude, the one filtered out from a current going rapidly westwards, and the other carried by the S.W. monsoon towards Japan. The early arrival (twenty-eighth) in Japan of matter causing a coppery sun would be similarly due to the S.W. monsoon bearing the products of the twenty-sixth. ”