Some Curious and Startling Facts.

Star (Christchurch), Issue 5648, 18 June 1886, Page 3

Some Curious and Startling Facts.

[Spbcially writtbn foe the " Stae."] Our readers have been made familiar with the recent evente in the world-famed , Eotorua district ; they have been minutely informed as to the nature and extent of the convulsion of Nature there, so terrifying in its outburst, bo fatal in its results; and they have been enabled to come to the conclusion, from the statements made by men of scientific attainments, that in reality very little indeed ia known, aa to the cause of such phenomena. There are certain geological facts and certain laws of force upon which men may base their opinions. These opinions, however, differ ■widely, and remain mere conjectures. For ouraelves, we hold with Dr Hector that the explosive force which has buried Wairoa and the Native Bettlemente of Ariki and Morea, and has heaped up millions of cubio feet of mud as material for possible avalanches, waa caused by the sudden inletting of a body of water upon the subterranean heat, and the consequent generation of an enormous force of high-pressure steam. THIS SUBTERRANEAN HEAT IN THB EOTOBUA DISTRICT has always been abundantly evident. In the details which have from time to time been published relative to the hot springe there, the temperature is in some cases given as reaching the boiling point, 212deg Fan., whilst a heat of from 10 to 20deg less is not at all uncommon. And there is tte possibility — the strong probability, even — that the indications of volcanic activity in the North Island are simply one of the links in an immense chain of volcanic energy girdling the Pacific Ocean, and appearing here and there within its area of seventy-two million square miles. We may' trace this chain with considerable distinctness, commencing in the southward with those Antarctic outposts, Mounts Erebus and Terror ; through New Zealand j thence curving round the eastern coast of Australia ; still northward through islands innumerable ; through the Japan islands ; thence eastward via the Aleutians ; thence, following America's western coast-line southward to the Shetlands. The existence of thiß well-defined chain (with the known upheavals and subsidences within its area) gives rise and lends support to what we may term / THE SANDWICH ISLANDS THEORY, mentioned by our Wellington correspondent in one of his messages : a volcano in the Sandwich Islands died down j then a new volcanic cone rose out of the ocean between the Sandwich Islands and New Zealand ; then White Island, off our coast, became unusually active, and lastly Tarawera broke into eruption. The volcano which died down was Kilauea, in the south of the island of Hawaii j its crater has — or had — an inner circumference of seven miles, with a large lake of boiling lava therein. Yet this vast opening was but a subsidiary part of the volcano of Mauna Loa, "the largest and most remarkable in the world/ By some means this safety valve was shut down. Can we for one moment suppose that the pressure of the ocean on its bed, two, three, or more tons to the square inch, had no influence in forcing other vents, knowing as we do that the Pacific basin alters its levels, rising here, subsiding there P In point of fact, thpre may be a variety of agencies at work. The ocean pressure is one of these, and allied thereto is the BI'FECT OS' THE TIDES. Proctor and others have speculated upon what may have been, andwhat may be, the results of an increased weight of tidal water upon a shelving coast. If we roughly compare a section through an island to an arch, we may have upon certain points of that arch at stated times, such an increased pressure as may exercise a marked compressing effect, and may produce ruptnre6 in a volcanic earth- crust. Every foat of.' tidal riae, Professor Milne, the seistnological authority of Japan, tella us, is I " equivalent to a load being placed on the | area over which the tide takes place, of i bixty-two pounds to the square foot ; and the load is not evenly distributed, but stops abruptly at a coast-line." Professor Darwin, again assumes that these tidal loads may have much influence upon land areas which are in a more or less critical condition. New Zealand, it is specially interesting for us to note, is curiously formed. " The investigations of the 'Challenger' Expedition have shown that, unlike other Oceanic islands, New Zealand is surrounded by a submarine plateau or shelf, which extends in varying distance from the coast. .On the eouthwest the edge of this plateau almost coincides with the coast-line, which here presents a massive buttress of granitoid rocks to the prevailing erosive action of the ocean from that quarter. To the eastward, the extent of the plateau is unknown, except that it probably reaches as far as the Chatham Island. The depth of water i on the plateau ia about three hundred to J six hundred fathoms, the surrounding j water of the ocean having a depth of from two thousand to two thousand cix hundred j fathoms." This fact, as quoted, Dr Hector ! has given in one of his admirable hand- j books prepared for the Colonial Exhibition, i THE FItESBDItB OF THE AIB j is another factor that has to be borne in j mind. This pressure, as the barometer j every day reminds us, is a variable one. j Ordinarily it may be fourteen pounds to the square inch. Let the barometer rise an , inch, and we thereby know that upon every foot of ground there ha 3 been placed an increased pressure of not lees than j seventy pounds. Such an added pressure over the Continent of Australia, Mr Darwin ' haß calculated, would sink it two or three ! inches, aven though the earth were rigid as steel, which mostcertainly it ia not. We do not for one moment venture to assert that increased atmospheric pressure had to do with the Tarawera outburst, for the simple reason that scientific men differ quite aamuch on this point as on any other. But this much we may call attention to, that the season ha 3 been one of high barometers ; that oa June 9 the barometer was high, and was rising. It is one r f the items which system illoinvestigators of ike observed phenomena will of course consider*

THE BLE€TBICAL DIBPLAY een above Tarawera, on the night of th ruption, may — as Professor Bickerton has i uggeeted — have been caused by the roah- ! ing Bfceam. The production of torrente of electricity by the agency of a steam boiler and specially arranged jets, will be a vivid memory with people who have visited the now defunct Polytechnic in London. We have not touohed — aa some of our readers will doubtless have noticed— upon some of the seismic influences insisted upon and demonstrated with more or less clearness i by various authorities, nor can we, in view of the exigencies of newspaper space and time attempt to do so. But a very interesting feature indeed would be missed if the fact that EARTHQUAKE PREDICTIONS have been ventured upon were not stated. One of the prophets is Delauney, who bases his calculations upon the periodic theory. Just as there are fairly well defined years in which aun-Bpots are most numerous, so, Delauney holds, there are special years of earthquake, due to planetary influences ; Jupiter and Saturn being particularly referred to. Here are Delauney's predicted earthquake years:— lßß6 (!), 1891, 1898, 1900. Large meteoric showers, again, have i been supposed to have an earthquake connection j and men of Rudolph Falb's school rely upon the combined attractive force of I the sun and moon. Falb has been one of the modern prophets : "In 1873 he predicted the destructive earthquake of Belluno, which earned for himself a eulogistic poem. After this, in 1874, he predicted the eruption of Etna. He alao explained why, in b.c. 4000, there should have been a great flood, and for a.d. 6400 he predicts a repetition of such an occurrence." From all of which it is once more demonstrated that seismology (the Btudy of volcanic and earthquake phenomena) is a speculative science. But all is not pure speculation. In the Retomahana dißtrict, for example, the solvent nature of the spring waters, and the formation of great underground channels and chambers, is unmistakeable. Froude has noted in hia "Oceana" how rapidly the underlying flint is brought up and deposited on » the Burface, a rapidity which he has aptly , illustrated by the case of a still growing tree he saw there, its trunk partly encrusted with the glistening beauty of the White Terrace formation. Some of the springs deposit pure Bulphur ; some, lime in one form or another. The underground volcanic system of the North Island may be interrupted by rocks ; it may be in comparatively free communication with Kilauea of the Sandwich Islands. Speculation still, and still strangely mixed up with fact; for in the Sandwich Islands themselves "we see the columns of Lava in neighbouring mountains standing at different heights, indicating a want of subterranean connection between theße vente." Considering the frequency of earthquakes, the wonder is that we IN THIS ISLAND of Oceana, know so little of them. Yet we are credited by one authority with a monthly average of 28 perceptible ' ' shakes," most of these being, of course, bo insignificant that people generally would fail to notice them. In Japan, two shakes per day is the modest claim ; in the Andes, earthquakes occur at every instant of time. Occasionally— only occasionally — we have been able to notice a shake without difficulty. In the " Page of Southern history/* published the other day, we were told of a great earthquake forty years ago in the Waiau Valley. In 1855, on June 23, Wellington had a particularly sharp experience, and it is on record that many fish were then killed in consequence of the sulphurous vapours which rose in the sea near the coast. The shocks, in fact, came from the sea. It is curious that on the very same day North America had 'a rude shaking up, as did a part of the Austro-Hungarian territory ; and, within a few days, Japan was destructively visited. In 1868 there were notable shocks in New Zealand and New South Wales ; and of a subsequent quiver the spire of Christchurch Cathedral bears witness. In that spire an earthquake-recording pendulum was subsequently hung, but never hear anything about it. We have also experienced secondary effects. On May 9, 1877, some harbour towns on the coast of South America were destroyed, and a great wave carried death into Iquique ; 5641 miles that wave-motion travelled to Lyttelton, occupying only about 18* hours in doing so. In 1878, again, " earthquake- waye3 " ab: sorbed 25,000 liveß on the South American coast, crossed the Pacific, and "at the Chatham Islands rushed ■in with such violence that whole settlements were destroyed." But articles such as this must be deliberately cut to Borne definite length. We will close with A HUHOROUS ILLUSTRATION, but a perfectly true one, nevertheless, of the fact that in the study of earthquakes, as in numerous other things, the almondeyed disciples of Confucius have anticipated European civilisation. The extract with which we conclude is translated from the Chinese history, " Gokanjo" : — "In the first year of Yoka, a.d. 136, a Chinese called Choko invented a seismometer. [A drawing ia given.] This instrument consists of a spherically formed copper vessel, the diameter of which ia eight feet. It is covered at its top, and in form resembles a wine-bottle. Its outer part ia ornameated by the figures of different kinds of birds and animals, and old peculiar-looking letters. In the inner part of this instrument a column is co suspended that it can move in eight directions. [Part of the column projects through a circular opening in the top of the sphere.] Also, in the inside of the bottle, there is an arrangement by which some record of an earthquake ia made according to the movement of the pillar. On the outside of the bottle there are eight dragon heads, each of which holda a ball in its mouth. Underneath these heads there are eight frogs so placed that they appear to watch the dragon's face, so that they are ready to receive the ball if it should be dropped. All the arrangements which cause the pillar to knock the ball out of the dragon's mouth are well hidden in the bottle. When an earthquake occurs, aud the bottle is shaken, the dragon instantly drops the ball, and the frog which receives it vibrates vigorously." The particular ball dropped would of course indicate the direction of the earthwave. Choko did not labour in vain. His instrument ifl of interest, Professor Milne | remarks, on account of the close resemblance it bears to many of the instruments of modern times.