,,the ,,wonder ,,book ,,of ,,volcanoes ,,and ,,earthquakes ,illustration3 ,,mount ,,vesuvius ,,in ,,eruption ,,the ,,wonder ,,book ,,of ,,volcanoes ,,and ,,earthquakes ,,by ,professor ,,edwin ,j4 ,,houston1 ,ph4,d4 ,,new ,,york ,,frederick ,a4 ,,stokes ,,company ,publishers ,copyright1 #aijg1 by ,,frederick ,a4 ,,stokes ,,company ,all rights reserved ,october1 #aijg ,,acknowledgments ,we take this opportunity of acknowledging the courtesy of the following publishers1 who have helped us in connection with the illustrations of this book3-- ,henry ,holt and ,company 7,physiography1 by ,rollin ,d4 ,salisbury74 ,d4 ,appleton and ,company 7,figs4 #ac1 #ce1 #ci1 #dj1 #da1 #db1 #dc1 #dd1 #de and #df1 ,volcanoes3 ,what ,they ,are and ,what ,they ,teach1 by ,j4 ,w4 ,judd2 ,fig4 #ae1 ,principles of ,geology1 by ,sir ,c4 ,lyell74 ,the ,american ,book ,company 7,manual of ,geology1 by ,james ,dwight ,dana74 ,g4 ,p4 ,putnam's ,sons 7,earthquakes in the ,light of the ,new ,seismology1 by ,c4 ,e4 ,dutton74 ,the ,clarendon ,press 7,geology3 ,chemical1 ,physical1 and ,stratigraphical1 by ,joseph ,prestwich74 ,,the ,,publishers4 ,,contents ,,chapter ,,page ,i4 ,,the ,,volcanic ,,eruption ,,of ,,krakatoa ,,in #ahhc #a ,,ii4 ,,some ,,effects ,,of ,,the ,,eruption ,,of ,,krakatoa #ab ,,iii4 ,,the ,,volcanic ,,island ,,of ,,hawaii #bf ,,iv4 ,,the ,,volcanic ,,island ,,of ,,iceland #df ,v4 ,,vesuvius #eh ,,vi4 ,,other ,,volcanoes ,,of ,,the ,,mediterranean #gc ,,vii4 ,,orizaba1 ,,popocatepetl1 ,,ixtaccihuatl1 ,,and ,,other ,,volcanoes ,,of ,,mexico #he ,,viii4 ,,coseguina ,,and ,,other ,,volcanoes ,,of ,,central ,,america #ia ,,ix4 ,,the ,,volcanic ,,mountains ,,of ,,south ,,america #ig ,x4 ,,volcanoes ,,of ,,the ,,united ,,states #aje ,,xi4 ,,the ,,catastrophe ,,of ,,martinique ,,and ,,the ,,volcanic ,,islands ,,of ,,the ,,lesser ,,antilles #aag ,,xii4 ,,some ,,other ,,noted ,,volcanic ,,mountains #abe ,,xiii4 ,,jorullo1 ,a ,,young ,,volcanic ,,mountain #acj ,,xiv4 ,,mid-,,ocean ,,volcanic ,,islands #acg ,,xv4 ,,submarine ,,volcanoes #ada ,,xvi4 ,,distribution ,,of ,,the ,,earth',s ,,volcanoes #adh ,,xvii4 ,,volcanoes ,,of ,,the ,,geological ,,past #aec ,,xviii4 ,,laplace',s ,,nebular ,,hypothesis #aeg ,,xix4 ,,the ,,earth',s ,,heated ,,interior1 ,,the ,,cause ,,of ,,volcanoes #afe ,,xx4 ,,some ,,forms ,,of ,,lava #agh ,,xxi4 ,,mud ,,volcanoes ,,and ,,hot ,,springs #aic ,,xxii4 ,,the ,,volcanoes ,,of ,,the ,,moon #bjg ,,xxiii4 ,,earthquakes #bai ,,xxiv4 ,,some ,,of ,,the ,,phenomena ,,of ,,earthquakes #bca ,,xxv4 ,,the ,,earthquake ,,of ,,calabria ,,in #aghc #bde ,,xxvi4 ,,the ,,great ,,lisbon ,,earthquake ,,of #agee #beb ,,xxvii4 ,,the ,,earthquake ,,of ,,cutch1 ,,india1 ,,in #ahai #beg ,,xxviii4 ,,the ,,san ,,francisco ,,earthquake ,,of ,,april #ah1 #aijf #bfb ,,xxix4 ,,some ,,other ,,notable ,,earthquakes #bfi ,,xxx4 ,,sodom ,,and ,,gomorrah ,,and ,,the ,,cities ,,of ,,the ,,plain #bha ,,xxxi4 ,,instruments ,,for ,,recording ,,and ,,measuring ,,earthquake ,,shocks #bij ,,xxxii4 ,,seaquakes #bif ,,xxxiii4 ,,the ,,distribution ,,of ,,earthquakes #cjc ,,xxxiv4 ,,the ,,causes ,,of ,,earthquakes #cjh ,,xxxv4 ,,earthquakes ,,of ,,the ,,geological ,,past--,,cataclysms #cai ,,xxxvi4 ,,the ,,kimberly ,,diamond ,,fields ,,and ,,their ,,volcanic ,,origin #cbf ,,xxxvii4 ,,the ,,fabled ,,continent ,,of ,,atlantis #cce ,,xxxviii4 ,,plato',s ,,account ,,of ,,atlantis #cdd ,,xxxix4 ,,nature',s ,,warning ,,of ,,coming ,,earthquakes #cfd ,,full ,,page ,,illustrations ,,page ,,mt4 ,,vesuvius ,,in ,,eruption ,frontispiece ,,stones ,,and ,,lava ,,thrown ,,upwards--,,eruption ,,of ,,mokuaweoweo1 ,,hawaii1 ,,july #d-ba1 #ahii fac4 #cf ,,cotopaxi #ajb ,,the ,,lava ,,flow ,,of ,,the ,,crater ,,of ,,kilauea1 ,,hawaiian ,,islands #ahd ,a ,,san ,,francisco ,,pavement ,,torn ,,by ,,the ,,earthquake #bff ,,illustrations ,,in ,,text ,,fig4 ,,page #a4 ,,the ,,sunda ,,islands #c #b4 ,,krakatoa ,,before ,,the ,,eruption #d #c4 ,,krakatoa ,,after ,,the ,,eruption #d #d4 ,,volcanic ,,dust ,,as ,,it ,,appears ,,under ,,the ,,microscope #ai #e4 ,,the ,,hawaiian ,,islands #bg #f4 ,,hawaii #bi #g4 ,,panorama ,,of ,,mokuaweoweo #ce #h4 ,,view ,,of ,,the ,,crater ,,of ,,kilauea ,,from ,,the ,,volcano ,,house #ce #i4 ,,crater ,,of ,,kilauea #dj #aj4 ,,sections ,,of ,,kilauea ,,at ,,different ,,periods #db #aa4 ,,iceland #dg #ab4 ,,the ,,mediterranean #ei #ac4 ,,the ,,volcanic ,,district ,,around ,,vesuvius #fj #ad4 ,,mt4 ,,etna #gg #ae4 ,,stromboli1 ,,viewed ,,from ,,the ,,northwest1 ,,april1 #ahgd #gi #af4 ,,mexico ,,and ,,central ,,america #hf #ag4 ,,south ,,america #ih #ah4 ,,the ,,united ,,states #ajf #ai4 ,,panorama ,,from ,,the ,,mesa ,,at ,,the ,,edge ,,of ,,mt4 ,,taylor #aaj #bj4 ,,volcanic ,,necks1 ,,edge ,,of ,,mesa ,,at ,,mt4 ,,taylor #aaa #ba4 ,,the ,,lesser ,,antilles #aah #bb4 ,,graham',s ,,island--,a ,,recent ,,volcanic ,,island #adc #bc4 ,,aleutian ,,islands #adf #bd4 ,,map ,,of ,,the ,,world1 ,,showing ,,location ,,of ,,active ,,and ,,recently ,,extinct ,,volcanoes #aej #be4 ,,volcanic ,,vesicles #ahc #bf4 ,,thread-,,lace ,,scori ,,from ,,kilauea #ahe #bg4 ,,thread-,,lace ,,scori ,,from ,,kilauea #ahe #bh4 ,,frost-,,like ,,lava ,,crystals #ahg #bi4 ,,frost-,,like ,,lava ,,crystals #ahg #cj4 ,,basaltic ,,columns1 ,,isle ,,of ,,cyclops1 ,,italy #ahh #ca4 ,,columnar ,,and ,,non-,,columnar ,,basalt #ahi #cb1 #cc4 ,,driblet ,,cones #aij #cd4 ,,lava ,,stalactites #aia #ce4 ,,crater ,,of ,,the ,,great ,,geyser ,,of ,,iceland #bjb #cf4 ,,giant ,,geyser #bjc #cg4 ,,bee ,,hive #bjc #ch4 ,,bee ,,hive ,,geyser ,,of ,,iceland #bje #ci4 ,,heavy ,,stone ,,obelisks ,,twisted ,,by ,,calabrian ,,earthquake ,,of #aghc #bbi #dj4 ,,circular ,,hollow ,,formed ,,by ,,calabrian ,,earthquake #bci #da4 ,,section ,,of ,,circular ,,hollow ,,formed ,,by ,,calabrian ,,earthquake #bci #db4 ,,map ,,of ,,the ,,calabrian ,,earthquake ,,of #aghc #bdf #dc4 ,,fissures ,,caused ,,by ,,the ,,calabrian ,,earthquake #bdi #dd4 ,,map ,,showing ,,district ,,visited ,,by ,,the ,,earthquake ,,of ,,cutch ,,of #ahai #beh #de4 ,,sindree ,,before ,,the ,,earthquake ,,of #ahai #bei #df4 ,,sindree ,,after ,,the ,,earthquake ,,of #ahai #bfj #dg4 ,,map ,,of ,,western ,,coast ,,of ,,california ,,showing ,,position ,,of ,,san ,,francisco #bfc #dh4 ,,new ,,zealand #bgd #di4 ,,map ,,showing ,,region ,,affected ,,by ,,the ,,charleston ,,earthquake ,,of #ahhf #bgg #ej4 ,,syria #bhb #ea4 ,,complex ,,record ,,of ,,seismograph #bic #eb4 ,,long ,,distance ,,seismogram #bic #ec4 ,,vicentini ,,vertical ,,pendulum #bid #ed4 ,,vicentini ,,pendulum ,,and ,,recorder #bie #ee4 ,,davison',s ,,earthquake ,,map ,,of ,,japan #cjf ,,the ,,wonder ,,book ,,of ,,volcanoes ,,and ,,earthquakes ,,the ,,wonder ,,book ,,of ,,volcanoes ,,and ,,earthquakes ,,chapter ,i ,,the ,,volcanic ,,eruption ,,of ,,krakatoa ,,in #ahhc ,krakatoa is a little island in the ,straits of ,sunda1 about thirty miles west of the island of ,java1 and nearly the same distance east of the island of ,sumatra4 ,it is uninhabited and very small1 measuring about five miles in length and less than three miles in width4 ,its total area is only thirteen square miles4 ,this little piece of land made itself famous by what took place on it during the month of ,august1 #ahhc4 ,krakatoa is one of the many islands that form the large island chain known as the ,sunda ,islands4 ,the most important islands of this chain are ,sumatra1 ,java1 ,sumbawa1 ,flores1 and ,ceram4 ,between ,sumatra and ,java1 the largest two of these islands1 there is a channel called the ,straits of ,sunda that connects the waters of the ,indian ,ocean with those of the ,pacific ,ocean4 ,the ,straits of ,sunda is an important piece of water that forms one of the great highways to the ,east4 ,shipping is1 therefore1 always to be found in its waters4 ,as can be seen by the map1 ,krakatoa is not far from the ,equator1 being situated in lat4 #f #g' ,s4 and long4 #aje #bf' ,e4 from ,greenwich4 ,since there are about sixty-nine miles in every degree of latitude1 ,krakatoa is about #dbj miles south of the ,equator1 and is about twenty-five miles from ,java4 ,java is part of the ,dutch ,east ,indies1 which includes ,java1 ,celebes1 the ,spice ,islands1 and parts of ,borneo and ,sumatra4 ,batavia1 the principal seaport of ,java1 near the northwest coast1 is a great shipping centre1 visited by vessels from nearly all parts of the world4 ,it has1 however1 no harbor1 but is approached from the ocean by means of a canal two miles in length1 the sides of which are provided with massive brick walls4 ,besides ,batavia1 which is situated about one hundred ,english miles east of ,krakatoa1 there are many smaller towns or villages1 the most important of which is ,anjer1 a thriving seaport town1 where sailing vessels obtain their supplies of food and fresh water4 ,before the eruption of ,krakatoa1 ,anjer was provided with a strong1 stone lighthouse4 ,java is especially noted for its production of coffee1 in which it is second only to ,brazil4 ,its area is about the same as that of the ,state of ,new ,york4 ,java is one of the most densely populated parts of the world1 containing nearly four times as many people as the whole ,state of ,new ,york4 ,these facts about the situation and surroundings of ,krakatoa are necessary to an understanding of the wonderful thing that happened on it during the month of ,august1 #ahhc4 ,in that month ,krakatoa suffered a most tremendous explosive volcanic eruption1 for it is a volcano4 ,illustration3 ,,fig4 #a4 ,,the ,,sunda ,,islands ,a volcano is a mountain or hill1 generally conical in shape1 having at the top a nearly central opening1 called a crater1 from which at times melted rock and lava1 vapor and gases escape4 ,the lava either flows down the side of the mountain in a liquid condition1 or is thrown upwards into the air4 ,if the distance the lava is thrown upwards is sufficiently great the melted matter solidifies before it falls to the earth4 ,in such cases the largest fragments form what are called volcanic cinders1 the smaller pieces1 volcanic ashes1 and the extremely small particles1 volcanic dust4 ,if1 however1 the lava is thrown to a comparatively small height1 it is still melted when it falls1 and is then known as volcanic drops or driblets4 ,illustration3 ,,fig4 #b4 ,,krakatoa ,,before ,,the ,,eruption ,it is not surprising that ,krakatoa is a volcanic island1 since it lies in one of the most active belts of volcanic islands in the world1 and near the coasts of the most active of these islands2 i4 e41 ,java4 ,this belt1 as shown in the map1 includes1 besides the ,sunda ,island chain1 parts of ,gilolo1 ,celebes1 ,mindanao and the ,philippine ,islands4 ,these islands lie between ,asia on the northwest and ,australia on the southeast4 ,illustration3 ,,fig4 #c4 ,,krakatoa ,,after ,,the ,,eruption ,there is no other part of the world with1 perhaps1 the single exception of ,japan1 where so many active volcanoes are crowded in so small a space4 ,the island of ,java1 small as it is1 has nearly fifty volcanoes1 of which at least twenty-eight are active4 ,they are situated in a lofty range running from east to west1 some of the peaks of which are more than #aj1jjj feet above the level of the sea4 ,volcanic eruptions are so frequent that the island is seldom free from them4 ,as will be seen from the map shown in ,fig4 #b1 ,krakatoa consists of three groups of volcanic mountains1 the southern group giving the name of ,krakatoa to the island4 ,strictly speaking1 this mountain was called ,rakata1 but as it is now generally known as ,krakatoa1 it would be unwise to attempt to call it by any other name4 ,the central mountain or group of mountains is known as ,danan1 and consists largely of part of an old crater4 ,the group of mountains which lies near the northern end of the island was known as ,perboawatan4 ,from the centre of this latter group of mountains are several old lava streams consisting of a variety of lava resembling a dark-colored glass1 known to mineralogists as obsidian1 or volcanic glass4 ,although ,krakatoa was always a volcano1 yet between the years #afhj and #ahhc1 it was in the condition of a sleeping or extinct volcano4 ,there had been a severe explosive eruption in the year #afhj1 that caused great loss of life and property1 but ever since that time all activity had ceased and it seemed that the volcano would never again burst out4 ,in other words1 it was generally regarded as a trustworthy1 sedate1 quiet1 inoffensive and perfectly safe volcano1 that had become extinct4 ,the long continued quiet of ,krakatoa was broken on the #bjth of ,may1 #ahhc1 when the inhabitants of ,batavia on the island of ,java were terrified by noises like the firing of great guns1 that were first heard between ten and eleven o'clock in the morning4 ,these noises were accompanied by the shaking of the ground and buildings4 ,the sleeping volcano of ,krakatoa was evidently growing restless1 but no great damage was done and soon all was again quiet4 ,the disturbances were merely the forerunner of the terrible eruption soon to follow1 and confidence was soon restored4 ,but suddenly1 on ,sunday1 ,august #bfth1 #ahhc1 almost without any further warnings1 ,krakatoa burst into terrible activity and began an explosive eruption that has never been equalled in severity in the memory of man4 ,that memorable ,sunday of ,august #bfth1 #ahhc1 came during a season of the year known as the dry monsoon1 a name given the season of the periodical winds from the ,indian ,ocean4 ,batavia1 and the surrounding country1 greatly needed rain1 for in this part of the world it seldom rains from ,april to ,october1 although the air is very moist and damp4 ,for this reason the beginning of the wet season is always welcomed4 ,when1 therefore1 the rumbling sounds of the approaching catastrophe of ,krakatoa were heard in ,batavia1 the people1 believing that the noises were due to peals of thunder1 rejoiced1 for all thought they heralded an earlier setting in of the wet monsoon4 ,but when the rumbling sounds increased and reports were heard like heavy artillery1 it was clear that the sounds were the beginning of a volcanic eruption1 a phenomenon with which they were only too well acquainted1 but1 as volcanic eruptions were far from being uncommon in ,java1 no one was very greatly frightened4 ,but this time the noises increased to such an extent that the people became alarmed4 ,throughout the night the appalling sounds continued and were accompanied by shakings of the earth sufficiently strong to shake the houses violently4 ,sleep was out of the question4 ,many of the people left their houses and remained all night in the open air1 fearing the shocks would bring the houses down over their heads4 ,the morning instead of heralding the dawn of a beautiful tropical day1 with its bright1 cheerful sunlight1 brought with it skies covered with gray clouds that completely hid the sun4 ,the rumbling sounds1 however1 had decreased1 and the people were beginning to congratulate themselves that the dangers were over1 when suddenly1 the sky grew darker1 and there began a shower of ashes that soon covered the streets and houses of the city4 ,about seven o'clock on the morning of ,august #bgth1 a most tremendous crash was heard4 ,the sky rapidly became so dark that it was soon necessary to light the lamps in the houses of ,batavia1 and some of the neighboring towns in the western part of ,java4 ,in addition to this the air was filled with vapor1 while every now and then earthquake shocks were again felt4 ,these shocks were accompanied by terrific noises like those produced by the explosion of heavy artillery4 ,the noises rapidly increased in number and intensity until they produced a nearly continuous roar1 the nature of which it is almost impossible to describe since it is probable that such sounds had never been heard before by man4 ,it is a curious fact1 which1 ,i believe1 has never been satisfactorily explained1 that in most cases the people in the immediate neighborhood of the volcano1 as1 for example1 those on board vessels in the ,straits of ,sunda1 did not hear the terrific noises at all4 ,possibly they were too loud and simply gave a single inward impetus to the drum of the ear and then held it in position4 ,probably some of my readers may remember that witty description given by ,dr4 ,oliver ,wendell ,holmes of an alleged effort made by all the people of the world to find out whether or not there is a man in the moon4 ,this wonderful plan was as follows3 ,careful calculations were made to ascertain when it would be the same time over all the earth so that all the people of the earth could simultaneously shout at the top of their voices4 ,in this way it was hoped that the man in the moon1 if there were such a person1 would notice the noise4 ,the story goes on to tell how when the time approached for the great experiment1 and all were ready to shout as loud as they could1 that each person reasoning to himself or herself1 that amid so great a noise no one could notice whether his or her voice was omitted1 determined to remain silent1 so as to be able to hear the noise and the better to observe what the man in the moon would do when the sound reached him4 ,the result was that every person on the earth remained silent and simply listened1 so that the earth was never so quiet before4 ,had ,oliver ,wendell ,holmes1 or any other person conceiving the witty idea1 lived during the time of the great explosive eruption of ,krakatoa1 on that memorable ,august #bgth1 #ahhc1 he might have taken the opportunity of observing the man in the moon1 had he not been frightened by what was occurring1 for certainly never before were such tremendous or terrifying sounds produced1 for these sounds1 as we shall see shortly1 were actually heard for distances of more than #c1jjj miles from the volcano4 ,there were two different kinds of waves produced in the air by the tremendous forces at work in the eruption of ,krakatoa2 namely1 atmospheric waves and sound waves4 ,the atmospheric waves showed their presence in the air by means of changes produced in the atmospheric pressure4 ,now1 while these changes cannot readily be felt by man1 yet their presence can be easily shown by the use of instruments called barometers4 ,there are in different parts of the world1 buildings called meteorological observatories1 that are provided1 among other instruments1 with recording barometers4 ,these instruments caught the great atmospheric waves that were produced by the eruption of ,krakatoa4 ,in this manner1 the astounding fact was learned that the waves starting from the volcano travelled no less than seven times around the world4 ,when we say astounding1 it must not be understood that the formation of such waves was at all contrary to the known laws of physics4 ,on the contrary1 provided the force of the eruption was sufficiently great1 such waves must have been produced in the great rial ocean4 ,the astonishing1 or wonderful thing1 was that the force setting up these waves was so great that it caused them to move seven times around the globe4 ,the atmospheric waves were so powerful that it will be worth our while to describe them in detail4 ,starting from the volcano of ,krakatoa1 as a centre1 these waves moved outwards in all directions1 becoming gradually larger and larger until they reached a point halfway round the globe1 or #ahj from ,krakatoa4 ,the waves did not1 however1 stop here1 but continued moving onward1 now growing smaller and smaller until they reached a point in ,north ,america1 immediately opposite ,krakatoa4 ,such a point on a globe is called an antipodal point4#a ,the waves did not stop at this point1 but again advanced moving toward ,krakatoa1 growing larger and larger until they again reached a point halfway around the globe1 or #ahj from ,krakatoa1 when they again continued moving but now continually growing smaller and smaller1 until they reached ,krakatoa4 ,here they again began moving completely around the globe1 and this was continued for as many as seven times4 ,it must not be supposed that the waves ceased on the seventh time around4 ,on the contrary1 they1 probably1 kept on moving for many additional times1 but they were then so feeble that even the sensitive recording barometers were unable to detect their presence4 ,there was another kind of waves in the atmosphere that did not require barometers for their detection4 ,these were the sound waves1 and can readily be detected by the human ear4 ,now1 in the case of the great eruption of ,krakatoa1 the intensity of the sounds was so great that the sounds could be heard distinctly at distances of several thousand miles from ,krakatoa4 ,the sound waves so closely resembled the explosion of artillery that at ,acheen1 a port on the northern coast of ,sumatra1 #a1jgc miles from ,krakatoa1 the authorities1 believing that an attack was being made on the port1 placed all their troops under arms to repel the invaders4 ,the sounds were also distinctly heard at ,bangkok1 in ,siam1 a distance of #a1dac miles from the volcano4 ,they were also heard at the ,chagos ,islands1 a group of islands situated in the ,indian ,ocean about #b1bfg miles from ,krakatoa4 ,two steamers at ,singapore1 #ebb miles distant1 were despatched to find the vessel that was believed to be firing guns as distress signals4 ,the sounds were distinctly heard in parts of ,south ,australia1 #b1ajj miles distant1 and in ,western ,australia1 at #a1gjj miles distance4 ,but it will be unnecessary to give any further details of the great distances at which these sounds were actually heard4 ,it will suffice to say that they were heard as far off as about #c1jjj miles4 ,it is difficult to picture to one's self such great distances4 ,assuming the greatest distances to be in the neighborhood of #c1jjj miles1 it would be as if a sound produced1 say1 in ,boston1 ,new ,york1 or ,philadelphia1 was so loud that it could be heard in ,amsterdam1 ,london1 or ,paris4 ,some idea of the intensity of these sounds can be had from the fact that in ,batavia1 when1 in accordance with usage1 a gun was fired from one of the forts at eight o'clock in the morning1 two hours before the greatest intensity of the sounds had been reached1 the sound of the gun could scarcely be heard above the continuous roar4 ,while1 of course1 the principal reason the sound waves were carried so far was the great force causing the eruption1 yet these distances were increased by the fact that the explosion occurred in a region almost entirely surrounded by great bodies of water4 ,the waves could1 therefore1 be readily carried along the surface of the sea4 ,had there been a high mountain wall1 like the ,andes of ,south ,america1 on one side of the volcano they would probably have been shut off in this direction a short distance from where they were produced4 ,,chapter ,,ii ,,some ,,effects ,,of ,,the ,,eruption ,,of ,,krakatoa ,besides the sound waves in the air1 there were waves in the waters of the ocean4 ,suddenly1 without any warning1 the people of ,batavia were surprised by a huge wave that1 crossing the ,straits of ,sunda1 entered the ship canal before referred to as connecting the city with the ocean1 and1 rising above the brick wall1 poured over the surrounding country4 ,although ,batavia was #ajj ,english miles from ,krakatoa1 yet after travelling this distance the wave was sufficiently strong to enter the city and flood its streets with water to a depth of several feet4 ,fortunately1 the loss of life was small in the city of ,batavia1 but very great in the surrounding towns and villages4 ,the ocean waves varied in height at different times of the eruption4 ,the greatest were from fifty to eighty feet high4 ,just imagine the effect of a wave twice the height of an ordinary house4 ,the waves caused great damage to the shipping in the neighborhood4 ,in one instance1 a vessel was carried one and a half miles inland and left on dry land thirty feet above the level of the sea4 ,the total loss of life by the waves has been estimated at #ce1jjj people2 besides this1 of course1 there was a great amount of property destroyed4 ,the greatest loss was in the immediate neighborhood of ,krakatoa4 ,gigantic waves swept over the lowlands lying near the shores of ,sumatra and ,java1 where over areas several miles in width nearly everything was destroyed1 the houses1 trees1 and people being swept away and the surface of the land greatly changed4 ,the towns of ,karang and ,anjer1 as well as numerous smaller villages1 were almost completely destroyed4 ,the seaport town of ,anjer1 by far the most important of the above towns1 was almost completely swept away4 ,the heavy stone lighthouse was so completely obliterated that no traces of its heavy stone foundations could afterwards be found4 ,the ,rev4 ,phillip ,neale1 formerly a ,british chaplain at ,batavia1 from whose account of the eruption of ,krakatoa some of the above facts have been taken1 tells of the brave action of the keeper of the lighthouse at ,anjer4 ,besides his work as lighthouse keeper1 to see that the light was constantly burning during the night1 he was charged with telegraphing to ,batavia the names of all passing vessels4 ,on the fateful morning of the great catastrophe1 observing that the sun did not rise1 he kept the light of the lighthouse burning1 and1 notwithstanding the danger to which he was exposed1 continued at his post in order to send word to ,batavia of the passing of an ,english steamer4 ,while doing this the lighthouse was swept away and the brave man perished4 ,the following verbal account of the destruction of the port of ,anjer was given by a ,dutch pilot stationed at ,anjer4 ,this description is quoted by the ,rev4 ,mr4 ,neale from an article prepared by him for publication in ,the ,leisure ,hour4 ,i have lived in ,anjer all my life1 and little thought the old town would have been destroyed in the way it has4 ,i am getting on in years1 and quite expected to have laid my bones in the little cemetery near the shore1 but not even that has escaped and some of the bodies have actually been washed out of their graves and carried out to sea4 ,the whole town has been swept away1 and ,i have lost everything except my life4 ,the wonder is that ,i escaped at all4 ,i can never be too thankful for such a miraculous escape as ,i had4 ,the eruption began on the ,sunday afternoon4 ,we did not take much notice at first1 until the reports grew very loud4 ,then we noticed that ,krakatoa was completely enveloped in smoke4 ,afterwards came on the thick darkness1 so black and intense that ,i could not see my hand before my eyes4 ,it was about this time that a message came from ,batavia inquiring as to explosive shocks1 and the last telegram sent off from us was telling you about the darkness and smoke4 ,towards night everything became worse4 ,the reports became deafening1 the natives cowered down panic-stricken1 and a red1 fiery glare was visible in the sky above the burning mountain4 ,although ,krakatoa was twenty-five miles away1 the concussion and vibration from the constantly repeated shocks were most terrifying4 ,many of the houses shook so much that we feared every minute would bring them down4 ,there was little sleep for any of us that dreadful night4 ,before daybreak on ,monday1 on going out of doors1 ,i found the shower of ashes had commenced1 and this gradually increased in force until at length large pieces of pumice stone kept falling around4 ,about six ,a4 ,m4 ,i was walking along the beach4 ,there was no sign of the sun1 as usual1 and the sky had a dull1 depressing look4 ,some of the darkness of the previous day had cleared off1 but it was not very light even then4 ,looking out to sea ,i noticed a dark1 black object through the gloom1 travelling towards the shore4 ,at first sight it seemed like a low range of hills rising out of the water1 but ,i knew there was nothing of the kind in that part of the ,sunda ,strait4 ,a second glance--and a very hurried one it was--convinced me that it was a lofty ridge of water many feet high1 and worse still1 that it would soon break upon the coast near the town4 ,there was no time to give any warning1 and so ,i turned and ran for my life4 ,my running days have long gone by1 but you may be sure that ,i did my best4 ,in a few minutes ,i heard the water with a loud roar break upon the shore4 ,everything was engulfed4 ,another glance around showed the houses being swept away and the trees thrown down on every side4 ,breathless and exhausted ,i still pressed on4 ,as ,i heard the rushing waters behind me1 ,i knew that it was a race for life4 ,struggling on1 a few yards more brought me to some rising ground1 and here the torrent of water overtook me4 ,i gave up all for lost1 as ,i saw with dismay how high the wave still was4 ,i was soon taken off my feet and borne inland by the force of the resistless mass4 ,i remember nothing more until a violent blow aroused me4 ,some hard1 firm substance seemed within my reach1 and clutching it1 ,i found ,i had gained a place of safety4 ,the waters swept past1 and ,i found myself clinging to a cocoanut palm-tree4 ,most of the trees near the town were uprooted and thrown down for miles1 but this one fortunately had escaped and myself with it4 ,the huge wave rolled on1 gradually decreasing in height and strength until the mountain slopes at the back of ,anjer were reached1 and then1 its fury spent1 the water gradually receded and flowed back into the sea4 ,the sight of those receding waters haunts me still4 ,as ,i clung to the palm-tree1 wet and exhausted1 there floated past the dead bodies of many a friend and neighbor4 ,only a mere handful of the population escaped4 ,houses and streets were completely destroyed1 and scarcely a trace remains of where the once busy1 thriving town originally stood4 ,unless you go yourself to see the ruin you will never believe how completely the place has been swept away4 ,dead bodies1 fallen trees1 wrecked houses1 an immense muddy morass and great pools of water1 are all that is left of the town where my life has been spent4 ,my home and all my belongings of course perished--even the clothes ,i am wearing are borrowed--but ,i am thankful enough to have escaped with my life and to be none the worse for all that ,i have passed through4 ,as is common in cases of earthquake waves a great depression in the level of the sea occurred at places great distances from ,krakatoa4 ,for example1 at the harbor of ,ceylon1 the water receded so far that for about three minutes the boats were left high and dry1 and then a huge wave carried them with it as it rushed over the land4 ,perhaps one of the best evidences of the immense power of ocean waves is to be seen in the massive blocks of white coral rock that were washed up by the waves1 on parts of the coast of ,java for distances of from two to three miles from the ocean4 ,many of these blocks weighed from twenty to thirty tons4 ,indeed1 some of them reached the weight of from forty to fifty tons4 ,it is probable that the island of ,krakatoa and its neighboring smaller islands formed portions of a huge cone about eight miles in diameter1 that has been broken up at some very remote but unknown time by1 perhaps1 a greater catastrophe than that of ,august1 #ahhc4 ,in the ,straits of ,sunda the water was raised fifty feet to eighty feet above the ordinary level1 and produced tremendous destruction especially on the coasts of ,java and ,sumatra1 sweeping away many villages and drowning many thousands of people4 ,the wave had a velocity of progression of nearly #djj miles per hour1 or eight times faster than an ordinary express train4 ,when it is said that the velocity of progression of the wave was nearly #djj miles per hour1 it is not meant that a body floating on the ocean1 such1 for example1 as a ship1 would have been carried forward at this high velocity1 but would merely rise and fall in a to-and-fro swing to about the height of the wave2 that is1 fifty to eighty feet according to what may have been the height4 ,as in the case of the sound waves these motions of water covered or passed over nearly all the waters of the earth4 ,the waves progressing toward the west1 crossed the ,indian ,ocean reaching to the coast of ,hindostan1 and ,madagascar1 and sweeping around the southern part of ,africa1 finally reached the coasts of ,france and ,england1 as well as the eastern part of ,north and ,south ,america4 ,sweeping towards the east1 they reached the coasts of ,australia1 ,new ,zealand1 and crossing the vast ,pacific ,ocean were felt at ,alaska and the western coasts of ,north and ,south ,america4 ,but besides the enormous waves caused by the eruption1 there were marked changes in the level of the land4 ,large portions of the coast of ,sumatra and ,java were almost annihilated1 much of the original surface near the coast being submerged1 and places that were formerly dry land are now covered with water to a depth of from #fjj to #ijj feet4 ,the enormous amount of material thrown into the air by the forces of the eruption is especially characteristic of this phenomenon4 ,such quantities of pumice stone and ashes fell from the clouds that1 sinking in the water and collecting on the bed of the channel1 they changed the depth of the water1 so as to render navigation dangerous4 ,indeed1 the ,sebesi ,channel1 lying on the north of the island of ,krakatoa was completely blocked by a huge bank of volcanic material1 portions of which projected above the water1 forming two smaller islands4 ,these1 however1 have since been washed away by the waves4 ,we will not attempt to give at present any explanations as to the causes of this great volcanic eruption1 since the different theories as to the cause of volcanoes will be better understood when other volcanic eruptions have been described4 ,it is sufficient here to say that if a large quantity of water should have suddenly reached a great mass of molten rock1 frightful explosive eruptions would have occurred1 and if the island was resting on a submerged crater its sudden disappearance may be explained4 ,another great wonder connected with the explosive eruption of ,krakatoa was the enormous heights to which the fine dust was thrown up into the air4 ,it has been asserted that during the most intense of these eruptions the particles reached elevations of perhaps more than twenty-five miles above the level of the sea4 ,carried by the winds1 the fine particles remained suspended in the air for many months1 and gave rise to magnificent sunlight effects1 such as early dawn1 lengthened twilights1 lurid skies1 and gorgeous sunsets of a reddish tint4 ,there were also caused curious haloes1 as well as green and blue moons4 ,the fine dust particles consisted of minute crystals of feldspar and other minerals1 and when examined under the microscope presented the appearance shown in ,fig4 #d4 ,these mineral substances permitted a portion of the light to pass through them1 thus producing wonderful optical effects in the atmosphere either because they acted like minute prisms and so produced rainbow colors1 or because they turned the rays of light out of their course as to produce what is called interference by color effects of a nature similar to the colors seen in mother-of-pearl1 rainbow coal1 or in the wing cases of many beetles4 ,the explanations of these phenomena are too difficult for a book of this character4 ,an explosive volcanic eruption is a very terrifying and wonderful phenomenon4 ,frightful roaring sounds are suddenly heard1 the earth shakes for many miles around1 when suddenly a vast quantity of molten rock1 and sometimes huge stones1 are thrown out of the crater high up into the air4 ,so great is the force that throws these materials out of the opening that heavy masses of rocks often are ejected very much faster than the projectiles from the largest guns that are used in any of the navies of the world4 ,illustration3 ,,fig4 #d4 ,,volcanic ,,dust ,,as ,,it ,,appears ,,under ,,the ,,microscope ,as the molten lava cools and falls in the form of prodigious clouds of ashes1 cinders and dust1 for many miles around the volcano1 even the light of the sun is obscured1 and one cannot see the hand before the face4 ,some of the materials in these clouds are so light that they remain suspended in the air for many hours1 often indeed for many days1 and sometimes even for years4 ,the heavier particles1 however1 soon begin to fall1 and before long the earth's surface both around the volcano1 and often at considerable distances from it1 is covered with a thick layer of ashes4 ,the sounds accompanying a volcanic eruption are often terrifying4 ,amid shakings and tremblings of the earth's crust1 known as earthquakes1 there are occasionally heard noises like the explosion of huge guns4 ,sometimes these sounds follow one another so rapidly that they produce an almost continuous roar4 ,through the roar of the explosion a curious crackling noise can be heard1 due to the fragments of stone hurled out of the crater striking against one another1 especially as the stones which are thrown out of the crater and have commenced to fall back again to the earth1 are struck by others that are still rising4 ,immense quantities of ashes1 stones1 vapor and gases are thrown upwards for great distances into the air1 while1 at the same time1 a lava stream pours over the lowest side of the crater4 ,as the column of ashes and cinders reaches its greatest height in the air1 it begins to spread outward on all sides1 rapidly growing like a huge dark mushroom4 ,this soon shuts out the light of the sun1 and from it showers of red hot ashes and cinders fall to the earth4 ,it would be extremely dangerous to be on the side of the volcanic mountain during an explosive eruption2 for1 even should you escape falling into an opening in the side of the mountain1 you might be killed by the huge stones that are constantly falling on all sides around the opening1 or might be buried under the vast showers of red hot ashes that are poured down from the dense clouds overhanging the mountain1 or suffocated by clouds of sulphur vapor that rush down its sides4 ,when at a safe distance the sight is certainly magnificent4 ,there is no light from the sun4 ,all would be in pitch darkness but for the reddish glare thrown upwards by the red hot lava1 by the glowing showers of ashes that are being rained down on the sides of the mountain1 or by terrific lightning flashes1 due to the discharge of the immense quantities of electricity produced by the forces of the eruption4 ,naturally a great volcanic eruption can cause a considerable loss of life and property4 ,when a large lava stream begins to flow down the sides of the mountain1 it cannot be stopped1 and should it flow toward a village or town it is likely to destroy the town completely4 ,besides this1 the vegetation of the country for many miles around is destroyed by the showers of red hot ashes that fall from the sky4 ,the houses of neighboring cities are similarly ruined by the great conflagrations thus set up4 ,further destruction is also caused by large streams of mud that rush down the slopes of the mountain1 or by huge waves set up in the ocean4 ,if the volcano is situated1 as most volcanoes are1 near the coast1 the showers of ashes and falling stones may set fire to vessels in the neighborhood1 or the progress of such vessels may be seriously retarded by layers of ashes or pumice stone that float on the surface4 ,sometimes these layers are so thick as actually to bring ships to a complete standstill4 ,it must not be supposed that volcanoes are in a constant state of eruption4 ,on the contrary1 nearly all volcanoes1 after an eruption1 become quiet or inactive4 ,the air soon clears by the ashes settling1 and the sunlight again appears4 ,a crust forms over the surface of the lava1 which rapidly becomes hard enough to permit one to walk over it safely4 ,the vegetation1 which has been destroyed by the hot ashes1 again springs up1 and1 if the volcano happens to be situated within the tropics1 where there is an abundance of moisture1 the land soon again becomes covered by a luxuriant vegetation4 ,most of the people1 who have escaped sudden death during the eruption1 return to the ruins of their houses2 for it is a curious fact that no matter how great has been a volcanic eruption1 or how far-reaching the ruin1 the survivors1 as a rule1 do not appear to hesitate to return to their old neighborhood4 ,in a few years the fields are re-cultivated1 the villages are rebuilt1 and the people apparently forget they are living over a slumbering volcano1 which may at any time again burst forth in a dangerous eruption4 ,a volcano that throws out molten rock1 vapor and gases is known as an active volcano4 ,an active volcano1 however1 is only correctly said to be in a state of eruption when the quantity of the molten rock1 lava or vapor it throws out is greatly in excess of the ordinary amount4 ,sometimes the volcanic activity so greatly decreases that the molten rock or lava no longer rises in the crater1 but1 on the contrary1 begins to sink1 so that the top of the lava in the crater is often at a considerable distance below its edges4 ,the lava then begins to harden on the surface1 and1 if the time is sufficient1 the hardened part extends for a considerable distance downward4 ,in this way the opening connecting the crater with the molten lava below becomes gradually closed1 the volcano being thus shut up1 or corked1 just as a bottle is tightly closed by means of a cork driven into the opening at its top so as to prevent the escape of the liquid it contains4 ,it may sound queer to say that a volcano has its crater so corked up as to prevent the escape of the lava1 but the idea is nevertheless correct and helpful4 ,to realize the size of these huge volcanic corks one must remember that the craters of some volcanoes are several miles across4 ,a volcano thus choked or corked up is said to be extinct4 ,when we speak of an extinct volcano we do not mean that the volcano will never again become active4 ,a volcano does not cease to erupt because there are no more molten materials in the earth to escape1 but simply because its cork or crust of hardened lava has been driven in so tightly that the chances of its ever being loosened again seem to be very small4 ,but small as the chances may seem we must not forget that the volcano may at any time become active1 or go into its old business of throwing out materials through its crater4 ,a volcano in an extinct condition is not unlike a steam boiler1 the safety valve of which has been firmly fixed in place4 ,if the steam continues to be generated in the boiler1 it is only a matter of time when the boiler will blow up1 and the explosion will be all the greater because the safety valve did not allow the steam to escape earlier4 ,sometimes an intermediate class of volcanoes called dormant is introduced between active volcanoes on the one hand and extinct volcanoes on the other4 ,the name dormant volcano1 or1 as the word means1 sleeping volcano1 is objectionable1 since it might lead one to think that an extinct volcano is not sleeping but dead1 and this is wrong4 ,since the plug of hardened lava in the volcanic crater is generally at a much lower level than the top of the crater1 the crater will soon become filled to a greater or less depth with water1 produced either by the rain1 or by the melting of the snow that falls on the top of the mountain4 ,crater lakes1 often of very great depths1 are common in extinct volcanoes4 ,of course1 when an extinct volcano again becomes active1 two things must happen if the eruption is explosive4 ,in the first place1 the force of the explosion must be sufficiently great to loosen the stopper or plug of hardened lava which stops it4 ,in doing this the mass is broken into a number of fragments that are thrown forcibly upwards into the air4 ,after rising often for great heights they soon fall again on the sides of the mountain4 ,but besides the breaking up of the stopper1 the lake in the crater of the volcano is thrown out along with the cinders or ashes1 producing very destructive flows of what are called aqueous lava or mud streams4 ,these streams flow down the sides of the mountain1 carrying with them immense quantities of both the ashes thrown out during the eruption1 or those that have collected around the sides of the crater during previous eruptions4 ,very frequently1 these streams of aqueous lava produce greater destruction than the molten lava4 ,if you have ever watched common ants at work clearing out or enlarging their underground homes1 in a piece of smooth gravel walk in your garden1 you can form some idea why the mountain immediately around a volcanic crater is conical in shape4 ,if the colony of ants happens to be fairly large1 you can see an almost unbroken stream of these industrious little animals1 each bearing in its mandibles a small grain of sand or gravel brought up from some place below the surface4 ,carrying it a short distance from the opening1 it throws it on the ground1 rapidly returning for another load4 ,in this way there is heaped up around all sides of the opening a pile of sand or gravel1 the outward slopes of which gives the pile a conical form4 ,you have1 probably1 noticed that the steepness of the slopes depends on the size of the grains2 for the larger these grains the sharper or steeper the slopes1 the very fine grains producing flat mounds or cones4 ,it is the same with a volcanic cone4 ,the materials that are thrown upwards into the air1 falling again on the mountain1 collect around the crater on all sides1 thus giving it the characteristic cone-like shape of the volcanic mountain4 ,where nothing occurs to disturb the formation of the cone its height above the level of the sea will gradually increase4 ,very frequently1 however1 during explosive eruptions1 a large part of this cone will be blown away by the force of the eruption only to be again built up during some later eruption4 ,indeed1 in the case of volcanic islands1 the force of a great volcanic eruption is sometimes so great that not only is a large volcanic mountain blown entirely away1 but a hole is left1 where it had been standing1 that extends further downwards below the level of the sea than the top of the mountain extended previously above it4 ,the above are some1 but by no means all1 the wonders attending volcanic eruptions4 ,we shall refer to others in subsequent chapters in describing particular eruptions4 ,,chapter ,,iii ,,the ,,volcanic ,,island ,,of ,,hawaii ,the volcanic island of ,hawaii1 the largest of the ,sandwich ,island chain1 is situated in the mid ,pacific1 south of the ,tropic of ,cancer4 ,as shown in ,fig4 #e1 this island chain consists of ,hawaii1 ,maui1 ,molokai1 ,oahu1 ,kauai1 ,nihau1 and about eight large islands1 together with numerous small islands1 extending in a general northwest direction from ,hawaii to ,nihau1 a distance of about #djj miles4 ,like most volcanic islands they lie in more or less straight lines1 probably along fissures1 in this case in two nearly parallel lines4 ,the island of ,nihau1 however1 is an exception1 the direction of the greatest length being almost straight across the two parallel lines4 ,the ,sandwich ,islands lie #b1jjj miles from ,san ,francisco in deep water1 between #b1jjj and #c1jjj fathoms1 or between #ab1jjj and #ah1jjj feet in depth4 ,this island chain consists of great volcanic mountains1 that had1 at one time1 fifteen active volcanoes of the first class4 ,these are now all extinct but three1 and all of these are on the island of ,hawaii4 ,in his report to the ,united ,states ,geological ,survey for #ahhb-hc1 ,dutton states that the summit of ,mt4 ,haleakala on ,east ,maui is #aj1cej feet above the sea level4 ,oahu has peaks on its eastern side #b1ijj feet high1 and peaks on the western side #c1hej feet high4 ,the summit of ,kauai is probably #f1bjj feet above the sea4 ,illustration3 ,,fig4 #e4 ,,the ,,hawaiian ,,islands ,from ,u4 ,s4 ,geological ,survey ,it can be shown by deep-sea soundings that all these volcanic piles are the summits of a gigantic mountain mass that rises abruptly from the bed of the ,pacific4 ,there are reasons for believing that this submarine chain continues for many hundreds of miles in the same direction beyond ,kauai4 ,the extinct volcano1 ,haleakala1 on ,east ,maui appears to have been in eruption at a much later day than ,mt4 ,kea1 which is also an extinct volcano4 ,but the natives have no traditions of any eruptions4 ,the volcanoes on the other islands have been extinct for a very long time judging from the extent of their erosion4 ,dutton is of the opinion that the western islands of the chain have been extinct for much longer times than the remaining islands4 ,the ,sandwich ,islands1 also known as the ,hawaiian ,islands1 are one of the colonial possessions of the ,united ,states4 ,the island of ,hawaii is about #b1jjj miles from ,san ,francisco4 ,honolulu1 on the island of ,oahu1 the principal seaport of the chain1 has a pleasant climate1 and is an important coaling station for warships1 commercial vessels1 whalers1 and trading ships generally4 ,the principal product of the island is sugar cane4 ,the island of ,hawaii1 as shown in map1 ,fig4 #f1 consists of five volcanic mountains and some small coral reefs4 ,these mountains are3 ,mt4 ,kea1 on the north1 #ac1hje feet in height2 ,mt4 ,haulalai1 in the west central part of the island1 #h1bgc feet in height2 ,mt4 ,loa1 in the south central part of the island1 #ac1fge feet in height2 ,mt4 ,kilauea1 twenty miles east of the crater of ,loa1 #d1jdj feet high at the ,volcano ,house1 and #d1aeh feet on the highest point on the west1 and ,kohala1 #e1eje feet in height1 running through the northwestern part of the island1 and the ,kohala mountains in the northwestern part4 ,illustration3 ,,fig4 #f4 ,,hawaii ,from ,dana's ,manual of ,geology ,of these mountains1 ,mt4 ,loa and ,kilauea are the only active volcanoes1 and are in frequent eruption4 ,mt4 ,haulalai was in eruption during #ahjd4 ,mt4 ,kea has not been active during historical times1 while ,mt4 ,kohala has been inactive for so long a time that its slopes are deeply gullied wherever the rivers flow down them4 ,as you can see from the map1 ,hawaii is very large4 ,it has a length of ninety-three miles from north to south1 and a breadth of eighty miles from east to west1 its area is about #f1ejj square miles4 ,with the exception of small patches of coral reefs1 ,hawaii is formed entirely of lava1 and is the largest pile of lava in the world with the single exception of ,iceland4 ,where the islands of the ,hawaiian chain have coral reefs extending off their coasts1 excellent harbors are found in the deep waters between the islands and the reefs4 ,hawaii1 however1 has no extended reefs of this character1 and1 consequently1 no first-class harbors4 ,hilo1 on the eastern coast1 is the best harbor1 and is1 therefore1 the principal settlement4 ,a very brief examination of the map of ,hawaii will show you that there are no rivers on the island1 except on the sides exposed to the wind1 that is1 on the northern and northeastern slopes4 ,since the yearly rainfall on ,hawaii is large1 being in the neighborhood of a hundred inches1 you will understand that considerable rain water falls on the island4 ,in those parts of the island where it does not run off the surface it must drain downward through the loose piles of broken rocks or cinders4 ,a rainfall of one hundred inches a year means that if all the rain which falls on each square foot of surface was collected in a flat vessel one foot square with vertical sides it would fill the vessel to the depth of one hundred inches1 or over eight feet4 ,the drainage of the rainwater downwards through these parts of the island1 must1 therefore1 be large4 ,another curious fact you can notice on the map1 is that the lava streams of the past fifty years from ,mt4 ,loa indicated by heavy dotted lines1 in no cases begin at the crater1 but start at fairly considerable distances from it4 ,later on in this chapter we shall explain the reason for this curious fact4 ,since practically the whole of ,hawaii has been formed from the streams of lava that have flowed at one time or another1 you can understand how great these flows must have been4 ,but to do this fully you must not only take into consideration the portions of the island that lie above the ocean and reach into the air at its greatest height to #ac1hje feet above its surface1 you must also remember that this mountain rises from a deep ocean1 so that if all the water were removed1 you would see ,hawaii towering up above the former level of the sea to the height of about #ca1jjj feet1 or higher than ,mt4 ,everest1 the highest point on the earth above the present sea level4 ,this would be1 approximately1 five and eight-tenths miles4 ,you can understand1 therefore1 how great the flow of lava must have been4 ,we shall begin the description of ,hawaii with the active volcano of ,mt4 ,loa1 or1 as it is sometimes called in ,hawaii1 ,the ,white ,mountain4 ,you will remember that the eruption of ,krakatoa was of the explosive type4 ,practically no melted rock or lava escaped from the crater4 ,indeed1 if it had escaped it would not have been seen2 for1 not only the cone near the crater1 but also much of the mountain itself was blown completely out of sight and covered by the waters of the ocean4 ,the eruptions of ,mt4 ,loa are of an entirely different type4 ,in ,loa there are no explosions1 the eruptions being what are called the non-explosive or quiet volcanic eruption type4 ,it will be necessary to explain some of the peculiarities of this kind of eruptions4 ,there is a great difference in the liquidity or the ease with which different kinds of lava flow4 ,some lava is very thick or viscid1 or is sticky like thick molasses or tar1 and therefore flows very sluggishly4 ,other lava is thin or mobile1 more closely resembling water in the ease with which it flows4 ,now1 in the case of a volcanic mountain of fairly considerable height1 where the lava possesses marked liquidity1 the lava as it rises from great depths in the tube of the volcano seldom flows over the top or rim of the crater4 ,this is not because the force that brings the lava up is unable to carry it a few thousand feet higher1 so that it can run over the brim of the crater1 but because the walls of the volcanic mountains are unable to stand the great pressure which the mass of liquid lava exerts against their sides4 ,it can be shown that a column of liquid lava #ejj feet high1 will exert a pressure on the walls of the crater of about #fbe pounds to the square inch4 ,therefore1 in very high volcanic mountains1 long before the lava can reach the edge of the crater and overflow1 the pressure becomes so great1 that cracks or fissures are made in the sides of the mountain1 through which the lava is quietly discharged2 when1 of course1 the level of the lava in the crater falls considerably4 ,in volcanoes of the explosive type1 no matter what may be the condition of lava1 should a large quantity of water suddenly find an entrance to a large body of molten lava at some distance below the surface1 the lava would be suddenly thrown explosively into the air1 where being chilled1 it would afterwards descend in showers of ashes1 cinders1 or volcanic dust4 ,in some volcanic mountains such as ,mt4 ,loa1 the crater1 instead of being situated at the top of a conical pass of ashes or other material1 consists of a pit-like depression1 generally occupying a level tract or plain at the top of the mountain4 ,this pit is known as a caldera1 or caldron1 or what you might1 perhaps1 call a huge kettle or boiler4 ,the pit has more or less vertical sides that extend downwards for unknown depths to the place from which the lava comes4 ,the vertical walls of the caldera are not1 however1 smooth1 but exhibit numerous horizontal ledges1 that mark places where portions of the floor of the caldera were situated at different times4 ,at the bottom of the large pit or caldera on the summit of ,mt4 ,loa can be seen the level floor formed of hardened lava4 ,this floor is surrounded by vertical walls on which can be seen the broken edges of the old lake bed4 ,captain ,dutton1 in a paper on ,hawaiian volcanoes1 prepared for the ,united ,states ,geological ,survey1 and published in its ,fourth ,annual ,report for #ahhb-hc1 thus describes the appearance at the great crater as it was in #ahhb4 ,the summit of ,mauna ,loa 7,mt4 ,loa71 is a broad and large platform about five miles in length and four miles in width1 within which is sunken the great caldera called ,mokuaweoweo4 ,the distance from the point where we first reach the summit to the brink of the pit is about a mile and a half4 ,the surface of the platform is much more rugged than the slopes just ascended4 ,it is riven with cracks1 and small faults1#b and piles of shattered rock are seen on every hand4 ,nowhere is there to be seen the semblance of a cinder cone4 ,doubtless many eruptions have broken forth from the various fissures on this summit1 but only here and there can insignificant traces of such catastrophes be definitely distinguished4 ,the absence of fragmental ejecta 7broken rock that are thrown out7 is extraordinary4 ,the shattered blocks1 slabs1 and spalls 7chips7 which everywhere cumber the surface appear to have resulted from the spontaneous shivering and shattering of the lava sheets by their own internal tensions as they cooled4 ,fig4 #g1 taken from ,dutton's report1 gives the general shape of this great caldera4 ,dutton's description of the same is as follows3 ,the length of the main caldera is a little less than three miles and its width about a mile and three-quarters4 ,its floor1 viewed from above1 appears to be composed of a series of flat surfaces occupying two distinct levels1 the higher upon the surface of the black ledge1 the lower lying within the ledge4 ,upon the western side is a small cinder cone standing close upon the border of the black ledge4 ,it is the only one visible1 either within the caldera or upon the surrounding summit4 ,its height is about #abe or #acj feet4 ,it was seen in operation1 throwing up steam1 clots of lava1 and lapilli 7some of the larger pieces of fragmentary lava7 in the year #ahgh4 ,the only other diversifications of the floor are many cracks which traverse it1 the larger of which are distinctly visible from above4 ,some of them are considerably faulted4 ,there is no difficulty in recognizing the fact that the whole floor has been produced by the sinkage of the lava beds which once continued over the entire extent of the depression1 their undersides having been melted off most probably by the fires beneath4 ,the lava beds in the immediate vicinity of the brink upon the summit platform wear the aspect of some antiquity4 ,they have become brown and carious by weathering1 and1 although no soil is generated1 little drifts of gravel are seen here and there mixed with pumice4 ,since the caldera was formed there is no indication that the lavas have anywhere overflowed its rim4 ,and yet it is a very strange fact that within a half mile1 and again within a mile to a mile and a half1 lavas have been repeatedly erupted within the last forty years from the summit platform1 and have outflowed at points situated from #gjj to #ijj feet above the level of the lava lake within4 ,traces may also be seen1 at varying distances back of the rim1 of very many eruptions in which the rocks betoken great recency1 although no dates can be assigned to their occurrence4 ,illustration3 ,,fig4 #g4 ,,panorama ,,of ,,mokuaweoweo ,from ,u4 ,s4 ,geological ,survey ,illustration3 ,,fig4 #h4 ,,view ,,of ,,the ,,crater ,,of ,,kilauea ,,from ,,the ,,volcano ,,house ,from ,u4 ,s4 ,geological ,survey ,during his visit to this great pit1 ,captain ,dutton succeeded in climbing down the almost vertical walls on the side of the crater1 and1 reaching the surface of the hardened lake1 walked over it4 ,it must have required no little courage to thus venture on the thin floor of a lake which he knew was filled to great depths with red hot boiling lava1 for he was walking over the surface of a slumbering volcano1 that might at almost any moment awaken1 and opening1 swallow him and his companions4 ,through enormous cracks in the floor1 he could feel the heat from the molten mass1 while1 through the same openings came suggestive whiffs of sulphur vapor4 ,during the eruption of this mountain1 on ,january #bc;d1 #ahei1 the light from the glowing lava streams was bright enough to read fine print at ,hilo1 a distance of thirty-five miles4 ,during the eruption of #aheb1 a stream of white-hot lava was thrown up into the air from one of the fissures to a height of from #cjj to #djj feet4 ,illustration3 ,,stones ,,and ,,lava ,,thrown ,,upwards--,,eruption ,,of ,,mokuaweoweo1 ,,hawaii1 ,,july #d-ba1 #ahii ,from a ,stereograph1 ,copyright1 by ,underwood ,underwood ,when an eruption takes place in ,mt4 ,loa the column of lava slowly rises in the crater1 threatening to overflow its lowest edges1 but before this can take place the pressure becomes so great that some portion of the mountain below the crater is fractured and the lava quietly escapes4 ,during some conditions of the mountain every fifteen or twenty minutes a column of highly glowing lava is shot upwards like a fountain to a height of #ejj feet and over1 falling back into the lake in fiery spray4 ,unusual heights of these streams are generally followed by an eruption4 ,these curious jets of molten rock certainly cannot be due to the pressure of higher columns of lava1 since the crater itself is near the top of a high plain4 ,they are believed to be due to steam formed by the penetration of the rain water that falls on this part of the mountain4 ,you can now understand why the lava streams escaping from ,mt4 ,loa as shown on the map1 in ,fig4 #f1 do not begin at the level of the crater2 for the discharge of the lava does not take place over the rim of the crater1 but through the cracks or fissures formed further down the sides of the mountains4 ,it must not be supposed1 however1 that the fissures are limited to the sides of the mountain where they can be seen4 ,they probably occur in many places below the surface of the water on some part of the bed of the ocean4 ,the crevices that are formed in this manner in the sides of the mountain vary greatly in size1 some being so narrow that the lava scarcely flows through them at all but simply fills up the crevice1 hardens on cooling1 and mends the cracks in the mountains1 in the way that a crack is mended in a piece of china by the use of glue or in a wall of masonry by mortar4 ,through the largest crevices or cracks1 however1 large lava streams may continue to flow often for several weeks1 or even longer4 ,sometimes1 especially towards the close of the eruptive flow1 the lava may escape disruptively1 so that small cones are formed along the lines of the fissures4 ,cones of this character are called lateral cones1 and in the case of a volcanic island1 where the lava flows out below the level of the water1 the lateral cones sometimes project above the water and form volcanic islands or dangerous shoals that impede navigation4 ,when the lava pours out of a crevice in the side of the mountain1 a river of molten rock rushes down the slopes1 at first like a torrent1 but on reaching the more nearly level ground1 it spreads out in great lava lakes or fields1 the surface of which takes on the characteristic black appearance of basalt1 a certain kind of glass1 for the lavas of ,mt4 ,loa are generally basaltic4 ,after an eruption the hardened floor of lava in the caldera1 being no longer supported by the liquid mass formerly below it1 falls in1 leaving a large cavity with only the edges of the old floor clinging to the sides of the pit4 ,it will be interesting to give a short account of some of the great lava streams that have been poured out at different times from ,mt4 ,loa4 ,in the great eruption of ,august #aath1 #ahee1 the lava escaped through fissures from two to thirty inches in width4 ,then1 flowing in a continuous stream1 it did not stop until it was within five miles of ,hilo4 ,in the eruption of ,january #bc;d1 #ahei1 the lava stream flowed towards the northwest on the east side of ,haulalai1 reaching the sea in eight days4 ,the eruption of ,march #bgth1 #ahfh1 was characterized by severe earthquake shocks1 one of which1 occurring on the second of ,april1 destroyed many houses and produced huge fissures in the earth4 ,these shocks produced great earthquake waves that reached distant coasts4 ,mt4 ,kilauea1 lies at a lower level towards the east4 ,this crater is situated at #d1jdj feet above the level of the sea1 and is nearly #f1jjj feet below the caldera on the top of ,mt4 ,loa4 ,fig4 #h1 taken from the ,united ,states ,geological ,survey1 ,fourth ,annual ,report1 for #ahhb-hc1 shows a view of ,kilauea from the ,volcano ,house4 ,dutton gives the following description of the appearance of ,halemaumau1 the pit crater or caldera of ,kilauea4 ,in front of us and right beneath our feet1 over the crest of a nearly vertical wall1 more than #gjj feet below1 is outspread the broad floor of the far-famed ,kilauea4 ,it is a pit about three and a half miles in length1 and two and a half miles in width1 nearly elliptical in plan and surrounded with cliffs1 for the most part inaccessible to human foot1 and varying in altitude from a little more than #cjj feet to a little more than #gjj feet4 ,the altitude of the point on which we stand is about #d1bjj feet above the sea4444 ,the object upon which the attention is instantly fixed is a large chaotic pile of rocks1 situated in the centre of the amphitheatre1 rising to a height which by an eye estimate appears to be about #cej to #djj feet4 ,from innumerable places in its mass volumes of steam are poured forth and borne away to the leeward by the trade wind4 ,the color of the pile is intensely black4444 ,around it spreads out the slightly undulated floor of the amphitheatre1 as black as midnight4 ,to the left of the steaming pile is an opening in the floor of the crater1 within which we behold the ruddy gleams of boiling lava4 ,from numerous points in the surrounding floor clouds of steam issue forth and melt away in the steady flow of the wind4 ,the vapors issue most copiously from an area situated to the right of the central pile1 and in the southern portion of the amphitheatre4 ,desolation and horror reign supreme4 ,the engirdling walls everywhere hedge it in4 ,but upon their summits1 and upon the receiving platform beyond1 are all the wealth and luxuriance of tropical vegetation heightening the contrast of the desolation below4444 ,illustration3 ,,fig4 #i4 ,,crater ,,of ,,kilauea ,from ,dana's ,manual of ,geology ,fig4 #i represents the pit-like crater of ,kilauea as it appeared after the eruption of #ahhf4 ,here1 as will be seen1 there are several lakes of lava1 the largest of which is known as ,halemaumau4 ,the eruption of #ahhf1 like all the eruptions of ,kilauea1 consisted of the escape of the lava from an opening on the side of the mountain below the crater1 and a sinking in of the hardened floor of the crater4 ,the figure also shows the position of the ,new ,lake that lies east of ,halemaumau4 ,the extent and appearance of each of these lakes are constantly changing1 both as to height and area4 ,dutton gives the following description of the appearance of the lake of lava1 and some curious phenomena that occur on its surface4 ,he is describing the general appearance of the pool of molten lava covered as it is with a hardened black crust3 ,the surface of the lake is covered over with a black solidified crust showing a rim of fire all around its edge4 ,at numerous points at the edge of the crust jets of fire are seen spouting upwards1 throwing up a spray of glowing lava drops1 and emitting a dull1 simmering sound4 ,the heat for the time being is not intense4 ,now and then a fountain breaks out in the middle of the lake and boils freely for a few minutes4 ,it then becomes quiet1 but only to renew the operation at some other point4 ,gradually the spurting and fretting at the edges augment4 ,a belch of lava is thrown up here and there to the height of five or six feet1 and falls back upon the crust4 ,presently1 near the edge1 a cake of the crust cracks off1 and one edge of it bending downwards descends beneath the lava1 and the whole cake disappears1 disclosing a naked surface of liquid fire4 ,again it coats over and turns black4 ,this operation is repeated edgewise at some other part of the lake4 ,suddenly a network of cracks shoots through the entire crust4 ,piece after piece of it turns its edge downwards and sinks with a grand commotion1 leaving the whole pool a single expanse of liquid lava4 ,the lake surges feebly for awhile1 but soon comes to rest4 ,the heat is now insupportable1 and for a time it is necessary to withdraw from the immediate brink4 ,it is very curious to think of cakes of hardened lava floating on the surface of molten lava1 but1 of course1 this is just as natural as cakes of ice floating on the surface of water2 for a cake of hardened lava is1 as you will understand1 only a cake of frozen lava1 and1 being lighter than the molten lava1 must1 of course1 float on its surface4 ,the disappearance of these cakes of frozen lava and their remelting is still more curious1 and can be explained as follows3 ,the frozen or solidified mass of black basalt is a trifle lighter than the lava on which it is floating only while its temperature is high1 and therefore expanded by heat4 ,as soon as it cools1 its density increases1 and when it becomes a little greater than that of the liquid lava1 it begins to sink and soon disappears4 ,illustration3 ,,fig4 #aj4 ,,sections ,,of ,,kilauea ,,at ,,different ,,periods ,from ,dana's ,manual of ,geology ,professor ,dana1 who has made a careful study of the phenomena of ,kilauea1 shows in ,fig4 #aj1 a cross section of ,kilauea at different times4 ,before the eruption of #ahbc1 the depth of the crater was from #hjj to #a1jjj feet4 ,at the eruption the bottom #fjj to #hjj feet1 making the depth of ,kilauea over this deeper central part about #a1ejj feet4 ,the varying depths at different dates are clearly marked on the drawing4 ,the eruptions of ,kilauea generally occur as follows3 ,first there is a slow rising of the lava in the crater4 ,this rising continues until the pressure is so great that the mountain is ruptured at some lower place4 ,next a discharge of the lava and a sinking to a level in the conduit that will depend on the position of the crevice4 ,then a gradual falling in of the hardened floor of the lake1 a portion of the horizontal walls remaining on the sides of the caldera4 ,the eruption of ,kilauea1 however1 has not always been of the quiet type4 ,there was an eruption in the year #aghi that would appear to have been of the explosive variety4 ,the following account is given by ,dana as taken from a history of the ,sandwich ,islands by the ,rev4 ,i4 ,dibble1 published in #ahdc3 ,the army of ,keoua1 a ,hawaiian chief1 being pursued by ,kamehamoha1 were at the time near ,kilauea4 ,for two preceding nights there had been eruptions1 with ejections of stones and cinders4 ,the army of ,keoua set out on their way in three different companies4 ,the company in advance had not proceeded far before the ground began to shake and rock beneath their feet1 and it became quite impossible to stand4 ,soon a dense cloud of darkness was seen to rise out of the crater1 and1 almost at the same instant1 the thunder began to roar in the heavens and the lightning to flash4 ,it continued to ascend and spread around until the whole region was enveloped1 and the light of day was entirely excluded4 ,the darkness was the more terrific1 being made visible by an awful glare from streams of red and blue light1 variously combined through the action of the fires of the pit and the flashes of lightning above4 ,soon followed an immense volume of sand and cinders1 which were thrown to a great height1 and came down in a destructive shower for many miles around4 ,a few of the forward company were burned to death by the sand1 and all of them experienced a suffocating sensation4 ,the rear company1 which was nearest the volcano at the time1 suffered little injury1 and after the earthquake and shower of sand had passed over1 hastened on to greet their comrades ahead on their escape from so imminent a peril4 ,but what was their surprise and consternation to find the centre company a collection of corpses6 ,some were lying down1 and others were sitting upright1 clasping with dying grasp their wives and children1 and joining noses 7the mode of expressing affection7 as in the act of taking leave4 ,so much like life they looked that at first they supposed them merely at rest1 and it was not until they had come up to them and handled them that they could detect their mistake4 ,mr4 ,dibble adds3 ,a blast of sulphurous gas1 a shower of heated embers1 or a volume of heated steam would sufficiently account for this sudden death4 ,some of the narrators who saw the corpses1 affirm that though in no place deeply burnt1 yet they were thoroughly scorched4 ,as you will see in ,chapter ,,xi1 this sudden and awful death due to highly heated air and dust particles1 caused even a greater loss of life in the catastrophic eruption of ,pele1 in ,martinique on ,may #h1 #aijb4 ,by reason of its situation at a lower level on the slopes of ,mt4 ,loa1 ,kilauea was at one time thought to be one of the craters lower down on the slopes of ,loa4 ,this was the opinion of ,professor ,dana when he examined the district in #ahdj4 ,since this time the region has been more carefully studied1 and ,mt4 ,loa and ,kilauea1 are now generally regarded as separate and independent volcanoes1 neither of which acts as a safety valve for the other4 ,we shall not attempt in this chapter to say anything concerning the sources or places from where these great supplies of lava have been drawn4 ,this will be left to some subsequent chapter1 after we have described still other volcanoes4 ,the outlines of mountains like ,mt4 ,loa or ,kilauea differ greatly from mountains like ,vesuvius2 their slopes1 like the slopes of all other ,hawaii volcanoes1 have an inclination which does not exceed #aj4 ,the lava streams1 therefore1 as they flow down the mountains1 move more slowly than they would were the slopes more precipitous1 as in mountains like ,vesuvius4 ,there have been many eruptions of ,kilauea4 ,that which occurred in the year #ahdj1 was of great magnitude 7see map1 ,fig4 #f71 and began in a fissure southwest of the crater4 ,the principal eruption1 however1 broke out about twelve miles from the sea coast1 and about twenty-five miles east of ,kilauea4 ,here an enormous mass of lava forming a stream nearly three miles wide reached the ocean at ,nanawale4 ,when an eruption takes place on ,mt4 ,loa through a fissure at the height of #aj1jjj to #ac1jjj feet the length of the lava streams is frequently as great as twenty-five to thirty miles4 ,often the lava though hardening at the surface will continue to flow underneath through huge tunnels1 of which the top and sides are composed of solidified parts of the same lava stream4 ,after the flow has ceased long hollow tunnels often remain4 ,if the lower end of such a tunnel containing molten lava is momentarily closed1 the pressure of the lava above may not only burst through the obstruction1 but may even throw the lava upwards in jets #cjj to #gjj feet high4 ,probably most of you have seen illumined fountains where jets of water are beautifully lighted up by different colored electric lights placed below them4 ,such fountains1 however1 can but poorly compare either in beauty or grandeur with these wonderful lava fountains1 common on the slopes of ,mt4 ,loa during an eruption4 ,,chapter ,,iv ,,the ,,volcanic ,,island ,,of ,,iceland ,the island of ,iceland consists of a number of volcanic mountains some of which are still active4 ,as can be seen from the map1 shown in ,fig4 #aa1 ,iceland lies in the ,north ,atlantic ,ocean1 immediately below the ,arctic ,circle1 about #bej miles east of ,greenland1 and #fjj miles west of ,norway4 ,its length from east to west is about #cjj miles1 and its breadth about #bjj miles1 its total area1 including the adjacent islands1 being more than #dj1jjj square miles4 ,were all the water removed from the ,north ,atlantic ,ocean1 it would be seen that ,iceland rests on the bed of the ,atlantic1 on a submarine plateau or highland2 for1 in this part of the ocean the water is only from #a1ejj to #c1jjj feet deep4 ,this submarine plateau extends as far as ,norway on the east1 ,greenland on the north1 and the island of ,jan ,mayen on the northeast4 ,immediately north of the plateau the ocean suddenly drops to a depth of #ab1jjj to #ae1jjj feet4 ,illustration3 ,,fig4 #aa4 ,,iceland ,toward the south the plateau extends with but few interruptions through the middle of the ocean to a shoal known as the ,dolphin ,shoal1 as far as lat4 #be ,n4 ,this part of the ocean1 which can only relatively be called a shoal1 is not generally deeper than #i1fjj feet1 although in some places the water is more than #ab1jjj feet deep4 ,on each side of the ,dolphin ,shoal the water is much deeper1 being in places #ae1jjj feet on the east1 while on the west there are depths as great as from #ag1jjj to #ba1jjj feet4 ,this sunken plateau1 possibly including the shallower plateau on the north1 is believed by some to be the remains of the fabled continent of ,atlantis1 to which we shall refer in another part of this book4 ,the coast line of ,iceland is unbroken on the southeast1 but the remainder of the coast is deeply indented with bays or fiords in which are many excellent harbors4 ,iceland is liable to frequent earthquake shocks and volcanic eruptions4 ,from careful records that have been preserved in the history of the island1 we learn that since the beginning of the twelfth century there have practically never been intervals longer than forty years1 and more generally not longer than twenty years1 in which there has not been a great earthquake or a great volcanic eruption4 ,these volcanic eruptions are often very protracted4 ,for example1 one eruption of the volcano ,hecla continued for six years without ceasing4 ,sir ,charles ,lyell1 the great ,english geologist1 writes as follows about ,iceland3 ,earthquakes have often shaken the whole island at once1 causing great changes in the interior1 such as the sinking down of hills1 the rending of mountains1 the desertion of rivers by their channels1 and the appearance of new lakes4 ,new islands have often been thrown up near the coast1 some of which still exist1 while others have disappeared1 either by subsidences or the action of the waves4 ,in the interval between eruptions innumerable hot springs afford vent to the subterranean heat1 and solfataras discharge copious streams of inflammable matter4 ,the volcanoes in different parts of the island are observed1 like those of the ,phlegran ,fields1 ,italy1 to be in activity by turns1 one vent often serving for a time as a safety valve for the rest4 ,many cones are often thrown up in one eruption and in this case they take a linear direction1 running generally from southeast to northwest4 ,the volcanic eruptions of ,iceland belong for the greater part to the fissure type4 ,during a volcanic eruption in ,iceland the ground is split in fissures or cracks1 generally parallel to each other1 and varying in width from a few inches to several yards4 ,these fissures extend for great distances across the country4 ,the lava quietly wells out along the fissures not unlike the way quiet spring waters flow from their reservoirs4 ,according to ,dr4 ,th4 ,thoroddsen1 the ,icelandic geologist1 there are two systems of fissures extending through ,iceland1 from southwest to northeast in the southern part of the island1 and from north to south in the northern part4 ,where two lines of fissures cross each other the points of intersection may be especially active4 ,dr4 ,th4 ,thoroddsen arranges the volcanoes of ,iceland under three heads1 i4 e41 cone-shaped volcanoes2 lava cones2 and chains of craters1 the last being the commonest4 ,out of #ajg volcanoes examined by him in ,iceland1 eight were of the ,vesuvian type1 or were built up of layers of lava and volcanic ashes2 sixteen were of the lava-cone type1 similar to ,mt4 ,loa1 of the ,hawaiian ,islands1 and the remaining eighty-three were of the type of crater chains4 ,the volcano of ,snaefell ,jkul1 #d1gaj feet above the level of the ocean1 is built up of alternate layers of lava and hardened volcanic mud4 ,it is not1 however1 a true cone-shaped mountain4 ,the largest volcano in ,iceland1 the ,dyngjufkll1 with its immense crater of ,askja1 has an area of some twenty-five square miles4 ,in its form it resembles ,snaefell4 ,volcanoes of the lava-cone type have been built up entirely of lava and have a slight angle of inclination4 ,these volcanoes range in size from small hillocks to the largest mountains on the island4 ,their cones generally stand on a base of wide circumference and frequently rise to great heights1 the top being occupied by a caldera1 or pit crater like that on ,mt4 ,loa or ,kilauea4 ,volcanoes of the type of chain-craters follow the natural fissures in the crust4 ,these craters are generally low1 seldom being more than #cej feet high4 ,there are also seen in ,iceland caldron-shaped depressions that have been formed by explosive eruptions4 ,one of the best instances of such craters is ,viti1 on the side of ,mt4 ,krafla4 ,this crater was formed by the sudden eruption of ,may #agth1 #agbd4 ,the lava sometimes quietly runs out of the entire length of the fissure without forming any cone4 ,this was the case of a great fissure known as the ,eldgja ,chasm4 ,here three lava streams covered an area of #bgj square miles4 ,as the lava comes out of the fissures1 it generally produces long ramparts of slags1 and blocks of lava that are piled up on either side of the fissure4 ,sometimes a line of low cones is built up4 ,these cones consist of heaps of slag1 cinders1 and blocks of lava4 ,their craters are not rounded as in the case of volcanoes of the ,vesuvian type1 but are oblong1 or have their greatest diameter extending in a direction of the fissure4 ,icelandic lava as it escapes from the fissures is peculiar in that it is very viscid or plastic and can be readily drawn out into long threads that can be spun into ropes4 ,when such lava runs down the sides of a steep slope1 it often splits on cooling into separate blocks4 ,where it runs over flat1 level ground1 however1 it spreads uniformly on all sides1 producing vast level lava deserts that are as flat as the surface of a well built floor4 ,there are many rivers in the north and the west of ,iceland4 ,now1 as the lava streams flow out of the fissures they enter the channels of the rivers so that the streams of water must find new paths to the sea1 and this operation may be repeated again and again4 ,often the time between eruptions is long enough to give the rivers opportunity to cut deep channels or gorges in their new channels2 but on the next escape of the lava these gorges and valleys are again filled with the molten rock1 and the rivers must begin their channel cutting all over4 ,you will note the frequent use of the word ,jkul1 as ,snaefell ,jkul1 ,skaptar ,jkul1 ,orefa ,jkul1 etc4 ,the name ,jkul means a large mass of ice1 or a mountain that is continually covered with snow1 for example1 ,snaefell ,jkul1 is a beautifully shaped1 snow-covered mountain situated on a point of land on the western coast of the island1 extending out nearly fifty miles into the sea1 between the ,faxa ,fiord and the ,briela ,fiord4 ,it is a very conspicuous object1 being visible to passing ships at considerable distances from the island4 ,orefa ,jkul is the highest mountain in ,iceland4 ,skaptar ,jkul is one of the active volcanoes of ,iceland4 ,there can be no doubt that ,iceland has been formed entirely by lava thrown up from the bottom of a submarine plateau1 until it extended above the surface of the waters4 ,to make an island entirely of lava with an area of #dj1jjj square miles1 must1 of course1 have required many cones or craters that continued to pour forth lava for periods of time much longer than those during which man has lived on the earth4 ,the surface of ,iceland is far from attractive4 ,the interior is practically a vast lava desert1 covered with snow-clad mountains or ,jkuls4 ,there is no plant life except in marshy lands near the coasts1 and even here scarcely enough grass is raised to feed the few cattle and horses owned by the inhabitants4 ,there is no agriculture1 owing to the very short summers1 so that all grain is brought from ,europe4 ,every now and then the grass crop is destroyed by accumulation of ,polar ice on the northern and western coasts4 ,such failures are always attended by great famines1 when many of the people die4 ,should you ever visit ,iceland you would probably be surprised to hear the people speaking about their forests4 ,you might go over all the coasts of the island without seeing anything larger than a birch bush1 not much higher than six feet4 ,these are what the ,icelanders like to speak of as their forest trees1 and ,i suppose there is no harm done1 if one only understands just what they mean by trees4 ,while1 however1 ,iceland has practically no trees1 yet it has no difficulty in obtaining a plentiful supply of timber1 since in the deep fiords or bays on the western and southern coasts there can always be found much drift timber brought there by the ocean currents from the forests of ,america4 ,the principal town or settlement in ,iceland is ,reykjavik1 the capital of the island1 on the southwestern coast2 this is the chief trading place on the island4 ,thingvalla is also an important town4 ,the lavas that form the entire mass of ,iceland were thrown out both before and since the glacial age4 ,it is the opinion of ,geikie that these outflows have continued uninterruptedly since that age to the present time4 ,it is known that the lavas of ,iceland were thrown out both before and after the glacial age1 because during the glacial age1 deep cuttings or groovings were made on the surface of the earth by the glaciers as they slowly moved over it4 ,now lava beds containing the glacial scratches have been found and resting on them are other lava streams4 ,the scratched lavas must1 therefore1 have been thrown out before the glacial age1 and the second lavas after that age4 ,let us now examine some of the more active volcanoes of ,iceland and their eruptions4 ,we will begin with the well-known volcano of ,skaptar ,jkul4 ,the following description of this volcano has been taken from a book on ,iceland by ,e4 ,henderson1 published in ,boston1 #ahca4 ,skaptar ,jkul lies in the south central part of ,iceland about forty odd miles from the coast4 ,it takes its name from the ,skaptar ,river1 down whose channel the lava flowed its entire distance of forty miles from the ocean4 ,skaptar ,jkul consists of about twenty conical hills lying along one of the fissures that extends from northeast to southwest4 ,it appears from ,henderson's account that people living in the neighborhood of ,skaptar ,jkul were greatly alarmed by repeated earthquakes that were felt at different times from the first to the eighth of ,june1 #aghc4 ,these earthquake shocks increased in number and violence1 so that the people left their homes and awaited in terror the coming catastrophe4 ,on the morning of the eighth a prodigious cloud of dense smoke darkened the air1 and the surrounding land soon became covered with ashes1 pumice1 and brimstone4 ,as is common with eruptions in ,iceland1 that have been preceded by long periods of rest1 the heat produced by the escaping lava and the sulphurous gases1 melted such quantities of ice that great floods were produced in the rivers4 ,on the #ajth of ,june vast torrents of lava that had been escaping from the craters entered the valley of the ,skaptar ,river1 and commenced flowing through its channel4 ,immense quantities of steam were produced1 and1 in less than twenty-four hours1 the river was completely dried up1 for the lava had collected in the channel1 which in many places flows between high rocks from #djj to #fjj feet in height and nearly #bjj feet in breadth1 and had not only filled the river to its brink1 but had overflowed the adjacent fields to a considerable extent1 and flowing along the cultivated banks of the river destroyed all the farms in its path4 ,on gaining the outlet1 where the channel of the ,skaptar emerged into the plain1 it might have been supposed that the burning flood would have at once spread over the low fields1 which lay immediately before it1 but1 contrary to all expectations1 this flow was for a time stopped by an immense unfathomed abyss in the river's bed1 into which it emptied itself with great noise4 ,when this chasm was at last filled1 the lava increased by fresh flows1 rose to a prodigious height1 and breaking over the cooled mass1 proceeded south towards the plain4 ,in the meantime the thunder and lightning1 together with subterranean roars1 continued with little or no intermission4 ,on the #ahth of ,june1 #aghc1 another dreadful eruption of red hot lava came from the volcano4 ,this flowed with great velocity and force over the surface of the cooling stream that had been thrown out principally on the tenth of the month4 ,floating islands consisting of masses of flaming rock were seen on the surface of the lava stream1 and the water that had been banked up on both sides of the stream was thrown into violent boiling4 ,in the meantime people living along the ,hverfisfloit1 the next largest river to the east of the ,skaptar1 had not yet been visited by the lava streams4 ,it is true that their vegetation had been destroyed by showers of red hot stone and ashes1 and that both atmosphere and water were filled with poisonous substances4 ,the land had also been plunged in utter darkness1 so that it was scarcely possible at noonday to distinguish a sheet of white paper held up at the window from the blackness of the wall on either side4 ,but the molten lava streams had not yet reached the people of this valley and they hoped that the eruption would soon be over1 and that the lava flow would continue to follow the ,skaptar4 ,on the #c;d of ,august1 however1 they were alarmed by seeing steam escaping from the ,river ,hverfisfloit1 and soon all its water was dried up1 and a fresh lava flow poured down upon them4 ,as in the case of the ,skaptar1 the melted rock completely filled the empty channel to the brink1 and then overflowing1 covered the low grounds on both sides1 so that by the ninth of ,august it had reached the open and level country near its mouth and in the course of a few hours spread itself for a distance of nearly six miles across the plain4 ,this flow continued after the end of ,august1 and1 indeed1 even as late as the month of ,february1 #aghd1 when a new eruption took place in this part of the country4 ,hecla1 another well-known volcano in ,iceland1 situated about thirty miles from the southern coast1 consists of three peaks1 the central of which is the highest4 ,its craters form vast hollows on the sides of these peaks1 and at the time of the eruption in #agff were covered with snow4 ,hecla is believed to have been an active volcano long before ,iceland was inhabited4 ,no less than twenty-three eruptions have been recorded between ,a4 ,d4 #ajjd and the great eruption of #agff-fh4 ,volcanic history frequently repeats itself4 ,there had been no great eruption of ,hecla for a period of about twelve years1 and the people living in the neighborhood were congratulating themselves on the belief that the mountain was becoming actually extinct1 and that therefore they need not trouble themselves about eruptions4 ,others1 however1 more farseeing1 pointed out the fact that the lakes and rivers in the vicinity did not freeze1 and that the amount of water they contained was greatly decreased4 ,the following description of the great eruption of ,hecla that was remarkable both for its violence1 as well as for the time during which it continued1 is taken from ,symington's ,sketches of ,faroe ,islands and ,iceland3 ,on the #dth of ,april1 #agff1 there were some slight shocks of an earthquake1 and early next morning a pillar of sand1 mingled with fire and red hot stones1 burst with a loud thundering noise from its summit4 ,masses of pumice1 six feet in circumference1 were thrown to the distance of ten or fifteen miles1 together with heavy magnetic stones1 one of which1 eight pounds weight1 fell fourteen miles off1 and sank into ground still hardened by the frost4 ,the sand was carried towards the northwest1 covering the land1 #aej miles round1 four inches deep1 impeding the fishing boats along the coast1 and darkening the air1 so that at ,thingore1 #adj miles distant1 it was impossible to know whether a sheet of paper was white or black4 ,at ,holum1 #aee miles to the north1 some persons thought they saw the stars shining through the sand-cloud4 ,about mid-day1 the wind veering round to the southeast1 conveyed the dust into the central desert1 and prevented it from totally destroying the pastures4 ,on the #ith of ,april1 the lava first appeared1 spreading about five miles towards the southwest1 and on the #bc;d of ,may1 a column of water was seen shooting up in the midst of the sand4 ,the last violent eruption was on the #eth of ,july1 the mountains1 in the interval1 often ceasing to eject any matter2 and the large stones thrown into the air were compared to a swarm of bees clustering around the mountain-top2 the noise was heard like loud thunder forty miles distant1 and the accompanying earthquakes were more severe at ,krisuvik1 eighty miles westward1 than at half the distance on the opposite side4 ,the eruptions are said to be in general more violent during a north or west wind than when it blows from the south or east1 and on this occasion more matter was thrown out in mild than in stormy weather4 ,where the ashes were not too thick1 it was observed that they increased the fertility of the grass fields1 and some of them were carried even to the ,orkney ,islands1 the inhabitants of which were at first terrified by what they considered showers of black snow4 ,the largest volcano in ,iceland is ,dyngjufjoll4 ,this has on its summit the gigantic crater of ,askja1 some twenty-five square miles in area4 ,this crater is of the intermediate form2 the most general form of volcanoes on the island consisting of a number of craters that closely follow fissures4 ,professor ,johnstrup1 in a report to the ,danish ,government1 on this volcano1 states that the valley of ,askja has been gradually filled by repeated flows of lava from enormous craters on the edge of the mountain4 ,in many places the surface of the earth is covered with bright red pumice stone that was thrown out during an eruption ,march #bith1 #ahge4 ,some of these craters are filled with steam that escapes with an almost deafening roar4 ,the surprising feature of this eruption was the immense quantity of pumice stone that escaped4 ,the volcanoes in the ,nyvatus ,oraefi are entirely different4 ,this barren plain is thirty-five miles in length and thirteen miles in breadth4 ,suddenly on the #ahth of ,february1 #ahge1 a volcano appeared in the centre1 and four other craters were formed at subsequent dates4 ,the mass of lava that was thrown out of these openings has been estimated at #aj1jjj1jjj1jjj1jjj cubic feet1 or eighteen times the estimated mass of lava that has been emitted from ,vesuvius between #agid and #ahee4 ,this lava is basalt4 ,,chapter ,v ,,vesuvius ,the old ,greeks and ,romans had but little knowledge of volcanoes4 ,they only knew the volcanic mountains in the ,mediterranean ,sea4 ,here there are three volcanic regions3--one in the neighborhood of ,naples2 one including ,sicily and the neighboring islands1 and the other that of the ,grecian ,archipelago4 ,some idea can be had of these three regions from a map of the ,mediterranean shown in ,fig4 #ab4 ,the principal volcanoes are ,vesuvius1 ,etna1 ,stromboli1 and ,vulcano1 a mountain1 by the way1 that gave its name to all volcanic mountains4 ,in this chapter we will describe the volcano of ,vesuvius1 the most active1 though by no means the largest of the volcanoes of the ,mediterranean4 ,but1 before doing this1 it will be well first to describe briefly the volcanic districts surrounding ,vesuvius4 ,as shown in ,fig4 #ac1 this district includes ,vesuvius1 ,procida1 and ,ischia4 ,illustration3 ,,fig4 #ab4 ,,the ,,mediterranean ,ischia is a small island measuring about five miles from east to west1 and three miles from north to south4 ,there were such terrific volcanic eruptions on this island long before the ,christian ,era1 that several ,greek colonies were forced to abandon it4 ,a colony established long afterwards1 about #chj ,b4 ,c41 by the king of ,syracuse also had to depart4 ,strabo1 the ,grecian geographer 7born about #fc ,b4 ,c471 states that1 according to tradition1 terrific earthquakes occurred on the island a little before his time1 and its principal mountain threw out large quantities of molten rock1 which flowed into the sea4 ,at the time of this eruption there were earthquake waves in the sea1 the waters of which slowly receded1 leaving large portions of the bottom uncovered1 and rushing1 afterwards1 violently over the land1 caused great destruction4 ,it was during this disturbance1 so ,strabo asserts1 that the island of ,procida was formed by being violently torn from ,ischia4 ,illustration3 ,,fig4 #ac4 ,,the ,,volcanic ,,district ,,around ,,vesuvius ,the ,phlegran ,fields was a name given by the ancients to some of the lowlands in the neighborhood of ,naples2 they were believed to be under the special protection of the ,roman gods4 ,when the frequent earthquake shocks shook these fields1 the ,roman people believed that conflicts were taking place between their gods and slumbering giants confined in the regions below the surface4 ,it is more than probable that ,mt4 ,vesuvius has always been the centre of these volcanic disturbances4 ,long before the ,christian ,era1 however1 ,vesuvius1 or ,somma1 the name given to the old crater that then occupied the summit of the mountain1 had been an extinct crater4 ,indeed1 it had been so quiet that the people who lived on its slopes did not appear to know they were living on the slopes of a slumbering volcano4 ,their knowledge of volcanic mountains must have been very limited1 for this mountain with the huge pit at its summit had all the appearance of a volcanic crater4 ,when they climbed to the top of the mountain1 which1 of course1 they frequently did to look after the vineyards they were cultivating on the slopes1 and looked down into the deep pit from the rocks on its edge1 they could see at the bottom of a great central pit three miles in diameter1 a lake1 with room here and there to enable one to walk along its borders4 ,the walls of the precipice were covered with luxuriant vines4 ,when we say that none of the people even suspected that ,vesuvius had ever been in a state of eruption1 we must except some of their learned men4 ,for both ,diodorus ,siculus1 a native of ,sicily1 who lived about #aj ,b4 ,c41 and wrote an ,universal ,history1 containing some forty volumes1 of which only about one-third remain1 and ,strabo1 the ,geographer1 pointed out in a general manner1 that ,vesuvius1 and much of the surrounding country1 looked as if it had been eaten by fire4 ,then1 too1 a ,roman philosopher who lived between ,a4 ,d4 #a and ,a4 ,d4 #fd1 spoke of ,vesuvius being a channel for the eternal fire6 ,let us now endeavor to obtain some idea of the appearance of this region a short time before ,a4 ,d4 #gi1 when ,vesuvius burst forth in a terrific eruption4 ,the slopes of the mountain were covered with the rich vegetation that characterizes this part of ,italy4 ,when most volcanic ashes and lava have been exposed for some time to the atmosphere they make a very fertile soil4 ,now1 this soil on the slopes of ,vesuvius made the vineyards that covered the mountain slopes and the fields for miles around its base1 bear very plentifully1 so that the people lived very comfortably4 ,here and there on the slopes of the mountain large towns like ,herculaneum and ,pompeii had long been established1 while1 in the distance1 was the large city of ,naples4 ,besides these there were numerous populous towns and villages scattered here and there over the plain or on the lower mountain slope4 ,you have all probably read of the ,roman gladiator1 ,spartacus4 ,spartacus was a ,thracian by birth1 and while a shepherd had been taken prisoner by the ,romans and sold to a trainer of gladiators at ,capua4 ,chaffing under the tyranny of the ,romans1 who forced him to fight in the arena with men and beasts1 he revolted against his masters1 and with a band of some seventy followers1 fled to a mountain fastness in the crater of ,vesuvius4 ,proud ,rome sent a few men to recapture him1 with scourges for his punishment1 but they were beaten by ,spartacus4 ,every day dissatisfied men like himself escaped from the ,romans and joined his ranks4 ,rome sent a larger body of men against ,spartacus1 but they also were beaten4 ,at last1 recognizing the gravity of the position1 the ,roman ,prtor1 ,clodius1 was sent against ,spartacus with an army of some three thousand men4 ,clodius caught ,spartacus in the crater and guarded the only space by which it seemed possible for ,spartacus to escape4 ,using the vines that covered the precipitous walls of the crater1 ,spartacus did escape1 and falling unexpectedly on the armies of ,clodius1 routed them4 ,after this victory1 ,spartacus with an army of over #ajj1jjj men overran southern ,italy1 and sacked many of the cities of the ,roman ,campania4 ,during this time ,spartacus defeated one ,roman army after another1 until finally1 in the year #ga ,b4 ,c41 ,crassus was sent against him and vainly endeavored to conquer him4 ,being unsuccessful1 ,crassus urged the ,roman ,senate to recall ,lucullis from ,asia and ,pompey from ,spain1 and finally poor ,spartacus was cut down in a fight he made against ,crassus and ,lucullis4 ,but let us come to the great eruption of ,vesuvius in ,a4 ,d4 #gi4 ,the people living on the slopes of ,vesuvius were not without plenty of warnings of the dreadful catastrophe that was coming4 ,as early as ,a4 ,d4 #fc there was a great earthquake that shook the country far beyond ,naples4 ,in ,pompeii1 then a flourishing city1 the ,temple of ,isis was so much damaged that it had to be rebuilt4 ,even if the earthquake shocks had not foretold the coming eruption1 there were other signs4 ,the height of water in the wells decreased4 ,springs that had never before been known to fail1 dried up completely4 ,these changes1 as we well know1 were due to the red hot lava being slowly forced up from great depths into the tube connected with the crater4 ,the earthquake shocks continued at irregular intervals for sixteen years1 until1 on the #beth of ,august1 ,a4 ,d4 #gi1 about one o'clock in the afternoon1 ,vesuvius burst forth in the terrible eruption that destroyed the towns of ,pompeii and ,herculaneum4 ,pompeii was a seaport town situated near the mouth of the ,river ,sarno1 about fifteen miles southeast of ,naples4 ,it was a beautiful place1 containing many splendid temples4 ,its people for the greater part lived luxuriously1 for ,pompeii was the summer resort of the richer people of ,naples1 some of whom lived there during the hottest months of the year4 ,herculaneum1 the other town1 was nearer ,naples1 only five miles from the city4 ,it was also1 like ,pompeii1 a beautiful town1 and contained many splendid buildings4 ,in each town there were magnificent baths and a large theatre4 ,the inhabitants spent so much of their time in the open air1 or in the baths1 that it was not necessary for them to build very large houses4 ,the houses1 however1 were well built1 and though generally consisting of practically a single story1 were provided with all the luxuries that great wealth could command4 ,on ,august #beth1 ,a4 ,d4 #gi1 severe earthquake shocks again visited this part of the world and ,vesuvius suddenly threw up from its crater an immense column of black smoke1 which1 rising high in the air1 spread out in the form of a huge mushroom1 or1 perhaps1 more like the umbrella pine tree of the neighborhood4 ,rapidly spreading on all sides1 the smoke soon completely shut out the light of the sun1 and wrapped the earth in an inky darkness1 except for a red glare from columns of molten rock that rushed out of the crater4 ,from the dark cloud immense quantities of red hot stones1 pumice1 and volcanic ashes descended on the earth4 ,at the same time there fell a deluge of rain1 caused by the sudden condensation of the enormous amount of water vapor that was thrown out from the crater during the eruption4 ,fortunately1 very few of the people were killed in either of the cities of ,pompeii and ,herculaneum1 although some bodies were found in the ruins4 ,most of the people escaped through the darkness and gloom1 continuing to flee from the city for at least three days4 ,both cities were covered so deep with ashes or mud that the tops of the tallest buildings were no longer visible4 ,pompeii was buried by showers of ashes or volcanic cinders1 and ,herculaneum mainly by vast floods of aqueous lava4 ,so completely were these cities covered that their very existence was at last forgotten4 ,it is true that ,titus1 who was then ,emperor of ,rome1 endeavored to clear away the ashes and rebuild ,pompeii1 but the task was so great that he finally abandoned it4 ,during the year #aeib1 the architect ,fontana1 while superintending the building of an aqueduct1 came across some ancient buildings4 ,at a much later date1 in #agac1 some workmen1 while digging a well in the village of ,portici1 uncovered three marvellously beautiful marble statues4 ,in the year #agch1 the same well was dug deeper1 when traces of the old theatre of ,herculaneum were discovered4 ,some effort was then made to excavate the city and many of the public buildings and private houses were uncovered1 and statues1 mosaics1 wall paintings1 and charred manuscripts of papyrus were found4 ,a few of these have been unrolled and deciphered1 but owing to the difficulty of doing this1 without destroying them1 the greatest number still remain unread4 ,in #ahfj1 the ,italian ,government began a systematic excavation of the buried cities1 and now both ,pompeii and ,herculaneum are thrown open to the sunlight so that one can walk through the old streets1 and look into the houses1 in which1 before ,a4 ,d4 #gi1 the people lived so happily4 ,many interesting stories are told about the discoveries that were made during the government excavations4 ,the skeleton of one of the inhabitants was found grasping a money bag4 ,he might have escaped1 but had gone back to get his money4 ,he got it1 but remained with it4 ,in another place1 the skeletons of a number of people were found in an underground room or cellar of a house1 where were also found some mouldy bread and empty water flasks4 ,instead of leaving the city1 which they might have done1 they had retreated to the underground room for safety1 but the fine volcanic dust drifted in and suffocated them4 ,the younger ,pliny1 the historian1 has given an excellent account of some features of this great eruption4 ,it appears that his uncle was stationed with the ,roman fleet1 in the ,bay of ,naples1 at the time of the eruption4 ,he describes the dark cloud of ashes that was formed over ,vesuvius4 ,he refers to the rapidity with which it spread1 and to the showers of ashes1 cinders1 and stones that it rained down on the earth4 ,his uncle1 the elder ,pliny1 landed on the coast1 and was afterwards killed by a cloud of sulphurous vapor that swept down the side of the mountain4 ,the following letter from the younger ,pliny1 describing his flight with his mother from ,misenum1 is quoted from ,dana's ,characteristics of ,volcanoes4 ,it was now seven o'clock on the morning of ,august #beth1 but the light was still faint and doubtful4 ,the surrounding buildings had been badly shaken1 and although we were in an open spot a little yard between his uncle's house and the sea1 the space was so small that the danger of a catastrophe from falling walls was great and certain4 ,not till then did we make up our minds to go from the town4444 ,when we were free from the buildings we stopped4 ,there we saw many wonders and endured many terrors4 ,the vehicles we had ordered to be brought out kept running backward and forward1 though on level ground2 and even when blocked with stones they would not keep still4 ,besides this1 we saw the sea sucked down and1 as it were1 driven back by the earthquake4 ,there can be no doubt that the shore had advanced on the sea1 and many marine animals were left high and dry4 ,on the other side was a dark and dreadful cloud1 which was broken by zigzag and rapidly vibrating flashes of fire1 and yawning showed long shapes of flame4 ,these were like lightning1 only of greater extent4444 ,pretty soon the cloud began to descend over the earth and cover the sea4 ,it enfolded ,capre and hid also the promontory of ,misenum4 444 ,the flight was continued4 ,ashes now fell1 yet still in small amount4 ,i looked back4 ,a thick mist was close at our heels1 which followed us1 spreading out over the country1 like an inundation4 444 ,turning from the roar in order to avoid the fleeing1 terror-stricken throng1 they rested4 ,hardly had we sat down when night was over us--not such a night as when there is no moon and clouds cover the sky1 but such darkness as one finds in close-shut rooms4 ,one heard the screams of women1 the fretting cries of babes1 and shouts of men4444 ,little by little it grew light again4 ,we did not think it the light of day1 but a proof that the fire was coming nearer4 ,it was indeed fire1 but it stopped afar off2 and then there was darkness again1 and again a rain of ashes1 abundant and heavy1 and again we rose and shook them off1 else we had been covered and even crushed by the weight4444 ,at last the murky vapor rolled away1 in disappearing smoke or fog4 ,soon the real daylight appeared2 the sun shone out1 of a lurid hue1 to be sure1 as in an eclipse4 ,the whole world which met our frightened eyes was transformed4 ,it was covered with ashes white as snow4 ,young ,pliny and his mother returned to ,misenum1 and survived the perils to which they were exposed4 ,it was during this eruption that a large part of the old crater was blown off the mountain by the tremendous force at work4 ,there have been many eruptions of ,vesuvius since the great eruption of ,a4 ,d4 #gi4 ,one of these occurred during the reign of ,severus1 ,a4 ,d4 #bjc4 ,it was during this eruption that an additional part of the old crater of ,somma was blown away4 ,another great eruption occurred ,a4 ,d4 #dgb4 ,then great quantities of volcanic dust were thrown up into the air1 and falling1 covered practically all parts of ,europe1 producing darkening of the sun and great fear as far as the city of ,constantinople4 ,but what was perhaps a still greater eruption occurred during ,december of #afca4 ,this eruption spread great quantities of ashes over the country for hundreds of miles around1 and great streams of mud rushed down the slopes of the mountain4 ,buccini gives the following account of this eruption3 ,the crater was five miles in circumference1 and about #a1jjj paces deep4 ,its sides were covered with brushwood1 and at the bottom there was a plain on which cattle grazed4 ,in the woody parts wild boars frequently harbored4 ,in one part of the plain1 covered with ashes1 were three small pools1 one filled with hot but bitter water2 another with water saltier than the sea1 and a third with water that was hot but tasteless4 ,but at length these forests and grassy plains were consumed1 being suddenly blown into the air and their ashes scattered to the winds4 ,in ,december1 #afca1 seven streams of lava poured at once from the crater and overflowed several villages1 on its flanks1 and at the foot of the mountain4 ,reisna1 partly built over the ancient city of ,herculaneum1 was consumed by the fiery torrent4 ,great floods of mud were as destructive as lava4 ,this is no unusual occurrence during these catastrophes for such is the violence of the rains produced by the evolution of aqueous vapors that torrents of water descend the cone and become charged with impalpable volcanic dust1 and rolling among ashes1 acquire sufficient consistency to deserve the ordinary appellation of aqueous lava4 ,of course1 you will understand that we have given only a few of the most notable of the eruptions of ,mt4 ,vesuvius4 ,since the yea ,a4 ,d4 #aejj there have been no less than fifty-six recorded eruptions1 that of the year #aheg being especially violent4 ,omitting these eruptions we at last come to the great recent eruption of #ahgb4 ,fortunately1 the eruption of #ahgb1 as well as still more recent eruptions that have occurred1 have been more accurately described than have most volcanic eruptions1 for the ,italian ,government1 recognizing the value to the natives of ,italy of a knowledge of what was going on at the crater of ,vesuvius1 has maintained for the past thirty years an observatory on the western part of the mountain4 ,this observatory has been placed in charge of ,prof4 ,luigi ,palmieri1 a well-known student of volcanoes and earthquakes4 ,at this place records are kept of the behavior of the volcano1 of all earthquake disturbances1 as well as other phenomena4 ,at the same time1 by the use of photography1 excellent pictures have been obtained showing the appearance of the sky during an eruption4 ,vesuvius had been in a quiet state from ,november1 #ahdh1 to the year #ahga1 when small quantities of lava flowed continuously for several months4 ,again1 early in #ahgb1 other quiet eruptions of lava continued for weeks at a time4 ,finally1 on ,april #bfth1 of that year1 a violent explosive eruption occurred4 ,the following account has been taken from ,palmieri's report1 entitled1 ,the ,eruption of ,vesuvius in #ahgb4 ,on ,april #bc;d the recording earthquake instruments1 the seismographs1 were greatly affected4 ,on the evening of the #bdth lava streams flowed down the cone in various directions4 ,these streams were continued on the #beth and the #bfth1 so that on the night of the #bfth the observatory lay between two streams of molten lava that threw out so much heat that the glass windows in the observatory were cracked1 and a scorching smell was quite perceptible in the rooms4 ,the cone of the mountain was deeply fissured1 lava escaping freely from all the fissures1 so that the molten rock appeared to ooze from over its entire surface1 or as ,palmieri expressed it1 ,vesuvius sweated fire4 ,this great cracking or fissuring of the cone was accompanied by the opening of two large craters at the summit1 that discharged1 with a great noise1 immense clouds of steam1 dust1 lapilli1 and volcanic bombs4 ,these latter are very curious and consist of masses of soft lava that are thrown high into the air by the outrushing columns of steam4 ,being rotated or spun1 as they rise in the air1 they assume a spherical shape4 ,some of these volcanic bombs were thrown to a height estimated by ,palmieri to have been nearly #d1jjj feet above the top of the mountain4 ,when the height of a projectile is known1 the velocity with which it left the opening from which it was projected or thrown can be estimated1 so that the volcanic bombs must have left the crater at a velocity of about #fjj feet per second4 ,on the #bgth1 in the evening1 the lava streams ceased flowing1 but the dust and lapilli continued to fall during the #bhth and the #bith4 ,on the #cjth the detonations decreased and by the #ast of ,may the eruption was entirely over4 ,palmieri calculated that the quantity of molten rock thrown out during this eruption was sufficient to cover an area of about #a4h square miles to an average depth of about thirteen feet4 ,as we can see from the above descriptions1 the volcanic activity of ,vesuvius is characterized by long periods of rest followed by periods of activity4 ,the periods of rest are measured by years1 and often by centuries2 the periods of activity by days or hours4 ,but ,vesuvius was not to have a long period of rest after its eruption of #ahgb4 ,on the contrary1 shortly after the great disaster of ,martinique in #aijf1 it again became active1 and on the #eth of ,april1 #aijf1 began throwing large blocks of lava out of its central cone1 and on the next day began to throw out large streams of lava1 which1 on ,april #gth1 destroyed a village in the neighborhood4 ,at the same time rumbling sounds were heard1 and violent earthquake shocks shattered the windows of the houses4 ,professor ,matteucci1 the present director of the ,vesuvius ,observatory1 made the following report on ,april the #hth4 ,the eruption of ,vesuvius has assumed extraordinary proportions4 ,yesterday and last night the activity of the crater was terrific1 and is increasing4 ,the neighborhood of the observatory is completely covered with lava4 ,incandescent rocks are being thrown up by the thousands1 to a height of #b1djj feet or even #c1jjj feet1 and falling back form a large cone4 ,another stream of lava has appeared4444 ,the noise of the explosion and of the rocks striking together is deafening4 ,the ground is shaken by strong and continuous seismic movements1 and the seismic instruments instruments employed to record the time1 direction1 and intensity of earthquake movements threaten to break4 ,it will probably be necessary to abandon the observatory1 which is very much exposed to the shocks4 ,the telegraph is interrupted1 and it is believed the ,funicular railroad has been destroyed4 ,on ,april #ith ,matteucci made the following report3 ,the explosive activity of ,vesuvius1 which was so great yesterday1 and was accompanied by very powerful electric discharges1 diminished yesterday afternoon4 ,during the night the expulsion of rocks ceased1 but the emission of sand increased1 completely enveloping me and forming a red mass from six to ten centimeters deep1 which carried desolation into these elevated regions4 ,masses of sand gliding along the earth1 created complete darkness until seven o'clock4 ,several blocks of stone broke windows in the observatory4 ,last night the earthquake shocks were stronger and more frequent than yesterday1 and displaced the seismic apparatus4 ,yesterday afternoon and this morning1 torrents of sand fell4 ,on ,april #ajth ,matteucci sent the following report3 ,last night was calm1 except for a few explosions of considerable force from time to time4 ,at four o'clock this morning the explosions became more violent4 ,the seismic instruments recorded strong disturbances4 ,the eruption of ,vesuvius of #aijf was especially noted for the great quantities of sand and ashes thrown out of the crater4 ,the amount of sand that fell on the roof of the market house at ,monti ,olivetto was so great that the roof fell in4 ,in this eruption there were some six lava streams that poured down the mountain4 ,the most formidable of these was that which descended towards ,torre ,annunziata4 ,here it stopped just short of the wall of the cemetery outside of the town4 ,during this eruption of ,vesuvius1 as in previous eruptions1 clouds of volcanic dust collected in the air1 shutting off the light of the sun4 ,naples was in a state of semi-darkness4 ,the roofs of the houses were covered to a depth of several inches with an exceedingly fine reddish dust4 ,in some places this dust had drifted into heaps fully a yard in depth4 ,,chapter ,,vi ,,other ,,volcanoes ,,of ,,the ,,mediterranean ,the relative positions of the other volcanic mountains of the ,mediterranean ,sea2 i4 e41 ,etna1 ,stromboli1 and the volcanoes of the ,santorin group of the ,grecian ,archipelago1 are shown in the map1 ,fig4 #ab4 ,we will begin with the volcanic mountain of ,etna1 under which1 according to mythology1 the angry gods had buried the rebellious ,typhoon4 ,etna is situated on the island of ,sicily1 immediately southwest of ,italy4 ,it is a much larger mountain than ,vesuvius1 rising1 as it does1 from a circular base about eighty-seven miles around1 to a height of #aj1hdj feet above the level of the ,mediterranean4 ,it forms a conspicuous object when seen either from the ,mediterranean1 or from distant parts of ,italy4 ,the height of ,etna is so great that its slopes can be divided into three distinct climatic zones or belts4 ,the lowest of these lies between the sea and a height of #b1ejj feet4 ,in this zone the mountain slopes are covered with cultivated fields1 olive groves1 orchards1 and vineyards4 ,the middle zone lies between #b1ejj feet and #f1bgj feet4 ,this zone is covered with forests of chestnuts1 oaks1 beeches1 and cork trees4 ,the third and highest zone includes the rest of the mountain1 and may be called the desert zone1 since it is a sterile region1 covered with huge blocks of lava and scori1 and terminating1 in the higher portions1 in a snow-covered plain1 from which the central cone rises4 ,etna is continually sending up columns of steam and sulphur vapor4 ,every now and then it starts in eruption1 throwing out large quantities of lava either from the crater on its summit1 or from some of the #bjj smaller cones or craters that occupy portions of its slopes4 ,on account1 probably1 of its height the eruptions are most frequently on the sides4 ,etna affords a magnificent example of a huge volcanic pile of the ,vesuvian type1 which has been slowly built up by the gradual accumulation of materials that have escaped from its craters4 ,one of the most interesting features of the higher regions of ,etna is an immense chasm rent in a side of the cone near the summit1 and known as the ,val del ,bove4 ,this chasm forms a vast amphitheater4 ,the great force that removed such an immense mass of matter from the cone could not have been the eroding power of water1 since the materials of the cone are too porous to permit streams of any size to rush down the slopes4 ,the force is most probably to be found in some explosive eruption of the mountain1 when a portion of the crater was suddenly blown off1 just as was done in ,vesuvius when a large part of the old crater of ,somma was blown away4 ,what is especially interesting about the ,val del ,bove is the opportunity it affords for studying the interior structure of the mountain1 for it practically enables one to enter to almost the heart of this great volcano4 ,the ,val del ,bove has the shape of a great pit five miles in diameter4 ,it has almost vertical walls1 the height of which varies with their position4 ,those which reach highest up the mountain vary from #c1jjj to #d1jjj feet in height4 ,like ,vesuvius1 ,etna has been split or fissured into great crevices that have been filled with lava during the many eruptions of its central crater4 ,on hardening1 these lava streams form what are known as dikes4 ,as the sides of the mountain are worn away by erosion1 the dikes1 being harder than the rest of the cone1 project from its sides like huge walls4 ,an excellent opportunity for seeing them is afforded in the walls of the ,val del ,bove4 ,sir ,charles ,lyell1 the ,english geologist1 who has carefully studied ,mt4 ,etna1 asserts that this mountain began to be formed during a geological period known as the ,tertiary ,age1 through a crater that opened on the floor of the ,mediterranean ,sea4 ,the material thus thrown out1 collected around the crater and produced a mountainous pile that gradually emerged above the level of the sea1 and on fresh materials continuing to be thrown out1 at length reached its present height4 ,it would appear that at some former time in its history1 there were two vents near the top of the mountain1 the second crater being formed immediately under the ,val del ,bove4 ,soon1 however1 the second and lower crater was closed1 the upper one alone remaining active4 ,the mountain1 therefore1 continued to be slowly raised in the air by the materials brought out through this opening4 ,then came the great explosive eruption during which the side of the mountain was blown off to form the great chasm of the ,val del ,bove4 ,because of its almost constant activity1 ,mt4 ,etna must have been well known to the ancients1 who described some of its most violent eruptions4 ,the following brief notes concerning these eruptions have been taken from ,lyell4 ,according to ,diodorus ,siculus1 an eruption that occurred before the ,trojan war1 caused the people living in districts near the mountain to seek new homes4 ,thucididies1 the ,greek historian1 states that in the sixth year of the ,peloponnesian war1 which would be about the spring of #dbe ,b4 ,c41 a lava stream caused great destruction in the neighborhood of ,campania1 this being the third eruption that had occurred in ,sicily since it had been settled by the ,greeks4 ,seneca1 during the first century of the ,christian ,era1 calls the attention of ,lucullus to the fact that during his time ,mt4 ,etna had lost so much of its height that it could no longer be seen by boatmen from points at which it had before been readily visible4 ,but passing by these very early eruptions of ,etna we come to the great eruption of #affi4 ,this eruption was preceded by an earthquake that destroyed many houses in a town situated in the lower part of the forest zone1 about twenty-five miles below the summit of the mountain1 and ten miles from the sea at ,catania4 ,during this eruption two deep fissures were opened near ,catania4 ,from these such quantities of sand and scori were thrown out1 that1 in the course of three or four months1 a double cone was formed #dej feet high1 which is now known as ,monte ,rosso4 ,but what was most curious was the sudden opening1 with a loud crash1 of a fissure six feet broad reaching down to unknown depths that extended in a somewhat crooked course to within a mile of the summit of ,etna4 ,this great fissure was twelve miles in length and emitted a most vivid light4 ,five other parallel fissures of considerable length opened1 one after another1 throwing out vapor1 and emitting bellowing sounds which were heard at a distance of forty miles4 ,these fissures were afterwards filled with molten rock1 and in this manner were formed the long dikes of porphyry and other rocks that are seen to be passing through some of the older lavas of ,mt4 ,etna4 ,illustration3 ,,fig4 #ad4 ,,mt4 ,,etna ,from ,map of ,state and ,government ,the great lava streams which flowed down the side of the mountain during this eruption1 destroyed fourteen towns and villages1 and at length reached ,catania4 ,a great wall had been raised around this city to prevent the lava from entering it4 ,the molten rock1 however1 accumulated1 until it rose to the top of the wall1 which was sixty feet high1 and then pouring over it in a fiery cascade1 overwhelmed part of the city4 ,it is said that during the first part of its journey1 the lava streams moved over thirteen miles in twenty days1 or at the rate of #afb feet an hour4 ,beyond this1 after the lava had thickened by cooling1 it had a velocity of only twenty-two feet per hour4 ,fig4 #ad represents a plan of ,mt4 ,etna reduced from a map by the ,italian ,government4 ,during the eruption of #ahfe1 a rent was made in the mountain extending from ,mount ,frumento 7,b in the preceding map7 for one and one-half miles1 and six cones from #cjj to #cej feet in height were formed along the fissure4 ,during the eruption of #ahgd1 great fissures three miles in length were formed in the mountain4 ,there exists on the slopes of ,mt4 ,etna vast subterranean grottoes formed by the sudden conversion into steam of great quantities of water that were overwhelmed by the molten mass4 ,these immense volumes of steam produced enormous bubbles in the molten lava4 ,when the lava hardened irregular grottoes were left4 ,lyell describes one of these as follows3 ,near ,nicolosi1 not far from ,monte ,rosso1 one of these great openings may be seen1 called the ,fossa della ,palomba1 #fbe feet in circumference at its mouth and seventy-eight deep4 ,after reaching the bottom of this1 we enter another dark cavity1 and then others in succession1 sometimes descending precipices by means of ladders4 ,at length1 the vaults terminate in a great gallery ninety feet long1 and from fifteen to fifty broad1 beyond which there is still a passage1 never yet explored1 so that the extent of these caverns remains unknown4 ,the walls and roofs of these great vaults are composed of rough bristling scori of the most fantastic forms4 ,besides the eruptions mentioned there have been many others1 such as those of #ahaa1 #ahai1 and #aheb4 ,the last of these was greater than any eruption except that of #affi4 ,it began in ,august1 #aheb1 and continued until ,may1 #ahec1 and was remarkable for the immense quantity of lava thrown out4 ,illustration3 ,,fig4 #ae4 ,,stromboli1 ,,viewed ,,from ,,the ,,northwest1 ,,april1 #ahgd ,we come now to the volcano of ,stromboli4 ,stromboli1 one of the ,lipari islands1 is situated about sixteen miles west of the ,straits of ,messina4 ,its general appearance is shown in ,fig4 #ae4 ,the form of the mountain is that of an irregular four-sided pyramid1 which rises about #c1jij feet above the level of the ,mediterranean1 and stands on the bottom of the sea in water about #c1jjj feet deep4 ,if you carefully examine the appearance of ,stromboli1 as shown in the preceding figure1 you will notice that the flat cloud which hangs over the island is made up of a number of globular masses of vapor1 formed during the peculiar action of the volcano4 ,when examined by night ,stromboli presents a still more curious appearance4 ,since the mountain stands alone1 its height permits it to be seen readily at sea for distances of at least a hundred miles4 ,at night a curious glow of red light may be seen on the lower surfaces of the cloud4 ,this light is not continuous1 but increases in intensity from a faint glow to a fairly bright red light1 then gradually decreases1 and finally dies away completely4 ,after awhile the light again appears1 again gradually decreases1 and disappears1 and this continues until the rising sun prevents the red glow from being any longer visible4 ,stromboli1 therefore1 acts not unlike the flashing lighthouses so common on the sea coasts of all parts of the world4 ,indeed1 it is actually used by sailors in the ,mediterranean for the purpose of showing them their direction4 ,for this reason ,stromboli is commonly called ,the ,lighthouse of the ,mediterranean4 ,as ,judd remarks1 from whom much of the information concerning some of the volcanic districts of the ,mediterranean has been obtained1 the flashing light of ,stromboli differs from that of the ordinary flashing light in two important respects2 viz41 in the intervals that elapse between the successive flashes1 and in the intensity of the light emitted4 ,as you know1 it is necessary that the different lighthouses placed near one another on a coast must have their lights of such a nature that they can be readily distinguished4 ,in order to do this1 the flashing light has been devised4 ,in flashing lighthouses1 the lights only appear at intervals1 one lighthouse being distinguished from another in its neighborhood by the intervals between successive flashes1 or1 sometimes1 indeed1 by the color of some of the flashes4 ,now1 in the case of ,stromboli1 the intervals between the successive glowings of the red lights are very irregular1 varying between one and twenty flashes per second4 ,moreover1 the intensity of the light also varies greatly from time to time4 ,you naturally inquire as to the cause of these flashes of light that are emitted by ,stromboli4 ,if1 as ,judd suggests1 you should climb to the summit of the mountain1 during the daytime1 and look down the inside of the crater1 you could see its black slag bottom crossed by many cracks and fissures4 ,from most of the smaller fissures the vapor of water is quietly escaping4 ,this vapor rises in the air in which it soon disappears4 ,there are1 however1 larger cracks on the bottom of the crater from which1 at more or less regular intervals1 masses of steam are emitted with loud snorting puffs not unlike those produced by a locomotive4 ,from some of the openings molten matter is seen slowly oozing out1 collecting in parts of the crater and moving up and down in a heaving motion4 ,every now and then a bubble is formed on the surface of this liquid4 ,the bubble swells to a gigantic size1 and suddenly bursts4 ,the steam it contained escapes1 carrying fragments of scum which are thrown high into the air4 ,the masses of steam1 formed below the surface of the sticky1 boiling1 lava1 in endeavoring to escape1 force their way through the mass1 blow huge bubbles1 which1 on bursting1 produce the roaring sounds that are heard1 and throwing great columns of vapor in the air1 produce the rounded masses of clouds you can see floating high up in the air over the mountain4 ,at the same time the scum is partially removed from the red hot surface1 its light illumines the lower surface of the overhanging cloud1 which flings it back again to the earth4 ,with the bursting of each bubble1 and the clearing of the scum from the surface of the red hot mass1 the light begins1 increases in intensity1 and then as the scum again begins to collect on the surface1 decreases1 and finally disappears1 and not until the bursting of the next bubble is it again visible4 ,but let us make a study of some of the peculiarities of ,vulcano1 another of the ,lipari islands1 which lies north of ,sicily4 ,vulcano affords a curious example of a volcano that has been harnessed by man1 or made to do work for him4 ,all volcanoes bring from inside of the earth different kinds of chemical substances1 in the form of vapors1 gases1 or molten materials4 ,now1 these materials acting on one another1 produce chemical substances some of which1 such as sal ammoniac1 sulphur1 and boracic acid1 possess commercial value4 ,this is especially true in the case of ,vulcano1 and since the eruptions are not generally violent1 a chemical works has actually been erected by a ,scotch firm on the side of the mountain1 where the materials are collected from the crevices4 ,this effort to harness a volcano was for a time so successful that the same people contemplated the building of great leaden chambers over the principal fissure at the bottom of the crater1 so that the large volumes of ejected vapors might be condensed and collected4 ,but ,vulcano1 like all other volcanoes1 could not be relied on continually to keep the peace4 ,one day it suddenly burst forth more fiercely than usual1 so that the workmen were compelled to abandon the factory and fly down the mountain for their lives1 but not1 however1 before some of them were severely injured by the explosions4 ,vulcano is an instance of a volcano in an almost exhausted or dormant condition4 ,it has had1 however1 many eruptions during the past few centuries1 some of which have been very violent1 for example1 that of #aghc1 and that of #aghf4 ,there still remains to be considered the volcanic region of the ,santorin group of the ,grecian ,archipelago4 ,the island of ,santorin or ,thera1 is the southernmost of the ,cyclades4 ,it is an exceedingly curious island1 being a submerged volcano1 with most of the top of the crater remaining above the waters1 so that the entire island has the shape of an irregular circle or crescent broken at several points4 ,its formation is1 probably1 due to the gradual sinking of a volcanic mountain until its crater has been almost completely submerged1 only the higher parts of the edges of the crater being left above the surface of the waters4 ,suppose1 for example1 a mountain like ,vesuvius at the time the crater ,somma existed1 was sunk below the level of the ,mediterranean until only the highest parts of the crater remained above the waters4 ,if1 now1 one or more volcanic eruptions occurred1 producing craters or volcanic islands inside the submerged rim1 you would have a condition of affairs seen in the island of ,santorin4 ,,chapter ,,vii ,,orizaba1 ,,popocatepetl1 ,,ixtaccihuatl1 ,,and ,,other ,,volcanoes ,,of ,,mexico ,while some of the volcanoes of ,mexico are still in an active condition1 most of them are either only slightly active or are dormant or extinct4 ,humboldt1 the celebrated traveller and geographer1 states that there are only four active volcanic mountains in ,mexico2 namely1 ,popocatepetl1 ,tuxtula1 ,colima1 and ,jorullo4 ,but there are many others1 among which may be mentioned ,orizaba1 ,ixtaccihuatl1 ,xinantecatl1 ,tuxtula1 ,cofre de ,perote1 and ,colima4 ,of course1 you can understand that1 since extinct volcanoes may at any time become active1 in parts of the world where communication with the interior is not good1 many volcanic mountains that have been regarded as extinct may have broken out temporarily1 during historical times1 without their eruptions having been recorded4 ,it was at one time thought that ,popocatepetl was the highest mountain in ,north ,america4 ,more recent measurements1 however1 have shown that there are at least three other mountains in this part of the world1 that are much higher4 ,one of these is the active volcano of ,orizaba that we will now briefly describe4 ,illustration3 ,,fig4 #af4 ,,mexico ,,and ,,central ,,america ,orizaba is situated in the north central part of ,mexico1 about seventy-five miles west of ,vera ,cruz4 ,its ancient ,aztec name was ,cittaltepetl1 or ,star ,mountain4 ,the height of the mountain is #ah1bjj feet4 ,like all high tropical mountains whose summits are snow-clad1 one would pass through the same changes in climate1 in going from its base to its summit1 as in going along the earth's surface from the equator to the poles4 ,near the base of the mountain will be found a tropical climate1 above that a temperate climate1 while in still higher regions1 the climate of the ,arctic region4 ,according to ,russell1 from whose work on the volcanoes of ,north ,america much of the information concerning the volcanoes of ,mexico and ,central ,america has been condensed1 ,orizaba has three craters on its summit4 ,the last recorded eruption took place about the middle of the ,eighteenth ,century4 ,the mountain is now in a dormant or extinct condition1 as may be seen from the fact that its three craters are for the greater part filled with snow4 ,orizaba1 like ,etna1 and many other volcanoes1 has deep fissures extending through its sides4 ,through these1 lava streams have flowed during times when it was active4 ,there are also found on the slopes of this mountain many cones of a type known as parasitic cones4 ,these cones are not caused by materials that have been brought to the surface during an eruption1 but have been formed by the steam passing through lava streams that have come out of the crater during other eruptions4 ,popocatepetl1 or1 as the word means1 ,the ,smoking ,mountain1 is the second highest mountain in ,mexico4 ,according to recent measurements made by the ,mexican ,government1 its height is #ag1hgf feet4 ,popocatepetl is situated on the edge of the great plateau of ,mexico1 forty miles southeast of the ,city of ,mexico4 ,it is a conical mountain1 and is a magnificent object when seen from the ,city of ,mexico1 rising1 as it does1 fully #aj1jjj feet from the elevation of the city1 while on the east it towers for nearly #ah1jjj feet above the level of the sea4 ,this splendid mountain is poetically described by ,russell3 ,seen from the basal plains1 it sweeps up in one grand curve to nearly its full height1--a collossus of three and a quarter miles in elevation1 white with everlasting frost on its summit1 and bathed in the green of palms1 bananas1 oranges1 and mangoes1 at its base4 ,evergreen oaks and pines encircle its middle height1 and above them1 before the ice itself is reached1 occur broad areas of loose sand into which the lavas have been changed by weathering4 ,soft wreaths of sulphurous vapor may at times be seen curling over the crest of the summit crater1--gentle reminders that the days of volcanic activity are not yet necessarily over4 ,popocatepetl takes its name1 ,the ,smoking ,mountain from the fact that gases and vapor are continually being emitted from its summit crater4 ,it has a conical peak with a depression or crater on its summit4 ,the bottom of the crater is crossed by fissures from which small quantities of steam escape1 not1 however1 sufficient to melt all the snow which covers the slopes of the mountain to a depth of from eight to ten feet4 ,a small lake of hot water has collected in the crater from the water derived from the melting snow4 ,this water1 sinking through the porous materials in the cone1 is the source of a great number of large hot springs that occur around the base of the mountain4 ,reclus states that the first to climb to the top of ,popocatepetl was one of ,cortez' officers1 #aeai4 ,another snow-capped volcano1 which rising from the plain of ,mexico is in clear view of the city1 is ,ixtaccihuatl 7,ets-tak'-se-wat-el71 or as the word means in the ancient ,aztec1 ,the ,white ,woman4 ,this mountain1 as measured by ,heilprin1 is #af1ifj feet in height4 ,ixtaccihuatl is now in so dormant a condition that many who have climbed to the top assert that it is not a volcano at all1 since they find no crater on its summit4 ,nor are there any signs of volcanic heat1 the summit being snow clad during summer4 ,the conical form of the mountain1 however1 and the fact that the entire mountain is formed of volcanic rocks1 show beyond doubt that it is an extinct volcano1 whose crater has most probably been completely filled in by the washing away of its sides4 ,xinantecatl is another extinct volcanic mountain situated about forty miles southwest of the ,city of ,mexico4 ,it is about #af1ejj feet high4 ,its name means in the ancient ,aztec language1 ,the ,naked ,lord4 ,it is also sometimes known as the ,nevado de ,toluca1 or ,the ,snow of ,toluca4 ,on the top of the peak are two craters filled with lakes of fresh water4 ,russell states that the larger of these lakes is about thirty feet in depth and contain a peculiar species of fish4 ,tuxtula is another volcano of ,mexico1 situated on the western coast of the ,gulf of ,mexico1 about eighty miles southeast of ,vera ,cruz4 ,it was an active volcano in #affd1 when it threw out molten lava4 ,it then became dormant until ,march1 #agic1 when its long rest was broken by one of the grandest explosive eruptions of modern times4 ,this eruption rivalled in energy the great explosive eruption which blew off the summit of ,coseguina1 in ,central ,america1 in #ahce4 ,as is common in the case of explosive eruptions1 volcanic dust and scori were blown high into the air1 and1 being carried by the winds1 fell on the roofs of houses and on the land at a distance of #aej miles4 ,there have been a number of less violent eruptions of ,tuxtula since #ahce4 ,tuxtula is a comparatively low mountain1 being only #d1ifj feet high1 because much of the mountain was blown away by the eruption of #agic4 ,as ,russell points out1 it is not safe to infer that because an eroded mountain is not lofty it cannot be young or energetic1 since the very energy of some of its eruptions may1 as in the case of ,tuxtula1 blow away a large part of the mountain4 ,a low mountain1 with an unusually large crater1 generally means a mountain that has been visited by a great explosive eruption4 ,another extinct volcano known as the ,cofre de ,perote is situated on the eastern coast of ,mexico1 east of ,ixtaccihuatl1 about thirty miles north of ,orizaba4 ,it takes its name ,cofre de ,perote which means the ,coffin of ,perote1 from its peculiar box-like shape4 ,it was called in the ,aztec language ,nauhcampatepetl1 or the ,four-,ridged ,mountain4 ,cofre de ,perote is in a dormant or extinct condition4 ,we will conclude this brief description of the volcanoes of ,mexico with the volcano of ,colima1 a mountain about #e1ejj feet high situated on the western coast of ,mexico4 ,colima has been active of recent years1 eruptions having occurred in #ahfi1 #ahgb1 #ahgc1 and #ahhe4 ,during these eruptions lava escaped from lateral openings in the sides of the mountain1 these openings being termed by the natives the ,sons of ,colima4 ,,chapter ,,viii ,,coseguina ,,and ,,other ,,volcanoes ,,of ,,central ,,america ,central ,america has a great number of volcanoes extending along nearly all its western coast1 or on the ,pacific side of the country4 ,central ,america consists of a high plain or table-land sloping gently towards the northeast1 but terminating abruptly on the southwest4 ,in the opinion of geologists this table-land consists of the surface of a huge tilted block of the earth's crust1 or1 perhaps1 more probably1 of a series of such blocks1 that are limited on the southwest by a narrow belt of intersecting fractures4 ,it is in these fractures that scores of volcanoes are situated1 together with active craters1 solfataras1 and hot springs4 ,the volcanoes are mainly of the ,vesuvian type4 ,there are so many volcanoes in this part of the world that it will be possible to describe but a few of them4 ,we will begin with the volcano of ,coseguina1 situated on the ,pacific coast of ,nicaragua4 ,its appearance is that of a conical mountain with the top cut off1 and suggests that it is most probably an explosive volcano which has had the top blown away during some of its great eruptions4 ,coseguina is celebrated by reason of its tremendous eruption of #ahce4 ,before the still more tremendous explosive eruption of ,krakatoa in #ahhc1 described in the first two chapters of this book1 ,coseguina shared with ,sombawa1 on the island of ,sumatra1 as being the foremost of explosive volcanoes4 ,it had been estimated that before its eruption of #ahce1 ,coseguina had a height of perhaps #aj1jjj feet1 but so much of it was blown away by this eruption that it now is a little less than #d1jjj feet4 ,the following description of the great eruption of ,coseguina in #ahce has been condensed from an account prepared by ,squier1 published in #ahej4 ,you will note in reading this brief account how closely many of the phenomena resemble those that occurred during the eruption of ,krakatoa in #ahcc4 ,the eruption of ,coseguina was heralded on the morning of ,january #bjth1 #ahce1 by several loud explosions that were heard for a distance of some #cjj miles around the crater of the volcano4 ,then followed an ink black cloud formed directly over the mountain1 which gradually spread on all sides shutting off the light of the sun1 except for a sickly yellowish light4 ,fine sand was thrown from this cloud1 which made it both difficult and painful to breathe4 ,for two whole days the cloud continued to grow denser1 the explosions louder and more frequent1 and the rain of sand thicker4 ,on the third day the explosions were strongest and the darkness greatest4 ,the amount of sand that fell from the cloud was so great that people left their houses1 fearing the roofs would be crushed in by the great weight4 ,this sand fell in large quantities over an area more than #a1ejj miles in diameter1 or1 quoting the language of ,squier3 ,the noise of the explosions was heard nearly as far 7#a1ejj miles74 ,and the ,superintendent of ,belize1 eight hundred miles distant1 mustered his troops1 under the impression that there was a naval action off the harbor4 ,all nature seemed overawed2 the birds deserted the air1 and the wild beasts their fastnesses1 crouching1 terror-stricken and harmless1 in the dwellings of men4 ,the people for a hundred leagues grouped1 dumb with terror1 amidst the thick darkness1 bearing crosses on their shoulders and stones on their heads in penitential abasement and dismay4 ,many believed that the day of doom had come1 and crowded in the tottering churches1 where1 in the pauses of the explosions1 the voices of the priests were heard in solemn invocation to ,heaven4 ,the brightest lights were invisible at the distance of a few feet2 and to heighten the terror of the scene1 occasional lightnings traversed the darkness1 shedding a lurid glare over the earth4 ,this continued for forty-three hours1 and then gradually passed away4 ,it appears that the eruption of ,coseguina was followed by violent earthquake shocks and other evidences of volcanic energy over extended regions4 ,for example1 there were fearful earthquakes along the ,andes1 the worst of which occurred on ,february #bjth1 and continued at the rate of three or four a day up to ,march #fth1 and1 less frequently1 to ,march #agth4 ,it was during one of these earthquakes that the city of ,concepcion1 ,chile1 was so completely destroyed1 that but a single house remained4 ,the same brilliant sunsets and sunrises occurred in different parts of the world after the eruption of ,coseguina1 due to the presence of large quantities of volcanic dust that followed the great eruption of ,krakatoa4 ,the cause of this great explosive eruption of ,coseguina was most probably the same as that which is believed to have caused the eruption of ,krakatoa1 namely1 a large volume of water suddenly gaining access to a mass of liquid lava4 ,volcn del ,fuego is another of the many volcanoes of ,central ,america4 ,it is situated as one of a group of volcanoes on the highest summit of the ,isthmus4 ,this volcanic mountain has a regular cone with regular slopes on all sides1 except on the north1 where a table-like projection1 about #a1jjj feet below the summit1 is all that remains of a vast cone1 the summit of which was blown away1 according to ,russell1 in prehistoric times1 just as was the crater of ,somma on ,vesuvius4 ,there have been in ,central ,america1 since the time of the ,spanish conquest1 some fifty volcanic eruptions sufficiently great to have been recorded4 ,some idea of the activity of ,fuego during this time may be had from the fact that of all these eruptions some twenty were those of ,fuego4 ,at the present time1 however1 the volcano is dormant and apparently almost extinct4 ,the recorded eruptions of ,fuego are nearly all of the explosive type4 ,among the most violent were those that occurred during #aebf1 #aeda1 and #aeha4 ,during #aehb1 #aehe1 and #aehf1 there were eruptions nearly every month1 the most terrible being near ,christmas day in #aehf4 ,other memorable eruptions occurred in #afad1 #afbc1 #afhf1 and #agje1 and at other dates down to ,august #agth1 #ahfj1 from which date to the present time the volcano has been quiet4 ,we will conclude this brief description of the volcanoes of ,central ,america with that of ,volcn de ,agua1 or1 as the word means1 ,the ,water ,volcano4 ,it is situated in ,guatemala near the coast1 and is one of the mountains that occupies the plateau on which ,fuego is situated4 ,the ,volcn de ,agua is one of the most remarkable volcanoes in ,central ,america1 standing1 as it does1 nearly alone1 and rising to an elevation of #c1cej metres 7#aj1ihh ft471 above the level of the sea4 ,it has been extinct for a long time4 ,it has been supposed by some1 from its name1 that this is a volcano that throws out water4 ,others believe that the name comes from the water produced by the melting of the snow that is collected on the sides of the mountain4 ,now there almost always escapes from the craters of volcanoes during violent eruptions immense quantities of water vapor1 which1 condensing1 fall as vast showers of rain that often deluge the surrounding country4 ,in snow-clad mountains1 the escape of lava is often attended by floods caused by the rapid melting of the snow4 ,the water volcano did not1 however1 take its name from either of these facts1 but rather because at the time of the ,spanish invasion1 the crater of the mountain was occupied by a large lake1 and that during an earthquake in #aeda the wall of the crater was broken1 when the lake was poured as an immense stream of water down the side of the mountain1 overwhelming a village which was situated on this slope4 ,that this was the correct origin of the same may be seen from the fact that the crater at the present time still shows the remains of its former lake basin1 and that on the sides of the broken rim an immense ravine can be seen through which the water poured down on the village below4 ,daubeny describes this volcano as follows3 ,the ,volcn de ,agua 7,water-,volcano7 is of enormous height1 being covered with eternal snow1 in the latitude of #ad4 ,captain ,basil ,hall estimates it at more than #ad1jjj feet1 but a recent traveller states it at #ab1fjj4 ,it has the form of a blunted cone clothed with perpetual verdure to its summit4 ,the crater is from forty to sixty yards in depth1 and about #aej in diameter1--the sides and bottom strewed with masses of rock1 apparently showing the effects of boiling water or of fire4 ,by a deluge of water from this volcano in #aebg1 the original city of ,guatemala was overwhelmed2 and the next built1 called the ,old ,city1 ,la ,antiqua1 was ruined by an earthquake in #aggc4 ,the present capital is situated at a distance of eight leagues from the mountain4 ,another volcano in this part of the country is described by ,daubeny as follows3 ,massaya1 near the lake of that name1 was one of the most active vents at the time of the first discovery of the country4 ,its flames were visible twenty-five miles off4 ,its crater was only twenty or thirty paces in diameter2 but the melted lava 'seethed and rolled in waves as high as towers4' ,a story is told of a ,dominican who imagined the fluid lava was melted gold1 and descended into the crater with an iron ladle to carry some away2 but the ladle1 it is said1 melted1 and the monk escaped with difficulty4 ,,chapter ,,ix ,,the ,,volcanic ,,mountains ,,of ,,south ,,america ,the volcanoes of ,south ,america are limited to the ,andes ,mountain ,system that stretches like a huge wall along the entire western side of the continent4 ,the names of the more important of these volcanoes are marked on the map of ,south ,america1 shown in ,fig4 #ag4 ,as will be seen1 this huge mountain wall reaches from ,patagonia on the south to the ,isthmus of ,panama on the north4 ,the arrangement of the volcanoes in ,south ,america is of the linear type4 ,the craters follow one another in more or less straight lines1 or are situated along the lines of great fissures that lie near the ocean4 ,you must not1 however1 suppose that there is a continuous chain of active volcanic mountains from the ,isthmus of ,panama to the southern part of the continent4 ,according to ,lyell1 from lat4 #b ,n41 or from the north of ,quito1 to lat4 #dc ,s4 or south of ,chile1 a total distance including #de of latitude1 there is a succession of districts with active and extinct volcanoes1 or at least with volcanoes that have been quiet during the last three centuries4 ,illustration3 ,,fig4 #ag4 ,,south ,,america ,lyell traces the volcanoes of ,south ,america as follows3 ,the principal line of active vents which have been seen in eruption in the ,andes extends from lat4 #dc #bh' ,s41 444 to lat4 #cj ,s42 to these thirteen degrees of latitude succeed more than eight degrees1 in which no recent volcanic eruptions have been observed4 ,we then come to the volcanoes of ,bolivia and ,peru1 extending six degrees from ,s4 to ,n41 or from lat4 #ba ,s4 to lat4 #ae ,s4 ,between the ,peruvian volcanoes and those of ,quito another space intervenes of no less than fourteen degrees of latitude1 in which there is said to be but few active volcanoes as far as is yet known4 ,the volcanoes of ,quito then succeed1 beginning about #ajj geographical miles south of the equator1 and continuing for about #aej miles north of it1 when there occurs another undisturbed region of more than six degrees of latitude1 after which we arrive at the volcanoes of ,guatemala1 or ,central ,america1 north of the ,isthmus of ,panama4 ,of course1 you must not understand that there are no extinct volcanoes in these gaps4 ,on the contrary1 according to ,daubeny1 we find1 beginning on the north in the ,united ,states of ,colombia1 the lofty volcano of ,tolima4 ,according to ,daubeny's book published in #ahdh1 ,tolima was then constantly emitting steam and sulphur gases from its summit4 ,tolima is situated in the easternmost of the three mountain ranges that extend through this section of the country4 ,it is1 therefore1 at a comparatively great distance from the ocean4 ,tolima was in eruption in #aeie4 ,it again burst out in #ahbf4 ,coming now to ,ecuador we find that this1 the smallest of the ,south ,american ,republics1 contains numerous great volcanic mountains4 ,some of the principal volcanic mountains are ,chimborazo1 #bj1dih feet above the sea2 ,antisana1 #ah1hhj feet2 ,cotopaxi1 #ai1ffj feet2 ,pichincha 7#ag1fdd feet in #ahdh1 ,daubeny71 ,el ,altar1 #af1chc feet4 ,these all lie in ,south ,america on the plateau of ,quito4 ,as ,baron ,alexander von ,humboldt has pointed out1 the volcanic mountains of ,quito are arranged in two parallel chains that extend side by side for a distance of over #ejj miles north into the ,state of ,colombia1 including between them the high plateaus of ,quito and ,lacumbia4 ,according to ,whymper1 however1 who has recently studied this part of ,south ,america1 there is a succession of basins between the mountains1 but there is no such thing as a single valley in the interior of ,ecuador4 ,the extinct volcanoes of ,cayamba1 ,antisana1 and ,chimborazo are the most important4 ,on all three mountains there are old lava streams on their sides4 ,although no craters can be seen on their summits1 yet it is almost certain they once had craters4 ,there is plenty of room on the summit of ,antisana for a cone as great as that of ,cotopaxi4 ,whymper is of the opinion that the snow domes that form the summit of ,chimborazo were at one time two of the highest points of the rim of the old crater4 ,nearly due south of ,quito is the great volcanic cone of ,el ,altar4 ,like all the peaks of this high plateau1 ,el ,altar rises to a great height above the sea1 being at the present time #af1chc feet above the sea4 ,this mountain has an enormous crater that appears to be dormant or extinct1 and is covered with snow4 ,according to the traditions of ,indians1 ,el ,altar1 or1 as they call it1 ,capac ,urcu or ,the ,chief1 was the highest mountain near the equator1 being much higher than ,chimborazo4 ,but during a prodigious eruption that occurred before the discovery of ,america1 and continued uninterruptedly for eight years1 the height of the mountain was considerably reduced4 ,according to ,boussingault1 the fragments of the cone of this celebrated mountain are now spread for great distances around the mountain on the surrounding lowlands4 ,pichincha in ,ecuador1 an extinct volcano1 is situated almost immediately on the equator4 ,it has a height as measured by ,whymper by the barometer1 of #ae1iah feet above the ,pacific4 ,the summit is covered by blocks of pumice4 ,several species of lichens are found at this elevation4 ,according to ,daubeny1 ,pichincha was extinct prior to #aeci1 when it became active4 ,there were also eruptions in #aegg1 #aehg1 and #affh4 ,it was also in activity during #ahca4 ,cayamba1 another volcanic mountain of ,ecuador1 lies to the east of ,pichincha1 a short distance north of the equator4 ,its height is #ai1ahf feet4 ,it is nearly extinct4 ,cotopaxi1 #ai1fhj feet1 is another volcanic mountain of the high plateau of ,quito4 ,cotopaxi is still active4 ,its slopes are covered with snow down to a height of about #ad1hjj feet4 ,between the lower edge of this snow line and the lower slopes of the mountain1 there lies a zone of naked rock4 ,according to ,whymper1 the eruption of ,cotopaxi1 in #ahgg1 was preceded by an unusual degree of activity in the earlier parts of the year4 ,this1 however1 did not cause any alarm until ,june #beth1 #ahgg1 when1 shortly after midday1 an eruption1 attended by tremendous subterranean roars1 began1 and an immense black column shot up into the air for about twice the height of the cone4 ,this eruption was clearly visible at ,quito1 for the wind blew the ashes towards the ,pacific4 ,at this time the summit had not changed its appearance1 but towards #f3cj ,a4 ,m41 on the next day1 another enormous column of ashes rose from the crater4 ,the ashes and cinders were first carried due north by the winds1 and then1 spreading out in all directions1 were subsequently distributed through the air all over the country4 ,at ,quito1 as early as #h ,a4 ,m41 the sky assumed the appearance it generally has at twilight1 and the darkness increased until midday1 when it became as dark as at midnight4 ,indeed1 it was so dark that one could not see his hand before his face4 ,during this eruption1 as is very common in the eruptions of the snow-clad mountains of ,south ,america1 a flood of water1 due to the rapid melting of the snow and ice on the summit1 rushed down the mountain slopes at #aj o'clock ,a4 ,m41 on the #bfth of the month1 almost immediately after the appearance of a stream of lava that began to flow down the mountain4 ,in a few moments the mountain was completely shut off from view by immense columns of steam and smoke4 ,at first1 a low1 moaning sound was heard1 which rapidly increased to a roar1 when a deluge of mud1 mingled with huge blocks of ice and stones1 swept down the mountain1 leaving a desert in its path4 ,it is estimated that at some places this stream moved with a velocity of fifty miles per hour4 ,the general appearance of ,cotopaxi is shown in the accompanying reproduction from the painting by ,frederick ,e4 ,church in the ,lenox ,library1 ,new ,york4 ,according to ,whymper1 who made an ascent of ,cotopaxi in #ahhj1 the crater on the summit has the form of an immense amphitheatre1 #b1cjj feet across from north to south1 and #a1fej feet from east to west4 ,its crest is irregular and notched4 ,the crater is surrounded by perpendicular cliffs4 ,the western side of the volcano is irregular4 ,barometric measurements gave the height of this volcano at #ai1dih feet4 ,its height as taken by ,la ,condamine1 during the early parts of the last century1 was #ai1fje feet1 so that1 according to ,whymper1 assuming as would seem probable1 that this difference in height has not all been due to errors in measurements1 the volcano has grown or increased in height during the last century and a half4 ,chimborazo1 #bj1dih feet1 is another lofty mountain on the plateau of ,quito4 ,this volcano is situated in lat4 #a #cj' ,s41 and is not at the present time in an active condition4 ,it is1 however1 formed entirely of volcanic material4 ,its upper portions are covered with a layer of snow to a level of some #b1fjj feet below the summit4 ,illustration3 ,,cotopaxi ,from a ,painting by ,frederick ,e4 ,church in the ,lenox ,collection of the ,new ,york ,public ,library4 ,by ,permission ,chimborazo has an enormous volcanic summit1 which1 when seen from the ,pacific1 when the air is especially clear after the long rains of winter1 is a most splendid sight4 ,whymper1 who ascended the mountain1 says3 ,when the transparency of the air is increased and its enormous circular summit is seen projected upon the deep azure of blue of the ,equatorial sky1 it represents a magnificent sight4 ,the great rarity of the air through which the top of the ,andes is seen adds much to the splendor4 ,whymper says1 that as far as records are concerned1 there have been no eruptions of ,chimborazo1 which has apparently been an extinct volcano for many years4 ,its crater has been completely buried by a thick cap of ice on its summit1 while what lava streams exist on the mountain are either covered by large glaciers1 or have been removed by erosion1 or hidden by vegetation4 ,chimborazo possesses less of the conical outline than ,cotopaxi4 ,there are steep cliffs towards the summit that have been named by ,whymper the northern and southern walls4 ,they seem to him to have been formed by the violent upheavals of the explosive eruptions that have blown away portions of the cone4 ,there are other volcanoes in this district1 but the above are all we have space for describing4 ,according to ,lyell1 the volcano of ,rancagua1 in ,chile1 lat4 #cd #ae' ,s41 is continually throwing up ashes and vapors like ,stromboli4 ,indeed1 a year seldom passes in ,chile without some earthquake shocks4 ,of these shocks those which came from the side nearest the sea are most violent4 ,the town of ,copiapo was laid waste by these shocks during the years #aggc1 #agif1 and #ahai1 in both instances after intervals of twenty-three years4 ,since the volcanic mountains of ,south ,america are snow-covered the occurrences of volcanic eruptions are apt to be attended by great floods caused by the rapid melting of the snow1 as well as sometimes by the breaking of huge subterranean cavities that are filled with water4 ,according to ,lyell1 the volcanoes of ,peru rise from a plateau from #ag1jjj to #bj1jjj feet above the sea4 ,one of the principal volcanoes of ,peru is ,arequipa1 whose summit is #ah1hgg feet above the level of the sea4 ,the mountain takes its name from the city of ,arequipa1 which is situated not far from its base4 ,it is an active volcano4 ,another volcano1 ,viejo1 is found in lat4 #af #ee' ,s4 ,according to ,lyell1 there are active vents extending through ,chile to the island of ,chiloe to lat4 #cj ,n4 ,aconcagua1 west of ,valparaiso1 in lat4 #cb #ci' ,s41 #bc1jjj feet in height1 the highest mountain in ,south ,america1 is still in an active condition4 ,according to ,scrope1 when the city of ,mendoza was destroyed by an earthquake1 that killed #aj1jjj people1 in ,march1 #ahfa1 it is probable that ,aconcagua was in eruption4 ,there are many other active volcanoes in ,chile1 extending as far south as the volcanoes of ,patagonia1 north of the ,straits of ,magellan as well as others of ,tierra del ,fuego4 ,,chapter ,x ,,volcanoes ,,of ,,the ,,united ,,states ,for some readers this may be a surprising chapter heading1 for it is a general impression that there are no volcanoes in the ,united ,states4 ,it is true that practically all of the volcanoes of this country are dormant or extinct4 ,they have1 however1 at one time been exceedingly active1 and1 if reports are correct1 some of them were active during comparatively recent times4 ,nearly all of the volcanoes of the ,united ,states lie west of the meridian of ,denver4 ,these volcanoes belong to two distinct types1 either the ,vesuvian type with built up cones1 or the plateau or fissure type already referred to4 ,the following brief description of the volcanoes of the ,united ,states has been collated1 for the greater part1 from ,wallace's excellent book on the volcanoes of ,north ,america4 ,crossing the ,united ,states on the ,southern ,pacific ,railroad one's attention is caught1 in ,arizona1 by a magnificent group of mountains known as the ,san ,francisco ,mountains4 ,the highest peak of these mountains reaches #ab1efb feet above the level of the sea1 and #e1gjj feet above the surface of the plateau on which the mountains stand4 ,illustration3 ,,fig4 #ah4 ,,the ,,united ,,states ,according to ,g4 ,k4 ,gilbert1 the ,san ,francisco ,mountain group is formed of a variety of lava known as trachyte1 that is of comparatively recent ejection1 possibly of a geological age called the ,tertiary4 ,the lava forming the mountains escaped through a number of crater cones1 some of which can still be seen in the neighborhood4 ,some of these craters are now in almost as perfect a condition as the day they were formed4 ,indeed1 to one looking at them from a neighboring elevation1 they appear so fresh1 and so little affected by the climate1 that one might almost believe that the lava had just flowed out of the craters1 and has not yet hardened4 ,nevertheless1 geologists are sure they have been formed long before man appeared on the earth4 ,in one of these craters a lake of fresh water has collected4 ,another extinct volcano of the ,united ,states is ,mt4 ,taylor in ,new ,mexico1 nearly east of the ,san ,francisco ,mountains4 ,this mountain rises from the surface of a high table-land1 or1 as it is called in this part of the world1 a mesa4 ,the surface of the plateau is covered with a thick lava stream from which ,mt4 ,taylor rises to a height of #aa1cij feet above the level of the ocean4 ,this mesa1 or table-land1 is forty-seven miles in length from northwest to southeast1 and about twenty-three miles in breadth4 ,its general elevation is about #h1bjj feet4 ,the plateau rises about #b1jjj feet above the surface of the level land that surrounds it4 ,all these #b1jjj feet have been removed by erosion4 ,the table-land from which ,mt4 ,taylor rises has not been eroded by the action of the rain1 rivers1 and other weathering agencies like the surface of the country surrounding it1 because of a covering of lava that has been spread over its surface to a depth of about #cjj feet4 ,mt4 ,taylor is formed almost entirely of lava that has escaped through a single opening and has built up a high cone around it4 ,the volcano is now quite extinct1 so that the original form of the mountain has been greatly changed by erosion4 ,you will remember1 when we were discussing the general subject of volcanoes1 in the beginning of this book1 that we spoke of volcanic mountains being bottled up after an eruption1 by the hardening of the lava which remained in the crater and the tube that connects the crater with the place from which the lava had been derived4 ,we then spoke of this hardened mass being known as a volcanic plug1 or stopper1 explaining how the volcano could never again erupt through its old crater unless it could develop sufficient force to blow out or remove this stopper4 ,now besides the crater at the top of ,mt4 ,taylor there were several others in the eroded region surrounding the mesa1 or high table-land1 from which ,mt4 ,taylor rises4 ,when1 therefore1 the erosion which removed the #b1jjj feet of rocks on all portions of the old mesa that were not protected by the coating of lava1 these old mountain plugs were too hard to be worn away or eroded1 and were1 therefore1 left projecting into the air like vast pyramids4 ,if you should ever visit ,mt4 ,taylor and should go to the eastern border of this mesa1 and look over the eroded plain1 you would see in the lowlands a part of the places from which the #b1jjj feet of matter have been slowly eroded4 ,dutton describes the beautiful panorama that is to be seen as follows3 ,the edge of the mesa suddenly descends by a succession of ledges and slopes1 nearly #b1jjj feet into the rugged and highly diversified valley-plain below4 ,the country beneath is a medley of low cliffs and bluffs1 showing the browns and pale yellows of the ,cretaceous sandstones and shales4 ,out of this confused patchwork of bright colors rise several objects of remarkable aspect4 ,they are apparently inaccessible eyries of black rock1 and at a rough guess1 by comparison with the known altitudes of surrounding objects1 their heights above the mean level of the adjoining plain may range from #hjj to #a1ejj feet4 ,the blackness of their shade may be exaggerated by contrast with the brilliant colors of the rocks and soil out of which they rise1 but their forms are even more striking4 ,these black piles are the necks or lava plugs of extinct volcanoes4 ,they rise above the level of the plain because1 being harder than the surrounding rocks1 they have resisted erosion4 ,in some cases these necks or plugs have been converted by shrinkage1 on cooling1 into beautiful columns1 somewhat of the type of the basaltic columns of the ,giant's ,causeway4 ,it would be difficult to count the number of volcanic necks that can be seen near the edge of the mesa4 ,one's attention is at once attracted to some dozen of these piles1 which are especially striking on account of their great size1 and ominous black color1 but the number is by no means limited to this dozen4 ,there are hundreds of them4 ,fig4 #ai gives some idea of a part of the view from the edge of the mesa1 and ,fig4 #bj the appearance of two of these volcanic necks4 ,but besides high volcanic mountains such as the ,san ,francisco ,mountains and ,mt4 ,taylor1 there are1 in different parts of the ,united ,states1 to be found fragments of huge craters from which1 in the geological past1 immense quantities of lava have escaped4 ,in some instances these craters are but fragments of huge craters1 that1 like the crater of ,mt4 ,somma1 in ,vesuvius1 have been nearly completely blown away by some unrecorded explosion during the far past4 ,illustration3 ,,fig4 #ai4 ,,panorama ,,from ,,the ,,mesa ,,at ,,the ,,edge ,,of ,,mt4 ,,taylor ,from ,u4 ,s4 ,geological ,survey ,a crater of this type1 known as ,ice ,springs ,crater1 is situated in the desert valley west of the ,wahsatch ,mountains1 some #abe miles south of ,salt ,lake ,city1 ,utah4 ,this crater is especially interesting from the fact that it occupies a position on a plain that was formed by the deposition of sediment in an immense lake that covered this part of the ,united ,states very long before man lived on the earth4 ,we are alluding to ,lake ,bonneville1 a lake that existed in a geological time known as the ,glacial ,epoch4 ,this lake occupied the territory now filled by the ,great ,salt ,lake of ,utah1 but towards the close of the ,glacial ,epoch it was immensely larger than it is now4 ,this can be shown not only by the presence of shore lines1 that are clearly marked on the sides of the surrounding mountains1 but also by the ancient lake beaches1 and deltas1 that are common in the district1 so that instead of there being the comparatively limited area of ,great ,salt ,lake as marked on the maps of to-day there was a lake that had an area of #ai1gej square miles1 that covered an area on which at least #bjj1jjj people dwell4 ,illustration3 ,,fig4 #bj4 ,,volcanic ,,necks1 ,,edge ,,of ,,mesa ,,at ,,mt4 ,,taylor ,from ,u4 ,s4 ,geological ,survey ,a similar lake1 known as ,lake ,lehontan1 existed at the same time1 covering large areas in the western parts of ,nevada4 ,coming now to ,ice ,springs ,craters in ,utah1 we find here three small craters formed of scori and lapilli 7volcanic ashes consisting of small angular stony fragments74 ,near them lies a fragment of a much larger crater known as the ,crescent4 ,in some respects this crater was not unlike the crater of ,somma that surrounded ,mt4 ,vesuvius4 ,it was not1 however1 as large1 having a diameter of only #b1bjj feet4 ,from these craters streams of basalt flowed until they covered considerable areas4 ,a still more recent crater known as ,tabernacle ,crater is situated four miles south of the ,ice ,springs ,crater4 ,tabernacle ,crater takes its name from the building known in ,salt ,lake ,city as the ,tabernacle4 ,according to ,gilbert1 this crater was formed at a time when ,lake ,bonneville stood at a comparatively low level1 or when the water was only from fifty to seventy-five feet above the bottom of the valley on which the crater now stands4 ,at that time an explosive volcanic eruption occurred on the bottom of the lake1 and the rim of the crater1 built up by this explosion1 was gradually pushed above the surface of the lake1 so as to shut out its waters4 ,extinct volcanic craters1 not unlike those of ,utah1 occur also near ,ragtown1 in ,nevada1 in a district known as the ,carson ,valley ,desert1 in one of the broadest areas of what was once ,lake ,lahontan4 ,ragtown is twenty-two miles southwest of ,wadsworth on the ,central ,pacific ,railroad4 ,at the present time there are two circular depressions or volcanic craters filled with pools of strongly alkaline water known as the ,ragtown ,pond1 or ,soda ,lake4 ,the large lake covers an area of #bfh-a_/b acres4 ,its greatest diameter is over #d1jjj feet4 ,without going into a detailed description it will suffice to say that the larger crater probably was destroyed by an explosive volcanic eruption4 ,another intensely alkaline lake that fills an extinct volcanic crater is the ,mono ,lake1 situated in ,mono ,valley in ,california at the eastern base of the ,sierra ,nevadas4 ,it has an area of about #bjj square miles4 ,the centre of the lake has two small islands named ,pacha and ,negit4 ,immediately south of ,mono ,lake are a number of craters that occupy portions of what was once apparently a fissure extending in a general north and south direction4 ,the highest of these craters are in the neighborhood of #b1ejj feet4 ,but leaving these inconspicuous craters1 let us briefly examine some of the higher mountain peaks of the ,united ,states that are of volcanic origin4 ,one of the most conspicuous of these is ,mt4 ,shasta4 ,this mountain is situated in ,california1 at the northern end of the ,sierra ,nevadas4 ,it has a height of #ad1cej feet4 ,it is a snow-clad mountain of a conical form1 and is a conspicuous object in the landscape1 because it stands alone4 ,mt4 ,shasta is a double-coned mountain4 ,besides the cone on its summit there is a well-developed cone known as ,shastina on the western side of the mountain1 #b1jjj feet lower than the main summit4 ,there are well-defined lava streams on the slopes of ,mt4 ,shasta4 ,one of these1 which issued from the southern side of the mountain at an elevation of #e1ejj feet1 divided into two streams4 ,one of these streams is twelve miles in length4 ,the other entered the canyon of the ,sacramento ,river1 thus displacing the water4 ,coming now to the ,cascade ,mountains1 in ,oregon and ,washington1 we will find in them a number of giant peaks of volcanic origin4 ,the most important of these are in regular order from south to north1 as follows3 ,mt4 ,pitt1 #i1gfj feet2 ,mt4 ,mazana1 #h1bbc2 ,mt4 ,union1 #g1hha2 ,mt4 ,scott1 #g1abc2 ,three ,sisters1 ,mt4 ,jefferson1 #aj1bjj1 and ,mt4 ,hood1 #aa1bbe1 in ,oregon2 ,mt4 ,adams1 #i1egj2 ,mt4 ,st4 ,helen's1 #i1gej2 ,mt4 ,rainier1 #ad1ebe1 and ,mt4 ,baker in ,washington1 #aj1hgg4 ,nearly all these mountains have craters either on their summits or on their sides4 ,they are extinct volcanic mountains1 that were1 for the most part1 thrown up during the ,tertiary ,geological ,period1 so that they have all been greatly affected by erosion4 ,one of the most remarkable of the above volcanic mountains is ,mt4 ,mazana1 in ,oregon4 ,this mountain has on its summit an approximately circular cavity from five to six miles in diameter1 that is occupied by a lake of water known as ,crater ,lake4 ,this lake is #f1bci feet above the level of the sea1 and has a depth of #a1ige feet4 ,it is surrounded by nearly vertical walls ranging from #ijj to #b1bjj feet deep1 so that the vast caldera of which this great depression consists has a depth of at least #d1jjj feet4 ,mt4 ,pitt1 situated about sixty miles north of ,mt4 ,shasta1 in southern ,oregon1 has a regularly shaped volcanic cone1 and the remnant of a crater at its summit4 ,the ,three ,sisters and ,mt4 ,jefferson lie to the north of ,mt4 ,pitt4 ,like the others they are ancient volcanic mountains4 ,but little is accurately known concerning them4 ,mt4 ,hood1 #aa1bbe feet high1 rises from the crest of the ,cascade range in ,northwest ,oregon1 about twenty-five miles south of the ,columbia ,river4 ,mt4 ,hood is an exceedingly majestic mountain4 ,at its summit there are only portions of the walls of the original crater4 ,when ascended in #ahhh1 streams of sulphur vapor were escaping from fumaroles on its northeastern slopes1 at an elevation of #h1ejj feet above the sea4 ,mt4 ,adams and ,mt4 ,st4 ,helen's lie to the north of ,mt4 ,hood4 ,mt4 ,adams about sixty miles to the north1 and beyond this1 ,mt4 ,st4 ,helen's4 ,accurate information concerning the summit of ,mt4 ,adams is still lacking4 ,mt4 ,st4 ,helen's in ,washington has more of a conical summit4 ,russell states that according to frontiersmen1 ,st4 ,helen's has been in a state of activity within the past fifty years4 ,a ,french-,canadian asserts that the mountain was in actual eruption during the winter of #ahda-dc1 that at this date the light from the volcano was sufficiently bright to enable one to see and pick up a pin in the grass at midnight near his cabin some twenty miles distant4 ,mt4 ,st4 ,helen's was ascended in #ahhi1 when fumaroles were found on the northeast side4 ,mt4 ,rainier in ,washington is plainly visible from ,puget ,sound4 ,it is a most magnificent mountain4 ,the summit has a bowl-shaped crater1 of an almost perfectly circular form4 ,the inside of the crater1 when last ascended1 was filled to within thirty or thirty-five feet of its rim with ice and snow4 ,there was1 however1 evidences of heat1 since numerous jets of steam were seen issuing from its interior rim4 ,mt4 ,baker1 ,washington1 is the northernmost of the volcanoes of the ,cascade ,mountains1 south of the boundary line between the ,united ,states and ,canada4 ,but little is known of this mountain4 ,the summit appears as a conical peak from ,puget ,sound1 so that its form would seem to show that it is of volcanic origin4 ,according to ,gibbs1 officers of the ,hudson ,bay ,company1 as well as the ,indians1 declared that ,mt4 ,baker was in eruption in #ahdc1 when it broke out at the same time as ,mt4 ,st4 ,helen's1 covering the country with ashes4 ,there are but few volcanoes in the ,rocky ,mountains which extend from north to south through the ,united ,states at a considerable distance to the east of the ,sierra ,nevadas and ,cascade ,ranges4 ,the ,spanish ,peaks1 situated in the southeastern part of ,colorado about sixty miles south of ,pueblo1 are the remains of ancient volcanoes4 ,two of the most prominent of these peaks rise from #ab1gbj to #ac1fbj feet above the sea4 ,we shall make no effort to attempt to describe the volcanic mountains that may exist in those portions of the ,rocky ,mountain ,ranges or the ,cascade ,range lying in ,canada4 ,comparatively little is known of them1 but inasmuch as volcanic activity has been manifested in ,alaska1 it would seem highly improbable1 as ,russell remarks1 that volcanoes should suddenly cease at the northern boundaries of the ,united ,states and then begin again at the most southern part of ,alaska4 ,it will be sufficient to say that ,mt4 ,edgecome1 situated on an island in the neighborhood of ,sitka1 is of volcanic origin1 and that the ,aleutian ,islands1 beginning at ,alaska on the east at the head of ,cook's ,inlet1 extend westward through the ,peninsula of ,alaska to the ,peninsula of ,kamtschatka for a distance of nearly #a1fjj miles4 ,this belt1 which is called by ,russell the ,aleutian ,volcanic ,belt1 contains numerous volcanoes that are known to have been active in historical times4 ,mt4 ,wrangell1 on the ,copper ,river1 #bjj miles northeast of the head of ,cook's ,inlet1 is a lofty volcanic mountain that is said to have been in eruption in #ahai1 and at the time of last report was still throwing out columns of steam4 ,while much remains to be ascertained about the volcanoes of the ,aleutian ,islands1 it would appear that there are active volcanoes on twenty-five of these islands1 on which some forty-eight craters have been found4 ,eruptions are common in the district4 ,,chapter ,,xi ,,the ,,catastrophe ,,of ,,martinique ,,and ,,the ,,volcanic ,,islands ,,of ,,the ,,lesser ,,antilles ,the ,west ,indies ,island chain consists of two groups of islands2 i4 e41 the ,greater ,antilles1 including ,cuba1 ,jamaica1 ,hayti1 and ,porto ,rico1 on the west1 and the chain of the ,lesser ,antilles on the east4 ,the ,lesser ,antilles consists of two parallel chains1 the westernmost of which is for the greater part mountainous with peaks several thousand feet in height4 ,all these islands are volcanic4 ,the chain on the east consists of low1 calcareous rocks1 or rocks consisting largely of lime4 ,in the western chain the islands beginning on the south are1 ,grenada1 ,st4 ,vincent1 ,st4 ,lucia1 ,martinique1 ,dominica1 ,guadeloupe1 ,montserrat1 ,nevis1 and ,st4 ,eustace1 while in the calcareous chain are found the ,tobago1 ,barbadoes1 and others4 ,prior to #aijb1 the greatest volcanic eruption in this part of the world occurred on the island of ,st4 ,vincent1 with the volcano of ,soufrire4 ,although the forces displayed were exceedingly great1 yet they become insignificant when compared with the appalling eruption that took place in ,martinique only a short time ago2 namely1 ,may the #hth1 #aijb1 when the volcano of ,mt4 ,pele1 situated on the northwestern part of the island1 burst into an eruption so terrible that in destruction of life it far exceeded the eruption of ,krakatoa1 although the amount of energy causing the eruption was much smaller4 ,illustration3 ,,fig4 #ba4 ,,the ,,lesser ,,antilles ,heilprin1 in a book called ,mt4 ,pele and the ,tragedy of ,martinique1 from whom most of the information of this chapter has been obtained1 calls attention to the fact that before the eruption of ,pele there were plenty of warnings for those intelligent enough to note them4 ,for two or three weeks prior to ,may #hth1 #aijb1 the volcanic activity of ,pele had been rapidly increasing1 the mountain throwing out clouds of ashes and sulphurous vapors from its crater4 ,by ,april #beth the sulphurous vapors had so increased in quantity as to make breathing difficult in ,st4 ,pierre4 ,the ashes fell on the surrounding country and by the #b;d of ,may had so covered the streets of ,st4 ,pierre as to stop traffic4 ,three days later1 ,may #fth1 shortly before noon1 an avalanche of mud poured down the slopes of the mountain with the rapidity of an express train4 ,these torrents of mud and water deluged the towns and villages in the neighborhood4 ,the activity of ,mt4 ,pele increased until the morning of ,may #hth1 #aijb1 when1 almost at exactly #h ,a4 ,m41 an eruption occurred1 so terrible in its effects that in two minutes the city of ,st4 ,pierre was almost completely destroyed4 ,st4 ,pierre1 the principal town of ,martinique1 is situated on the island of ,martinique1 on the northwestern coast1 about ten miles southwest of ,mt4 ,pele4 ,st4 ,pierre was settled as far back as #afce4 ,it is situated on an open roadstead without any harbor4 ,that there were many points of resemblance between the position of ,st4 ,pierre and the destroyed city of ,pompeii will be recognized as the description of the catastrophe is given4 ,st4 ,pierre was a beautiful city1 and formed the natural outlet to one of the richest districts in ,martinique for the production of sugar cane and cocoa4 ,it contained many fine houses1 the homes of planters1 wealthy bankers1 merchants1 and shippers1 who1 besides their regular houses in the city1 had constructed handsome villas on heights on the outskirts of the city4 ,the houses were to a great extent one or two stories in height1 and were in many cases surrounded by fine gardens4 ,the city extended along the coast for about two miles4 ,the streets were well lighted4 ,the eruption of ,mt4 ,pele on ,may #hth1 #aijb1 was of a very unusual character1 containing a feature that--with the exception of a volcanic eruption of ,soufrire1 a volcanic mountain on the neighboring island of ,st4 ,vincent1 and an eruption of ,kilauea in ,hawaii--so far as ,i am aware1 never before occurred4 ,this was a blast of highly heated air1 mingled with white hot or incandescent dust1 that swept down the side of the mountain with a velocity of one or two miles per minute1 or possibly more4 ,nearly all of the people in ,st4 ,pierre were killed4 ,from the appearance of the bodies it seemed that death was practically instantaneous1 and was due either to scorching or burning1 or asphyxiation by the breathing of highly heated air4 ,the number of people so killed1 including almost the entire population of ,st4 ,pierre1 as well as a number of adjoining settlements1 was not less than #cj1jjj4 ,the zone of absolute destruction was limited to an area the extent of which did not greatly exceed eight or nine square miles4 ,on the outskirts of this zone the destruction1 though considerable1 was less complete4 ,there was almost an entire absence of great earthquake shocks during the eruption4 ,following the terrible eruption of ,may #hth were a number of less violent eruptions on ,may #bjth1 #bfth1 ,june #fth1 ,july #ith1 and ,august #cast4 ,according to ,heilprin these eruptions were of the same character as that of ,may #hth4 ,there has been considerable discussion as to the exact causes of the tornadic incandescent blast that caused the awful destruction of life4 ,without entering this discussion it is sufficient to say that it is now generally considered that the blast consisted of highly heated air1 and super-heated steam loaded with great quantities of finely divided red hot or even white hot dust particles4 ,while1 perhaps1 the force producing the awful eruption of ,mt4 ,pele was greatly excelled in the case of many other volcanic eruptions2 such as ,papandayang1 in #aggb2 ,asamayama1 in #aghc2 ,skaptar ,jkul1 in #aghc2 ,tomboro1 in #ahae2 ,coseguina1 in #ahce2 and ,krakatoa1 in #ahhc2 yet1 in the words of ,heilprin1 in intensity and swiftness of its death-dealing blast 444 the eruption of ,may #hth1 and of later dates1 stands unique in records of volcanic manifestations4 ,while the amount of ashes that accompanied the blast of white hot steam and air was comparatively small1 yet during the time between this and the subsequent eruptions1 the amount of ashes that were thrown from the surface of ,mt4 ,pele was exceedingly great4 ,according to ,russell1 in a paper on the volcanic eruptions of ,martinique and ,st4 ,vincent1 in #aijb1 the amount of ashes and solid matter generally thrown out from the crater of ,mt4 ,pele would be equal to #dj1jjj1jjj cubic feet every minute1 or one and a half times the sediments discharged by the ,mississippi in the course of a whole year4 ,according to ,heilprin1 however1 the actual amount of dust thrown from the crater of ,mt4 ,pele was1 probably1 #ejj times greater than the amount discharged by the ,mississippi ,river in the course of a year1 and1 consequently1 considerably greater than that of all the rivers of the world combined1 or1 as he says3 ,mont ,pele has now been in a condition of forceful activity for upwards of two hundred days2 can we assume that during this time it may have thrown out a mass of material whose cubical contents are hardly less than a quarter of the area of ,martinique as it now appears above the waters8 ,one is1 indeed1 almost appalled by the magnitude of this work1 and yet the work may even be very much greater than is here stated4 ,we ask ourselves the questions1 what becomes of the void that is being formed in the interior8 ,what form of new catastrophe does it invite8 ,there can be no answer to a question of this kind--except in the future happening that may be associated with this special condition4 ,but geologists must take count of the force as being one of greatest potential energy1 whose relation to the modelling and the shaping of the destinies of the globe is of far greater significance than has generally been conceived4 ,a curious circumstance connected with the eruption of ,mt4 ,pele was the most pronounced electric and magnetic disturbances4 ,moreover1 as in the case of the eruption of ,krakatoa1 there were the same after glows or red sunsets and sunrises due to the presence of fine volcanic dust in the higher regions of the air4 ,these phenomena were observed over widely separated areas4 ,it appears that this great eruption in ,martinique was preceded by severe earthquakes in the northern part of ,south ,america1 especially in ,colombia and ,venezuela4 ,the most marked was the great earthquake which on ,april #ahth destroyed the city of ,guatamaula2 this was1 perhaps1 the most destructive earthquake that has occurred in the ,western ,hemisphere since the great earthquake of #ahab1 that destroyed the city of ,caracas4 ,indeed1 ,professor ,milne suggests that it was this earthquake that brought about the eruption of ,mt4 ,pele4 ,soufrire1 on the island of ,st4 ,vincent1 had a great eruption on ,may #gth1 #aijb1 one day before the awful eruption of ,mt4 ,pele4 ,no lava flowed during this eruption4 ,there were1 however1 great discharges of mud1 due to a lake that before the eruption filled the top of a depression known as the old crater which lay southwest of a new crater1 or the crater that was formed during the eruption of #ahab4 ,the old crater was nine-tenths of a mile across from east to west1 and eight-tenths of a mile from north to south4 ,the depth to the crater floor was from #a1jjj to #b1djj feet4 ,the surface of the new and shallow boiling lake which occupied the deepest part of the floor during the latter part of ,may1 and from ,june to ,august1 was estimated to be only #a1bjj feet above the level of the sea4 ,the sheet of water that occupied it before the eruption being several hundred feet higher4 ,soufrire did not fail to give warnings of its coming eruption4 ,rumblings were heard two days before the explosion4 ,on ,may #eth1 #aijb1 fishermen who crossed the lake noticed that the water was disturbed and agitated4 ,on the ,tuesday following1 ,may #fth1 great clouds were thrown out during the afternoon1 and the volcano was illumined by a reddish glare of fire4 ,the first explosion was heard shortly before two o'clock on the following day and the volcano burst into activity4 ,the explosions1 together with great discharges of pumice1 ashes1 and boulders1 followed one another rapidly4 ,a column of steam was shot up into the air for a height of #cj1jjj feet4 ,the severest paroxysm came shortly after ten ,a4 ,m41 and was succeeded by others nearly as violent during the next few hours4 ,by this time a reddish curtain of clouds nearly shut out the island from view1 and rapidly advanced over the land and descended on the sea4 ,this eruption caused a loss of life of about #a1cej4 ,this eruption of ,mt4 ,soufrire was accompanied by the same tornadic blast of glowing air4 ,there was not1 however1 any single blast quite as severe as that which attended the eruption of ,pele on ,may #hth1 #aijb4 ,,chapter ,,xii ,,some ,,other ,,noted ,,volcanic ,,mountains ,since the limits of our book will prevent any further description of volcanic districts or regions1 we must content ourselves with descriptions of some of the noted of the remaining volcanoes1 although many we will thus omit contain great wonders4 ,as we have already seen from the description of ,krakatoa1 the island of ,java near which ,krakatoa is situated is especially noted not only for the great number of its volcanic mountains1 but also for the frequency and severity of their eruptions4 ,perhaps the most destructive eruption of any of the volcanic mountains of ,java was of a volcanic mountain called ,papandayang4 ,this volcano1 situated on the southern coast of the island1 is #g1jcd feet in height1 and was in eruption in #aggb4 ,according to ,scrope1 from whom the details of this eruption have been obtained1 two others of the many volcanoes on ,java1 situated at #ahd and #ceb geographical miles respectively from ,papandayang1 broke out at the same time into active eruption1 although several intervening cones were undisturbed4 ,the eruption of ,papandayang was of the explosive type1 a large part of the mountain being broken off by the great force of the eruption1 and its materials scattered far and wide over the surrounding country4 ,during this eruption forty villages with their inhabitants were buried by great showers of ashes4 ,an area of fifteen by six miles was left in the shape of a huge pit by the great eruption4 ,it was at first believed by some that this pit was due to the actual sinking in of the ground1 but a more careful study has shown that it was in reality caused by the great force of the eruption1 being1 in point of fact1 a vast explosive crater that was formed by the expulsion of the materials that formerly filled it4 ,some idea of the great extent of this eruption of ,papandayang may be had by the size of this huge crater that was six by fifteen miles in diameter4 ,another great volcanic mountain in ,java that had a terrific eruption was ,galungoon1 or ,galung ,gung4 ,according to ,lyell1 from whom the facts of this eruption have been obtained1 prior to this eruption the slopes of the mountain were highly cultivated and densely populated4 ,there was a circular pit or crater on the summit of the mountain1 but there had been no traditions of any eruptions prior to #ahbb4 ,in ,july1 #ahbb1 the waters of the ,kunir ,river1 one of the small rivers that flow down the slopes of the mountain1 were observed to become hot and turbid4 ,on the #hth of ,october1 #ahbb1 a terrific explosion was suddenly heard1 accompanied by great earthquake shocks1 when immense columns of hot water and boiling mud1 mixed with burning brimstone1 ashes1 and lapilli1 were thrown violently like a great waterspout from the opening in the mountain1 with such enormous violence that great quantities fell across the ,river ,tandoi1 forty miles distant1 while the valleys in the neighborhood were filled with a burning torrent4 ,the rivers overflowed their banks and produced great destruction by floods of burning and boiling materials that washed away all the villages and cultivated fields in their path4 ,during this eruption an extended area was covered with boiling mud in which were completely buried the bodies of many of those who perished4 ,so great was the violence with which the boiling mud1 cinders1 etc41 were thrown out of the mountain that they entirely failed to fall on many of the villages in the immediate neighborhood1 while the more remote villages were completely destroyed and buried out of sight under the mud4 ,the first eruption continued for nearly five hours4 ,during several days following the eruption1 torrents of rain fell1 which produced floods in the rivers that covered the country far and wide with thick layers of mud4 ,four days after the great eruption1 that is1 on the #abth of ,october1 #ahbb1 a second and still more violent eruption occurred1 when immense quantities of hot mud were again thrown out of the crater4 ,great blocks of hardened lava called basalt were thrown a distance of seven miles from the volcano4 ,this eruption was accompanied by a violent earthquake4 ,it was during this eruption that a huge piece of the side of the cone was blown out1 not unlike the case of the ,val del ,bove on ,mt4 ,etna4 ,the surrounding country was covered with mud4 ,the immense quantity of materials thus thrown out of the side of the mountain produced changes in the courses of several rivers1 thus causing great floods which in the single night of ,october #abth drowned #b1jjj people4 ,during these eruptions there were #aad villages destroyed1 with a total loss of life of about #d1jjj4 ,there is a volcanic mountain on the island of ,sumbawa that is noted for the very destructive eruption that occurred on it in ,april1 #ahae4 ,if you examine the map of the ,sunda ,islands chain1 you will see that the island of ,sumbawa lies immediately east of a little island called ,lombock1 about #bjj miles east of ,java4 ,this eruption of ,sumbawa was of the most frightful violence1 and1 indeed1 with the exception of ,krakatoa and ,pele1 was one of the greatest eruptions in historic times4 ,like all great eruptions1 that of ,sumbawa gave plenty of signs of its coming4 ,during ,april1 #ahad1 the volcano manifested considerable increase in its activity1 and ashes fell on the decks of vessels sailing past the island4 ,the eruption began on ,april #eth1 #ahae1 but reached its greatest violence on the #aath and #abth of ,april4 ,according to ,lyell1 the sound of the explosion was heard at the island of ,sumatra at a distance of #igj geographical miles towards the west1 and in the opposite direction it was heard for a distance of #gbj miles4 ,the destruction of life was terrible4 ,out of a population of #ab1jjj in the province of ,tomboro1 only twenty-six people escaped with their lives4 ,like many other great eruptions the shooting upwards of the great column of matter from the crater produced a violent whirlwind that carried people1 horses1 cattle1 and almost every movable object high into the air1 and tore up huge trees by their roots4 ,immense quantities of ashes fell over the surrounding country1 or were carried towards ,java to the west a distance of #cjj miles1 while on the north they were carried towards ,celebes for a distance of #bag miles4 ,cinders covered the ocean towards the west two feet thick and several miles in length1 so that ships could hardly make their way through them4 ,the darkness in ,java produced by the dense ash cloud was greater than had ever before been experienced with the single exception of the great eruption of ,krakatoa4 ,a considerable quantity of this volcanic dust was carried to the islands of ,amboyna and ,banda1 the last named island being at a distance of #hjj miles east of the volcano4 ,this eruption of ,sumbawa was attended by great lava streams that covered vast areas of the land and afterwards poured into the sea4 ,as in the case of the explosive eruption of ,krakatoa great waves were produced in the ocean all along the coasts of ,sumbawa1 and surrounding islands4 ,the sea suddenly rose from two to twelve feet4 ,a great wave rushed up the mouths of the rivers1 and at the town of ,tomboro1 on the west side of ,sumbawa1 an area of land was sunk in the waters and remained permanently covered by eighteen feet of water4 ,the most important of the still active volcanoes of ,japan is ,assamayna4 ,this mountain was in terrible eruption during the autumn of #aghc1 when dense showers of ashes thrown out of the crater darkened the sky1 turning the day into night1 and1 falling on the cultivated fields around the mountain1 changed them into deserts4 ,during the eruption some forty-eight villages were destroyed by showers of ashes and red hot stones and thousands of the inhabitants were either killed directly by the stones and ashes1 or died from starvation1 since their fields were covered with ashes for miles around to a depth of from two and a half to five feet4 ,another terrible eruption in ,japan was in the volcanic mountain of ,wunzen1 or ,onzen-,gatake4 ,this occurred during #agia-ic4 ,during the last eruption of this volcano1 #ec1jjj people lost their lives1 either by reason of the eruption of the volcano1 or by huge waves set up in the ocean by an earthquake4 ,,chapter ,,xiii ,,jorullo1 ,a ,,young ,,volcanic ,,mountain ,you must not suppose that when we speak of ,jorullo as a young volcanic mountain that we mean young in the sense that you or ,i might be called young1 but young as regards mountains2 for ,jorullo1 now a great mountain range1 had no existence before the year #agei1 and that would make the mountain a little less than #aej years old1 which so far as mountains are concerned may properly be regarded as quite young4 ,the story of ,jorullo is very interesting1 and affords an excellent example of the great scale on which modern volcanic eruptions take place during historical times4 ,if you examine the map of ,mexico on page #hf you will see that ,jorullo lies #agj miles southwest of the city of ,mexico1 and #ajh miles from the ,pacific ,ocean1 which is the nearest large body of water4 ,this mountain is of especial interest because1 if old traditions are to be believed1 it was thrown up during practically a single night4 ,this wonderful event took place on an elevated plain or plateau1 called the ,plain of ,malpais1 that lies between #b1jjj and #c1jjj feet above the level of the ocean4 ,the plain was situated in a part of ,mexico that was celebrated for the growth of the finest cotton and indigo in the world4 ,it formed the large estate of a wealthy planter1 ,seor ,pedro de ,jorullo1 who lived at his ease as a wealthy planter is apt to do in tropical countries like ,mexico4 ,jorullo's plantation was covered by an especially fertile soil1 since it was formed by the deposits of volcanic ashes1 dust1 tufa1 etc41 produced1 most probably1 by neighboring volcanoes long before man appeared on the earth1 for the plain of ,malpais was bounded by hills that were composed of volcanic materials4 ,there had1 however1 been no signs of volcanic activity in the neighborhood4 ,it had indeed been quiet1 so far as volcanic eruptions were concerned1 since the time of the discovery of ,america by ,columbus1 until the middle of the last century4 ,the fertile fields of the ,jorullo plantation were watered by two rivers1 or as we would probably call them1 brooks1 the ,cuitamba and the ,san ,pedro4 ,signs were not wanting of the coming calamity4 ,during ,june1 #agei1 subterranean sounds were heard of a low rumbling character1 which every now and then increased until they resembled in intensity the sounds produced by the firing of large guns4 ,these sounds were accompanied by earthquake shocks that greatly terrified the people and caused them to flee from their homes4 ,nothing1 however1 occurred1 so1 becoming accustomed to the noises1 the people returned to their houses4 ,the noises and tremblings ceased for over two months1 until1 on the #bith of ,september1 #agei1 they were again heard1 and a terrible eruption began4 ,a long fissure opened in the earth1 extending generally from northeast to southwest4 ,from this fissure flames burst out1 fragments of burning rock and stone1 together with large quantities of ashes were thrown to great heights in the air1 and were followed by streams of molten rock4 ,six volcanic cones were formed along the fissure4 ,the highest of these cones is what now constitutes the volcanic mountain of ,jorullo1 which then reached a height of at least #a1fjj feet above the level of the plain4 ,from its cone were thrown out great quantities of lava of the same type as that which escaped from the craters of many volcanic islands such as ,hawaii and ,iceland1 namely1 basaltic lavas4 ,this eruption1 which began on the #bith of ,september1 #agei1 continued until the month of ,february1 #agfj4 ,the account as above given was obtained by ,humboldt1 who visited the country some fifty-six years after the eruption4 ,this story was told him by the ,indians1 but was also recorded in verse by a ,jesuit priest1 ,raphael ,landiva1 a native of ,guatemala4 ,according to the account given ,humboldt by the ,indians1 it appears that when a long time after the eruptions had quieted down1 they had returned to their old homes with the hope of cultivating part of the grounds1 they found the plains still too hot to permit their living on them4 ,according to ,lyell1 there was around the base of the cone1 spreading from them as a centre over an area of some four square miles1 a convex mass1 about #eej feet in height1 most of the surface of which was covered with thousands of small flattish conical mounds from six to nine feet in height4 ,these1 together with numerous large fissures that crossed the plain in different directions1 served as points for the escape of sulphur vapors1 as well as for the vapors of hot water4 ,during the escape of lava from the craters in #agei1 the molten rock1 spreading over the plain1 ran into the channels of the river or brooks before named1 driving out the water4 ,this water reappeared at the base of the mountain in numerous hot springs4 ,humboldt thought that the conical mountains had been lifted or raised by the formation of huge bubbles formed under the lava1 thus causing it to assume a shape not unlike that of a huge bladder4 ,this opinion1 however1 has not been accepted by geologists at the present time4 ,scrope points out that this was probably the origin of the little conical mounds that covered the surface of the principal conical mounds but was not1 in all probability1 the cause of the mound itself4 ,he says3 ,with regard to the disputed question as to the origin of the raised plain of the ,malpais1 ,m4 de ,saussure1 the last and most trustworthy visitor1 entirely confirms the opinion which ,i ventured to proclaim in #ahbe1 that ,humboldt was mistaken in supposing it to have been 'blown up from beneath like a bladder1' and that it is merely an ordinary current of lava1 which1 owing to its very imperfect liquidity at the time of its issue from the volcanic vent1 as well as to the overflow of one sheet or stream upon another1 had acquired great thickness about its source1 gradually thinning off towards the outer limit of the elliptical area it covered4 ,if you have been able to follow the above you will see that ,mr4 ,scrope means that in his opinion the cone of ,jorullo is a lava cone like that we have already studied on ,mt4 ,loa or ,mt4 ,kilauea1 or1 in other words1 that the lava as it came out from the opening on the top of ,jorullo1 flowed in all directions around the opening1 thus building up a mountain in the form of a flat lava cone4 ,perhaps one of the reasons ,humboldt had for believing the entire elevation of ,jorullo to be due to the formation of a huge bladder was the fact that the plain on which the cone is situated1 when struck1 gave out a sound as though there was a vast hollow space below it4 ,this was especially the case when the hoofs of the horses driven over its surface produced sounds as though they were moving over the summit of a hollow dome-like space below4 ,but1 as ,lyell points out1 this was probably only due to the fact that the materials forming the cone were very light and porous4 ,according to ,burkhardt1 a ,german mining engineer who visited ,jorullo in #ahbg1 there appears to have been no other eruptions of the volcano since the time of ,humboldt's visit4 ,mr4 ,burkhardt descended to the bottom of the crater and observed that small quantities of sulphurous vapors were still escaping4 ,the small cones or hornitos1 however1 on the slopes had entirely ceased emitting steam4 ,it appeared1 too1 that the twenty-four years that had passed since the time of ,humboldt's visit1 the rich soil of the surrounding country had permitted the successful cultivation of some crops of sugar cane and indigo4 ,russell appears to doubt the reliability of the information obtained by ,humboldt concerning ,jorullo4 ,he suggests that a poetical account by the ,jesuit missionary from whom ,humboldt obtained much of his information was not apt to possess marked scientific accuracy4 ,while1 however1 this may be true1 yet to a certain extent it seems entirely probable that the principal facts were as above given4 ,the following account as given by ,humboldt1 is taken from a translation made in the early part of #ahjj3 ,the affrighted inhabitants fled to the mountains of ,aguasarco4 ,a tract of ground from three to four square miles in extent1 which goes by the name of ,malpays1 rose up in the shape of a bladder4 ,the bounds of this convulsion are still distinguishable in the fractural strata4 ,the ,malpays1 near its edge1 is only twelve metres above the old level of the plain called the ,playas de ,jorullo2 but the convexity of the ground thus thrown up increases progressively towards the centre1 to an elevation of #afj metres 7#ebd4h ft474 ,those who witnessed this catastrophe from the top of ,aguasarco assert that flames were seen to issue forth for an extent of more than half a square league1 that fragments of burning rocks were thrown up to prodigious heights1 and that through a thick cloud of ashes1 illuminated by the volcanic fire1 the softened surface of the earth was seen to swell up like an agitated sea4 ,the rivers of ,cuitamba and ,san ,pedro precipitated themselves into the burning chasms4 ,the decomposition of the water contributed to invigorate the flames1 which were distinguishable at the city of ,pascuaro1 though situated on very extensive table-land #a1djj metres 7#d1eib ft47 elevated above the plains of ,las ,playas de ,jorullo4 ,eruptions of mud1 and especially of strata of clay enveloping balls of decomposed basalt in concentrical layers1 appeared to indicate that subterranean water had no small share in producing this extraordinary revolution4 ,thousands of small cones1 from two to three metres in height1 called by the indigenes ovens1 issued forth from the ,malpays4444 ,in the midst of the ovens1 six large masses1 elevated from #djj to #ejj metres each above the old level of the plain1 sprung up from a chasm1 of which the direction is from ,n4 ,n4 ,e4 to the ,s4 ,s4 ,e4 ,this is the phenomenon of the ,montenovo of ,naples1 several times repeated in a range of volcanic hills4 ,the most elevated of these enormous masses1 which bears some resemblance to the puys de l',auvergne1 is the great ,volcan de ,jorullo4 ,it is continually burning1 and has thrown up from the north side an immense quantity of scorified and basaltic lavas containing fragments of primitive rocks4 ,these great eruptions of the central volcano continued till the month of ,february1 #agfj4 ,in the following years they became gradually less frequent4444 ,the roofs of the houses of ,queretaro were then covered with ashes at a distance of more than forty-eight leagues in a straight line from the scene of the explosion4 ,although the subterranean fire now appears far from violent1 and the ,malpays and the great volcano begin to be covered with vegetation1 we nevertheless found the ambient air heated to such a degree by the action of the small ovens1 that the thermometer at a great distance from the surface and in the shade rose as high as #dc ,c4 7#aji #d' ,f474 ,,chapter ,,xiv ,,mid-,,ocean ,,volcanic ,,islands ,besides the volcanoes we have already described1 there are many others situated in mid-ocean far from any continent4 ,a brief description will be given of a few of these4 ,all the three great central oceans1 the ,pacific1 the ,atlantic1 and the ,indian1 contain numerous volcanic islands1 some of which rise many thousands of feet above the general level4 ,we will begin with a description of some of the more important volcanic islands of the ,pacific4 ,it was first pointed out by ,kotzebue1 and afterwards by ,darwin1 that all the islands of the ,pacific ,ocean can be divided into two great classes1 the high islands and the low islands4 ,all the high islands are of volcanic origin1 while the low islands are of coral formation4 ,it is the opinion of ,dana1 who has made a careful study of coral formations1 especially in the ,pacific1 that in all probability even the low islands of the ,pacific were originally volcanic1 and that the deposits of coral had been made along their shores after their volcanoes had become extinct4 ,the islands of the ,pacific1 like the shores of the continents and most of their mountain ranges1 extend in two great lines of trend1 or general direction1 which intersect each other nearly at right angles4 ,these lines extend from the southeast to the northwest1 and from the northeast to the southwest respectively1 those extending in a general direction from southeast to northwest being the most common in the ,pacific4 ,now1 perhaps1 the greatest number of the earth's volcanoes are arranged along fissures1 or cracks in the earth's crust4 ,the craters are situated along the cracks1 the openings being kept clear at the crater1 and gradually closing elsewhere1 probably by pressure4 ,in other words1 most of the volcanoes follow one another along more or less straight lines4 ,for example1 in the western part of ,south ,america they follow the ,andes ,mountains4 ,a similar arrangement exists in the volcanoes of ,central ,america1 ,mexico1 and the ,united ,states4 ,now1 this is especially true of mid-ocean volcanoes of the ,pacific which lie along lines extending from southeast to northwest1 or from northeast to southwest1 though mainly along the former4 ,some of the volcanic islands of the ,pacific have already been described or referred to1 as1 for example1 the ,aleutian ,islands1 which stretch in a curved line from the southwestern extremity of the peninsula of ,alaska to ,kamtschatka on the coast of ,asia4 ,we have already described the island of ,hawaii1 the great volcanoes of the ,sandwich ,islands chain1 and besides these there are in the ,north ,pacific the ,ladrone ,islands1 lying east of the ,philippines4 ,some of the principal remaining islands are3 the ,fejee ,islands1 which are volcanic1 with numerous hot springs and craters4 ,the ,friendly ,islands1 with the peak of ,tafua1 #b1ach feet high1 an active volcano with a large crater always burning1 and two other volcanoes1 ,apia1 and ,upala4 ,tahiti1 to the east1 is at present extinct4 ,one of its mountains1 ,orobena1 said to be #aj1jjj feet high1 has a crater on its summit4 ,the ,marquesas1 still further to the east1 are also volcanic4 ,all of these islands lie generally in the lines of the northeast trend4 ,the ,tongan or ,new ,zealand ,island chain extends in the direction of the northeast trend4 ,this1 as you will see1 is the direction in which the two islands of ,new ,zealand extend4 ,the ,tongan ,island chain is continued to the south through ,auckland and the ,macquaire ,islands to #eh ,s4 ,towards the north1 in almost the same line1 are the ,kermadec ,islands near #cj ,s4 ,there are several active volcanoes in ,new ,zealand4 ,an explosive eruption of ,tarawera1 in ,new ,zealand1 in #ahhc1 continued for several days1 and was followed1 three days afterwards1 by an outburst in an active volcano in the ,bay of ,plenty1 and two months afterwards1 by a violent outburst in a volcano on the island of ,ninafou in the ,tongan ,islands4 ,coming now to the ,atlantic ,ocean we find a number of volcanic mountains in the deep waters near mid-ocean4 ,the principal of these1 besides ,iceland1 are the ,azores1 the ,canaries1 ,cape ,verde ,islands1 ,ascension ,island1 ,st4 ,helena ,island1 and ,tristan d',acunha4 ,the ,peak of ,pico1 in the ,azores1 rises to a height of #g1jaf feet4 ,the ,peak of ,teneriffe1 in the ,canaries1 reaches the height of #ab1bbe feet4 ,teneriffe is a snow-capped mountain4 ,it has a cone on its summit with precipitous walls like ,vesuvius4 ,sulphurous vapors are continually formed at its summit1 but no flames can be seen4 ,in the ,cape ,verde ,islands is to be found the active volcanic mountain of ,fuego1 rising #g1jjj feet above the sea4 ,it has a central cone that has been broken down on one side like that of ,somma on ,vesuvius4 ,fuego was in eruption in #aghe1 and also in #agii4 ,ascension ,island1 south of the equator1 is formed entirely of volcanic materials4 ,this island rises from an apparently granite floor on the bed of the ocean1 in water #ab1jjj feet deep4 ,st4 ,helena lies further to the south4 ,it is an extinct volcano1 and has the remains of a crater on its summit with lava dikes in various parts of the island4 ,tristan d',acunha is an isolated mountain that lies in the ,south ,atlantic1 south of ,st4 ,helena1 #a1ejj miles from ,africa1 the nearest land4 ,it is an extinct volcano that rises from a depth of #ab1aej feet to a height of #g1jjj feet above the sea4 ,it has a truncated cone on its summit and a lake of pure water in its old crater4 ,there are only a few volcanic islands in the ,indian ,ocean4 ,kerguelen ,island lies in the southern waters4 ,st4 ,paul and ,amsterdam to the north1 lying near #dj ,s4 lat41 as well as the ,crozet ,islands1 are extinct volcanoes4 ,in the ,arctic ,ocean is the volcanic island of ,jan ,mayen4 ,in the ,antarctic ,ocean1 as far as is known1 there are only two volcanoes1 ,mt4 ,erebus and ,mt4 ,terror4 ,mt4 ,erebus1 #ab1djj feet high1 is an active volcano4 ,mt4 ,terror1 #aj1iij feet high1 is an extinct volcano4 ,,chapter ,,xv ,,submarine ,,volcanoes ,a submarine volcano is a volcano that erupts on the bed of the ocean with its crater covered by the waters4 ,many of the great volcanic mountains of the world began as submarine volcanoes4 ,a crater first opened on the floor of the ocean1 and lava escaping1 was heaped up around the opening1 until it emerged above the surface as an island4 ,as we have seen1 the island of ,iceland is believed to have begun in this way4 ,such1 too1 in all probability1 was the origin of ,hawaii1 ,vesuvius1 ,etna1 and ,santorin4 ,but besides the volcanic mountains that were thrown up during the geological past1 there are others that have been called into existence while man has been living on the earth4 ,we will now describe a few islands that have been formed in this manner by submarine volcanic eruptions4 ,that volcanic eruptions1 or at least something that greatly resembles eruptions1 occur on the bed of the ocean too far below the surface to permit them to be directly seen from above1 has been shown in a number of cases where the captains of vessels have reported that in certain parts of the ocean1 jets of water1 or steam1 and pillars of flame have been seen rising to great heights from the surface of the water1 and that in certain regions sulphurous smoke has also been seen4 ,during such occurrences1 the water is agitated1 as if it were being violently boiled4 ,moreover1 these parts of the ocean are shaken by severe earthquake shocks4 ,another evidence of submarine volcanic eruptions is to be found in great quantities of ashes1 scori1 or pumice stone1 that are seen spread out over the surface of the ocean after the commotions referred to in the preceding paragraph4 ,still another proof is that parts of the ocean whose waters were previously very deep are found to have suddenly shoaled4 ,of course1 the best proof is the appearance of rocky reefs or small islands thrown up above the surface of the water1 especially where volcanic cones appear4 ,while in many cases the new islands thus thrown up are subsequently washed away by the waves1 yet some have continued above the water4 ,one of the most noted instances of the formation of an island by a submarine volcano was ,sabrina1 which was thrown up in #ahaa1 in the ,atlantic ,ocean1 off the shores of ,st4 ,michael in the ,azores ,islands4 ,sabrina had a cone that was #cjj feet in height4 ,it did not long remain above the waters1 however1 being soon washed away by the waves4 ,it is interesting to note that in the same part of the ocean where ,sabrina appeared1 other islands have appeared and disappeared1 at times long before #ahaa2 that is1 during the year #afia1 as well as during #agbj4 ,another instance of a submarine island is ,graham's ,island1 that was thrown up in #ahca1 in the ,mediterranean ,sea1 between the west coast of ,sicily and the nearest part of ,africa1 on which ancient ,carthage was situated4 ,the part of the sea where the island was thrown up had previously a depth of #fjj feet4 ,the general appearance of ,graham's ,island is represented in ,fig4 #bb4 ,graham's ,island was formed by accumulations of loose scoria and cinders1 together with blocks of lava and fragments of limestone4 ,it reached a height of #bjj feet above the water1 but only remained above the surface for a few months1 when it was washed away1 leaving a submarine bank some twelve miles in width1 that was covered by water of about #aej feet1 but which1 however1 increased rapidly in depth towards the edge until depths of from #a1bjj to #b1jjj feet were reached4 ,illustration3 ,,fig4 #bb4 ,,graham',s ,,island--,a ,,recent ,,volcanic ,,island ,according to ,lyell1 on the #bhth of ,june1 #ahca1 before ,graham's ,island appeared1 a ship passing over this portion of the sea felt severe earthquake shocks4 ,on ,july #ajth of the same year1 the captain of a vessel from ,sicily reported that as he passed near this part of the ,mediterranean1 a column of water1 #hjj yards in circumference1 was seen to rise from the sea to a height of sixty feet1 and that afterwards a column of steam rising to a height of #a1hjj feet was seen in the same place4 ,on again passing the same region on ,july #ahth1 this captain found a small island about twelve feet in height1 with a crater in its centre1 that was throwing out volcanic materials1 together with immense masses of vapor4 ,the island thus formed grew rapidly1 both in size and height4 ,when visited at the end of ,july1 it had attained a height of from fifty to ninety feet1 and was three-quarters of a mile in circumference4 ,by ,august #dth1 it had reached a height of #bjj feet1 and was then some three miles in circumference4 ,from this time1 however1 the island began to decrease in size1 as the waves began to wash it away4 ,by ,august #beth1 it was only two miles in circumference4 ,on ,september #c;d1 it had decreased to three-fifths of a mile in circumference1 and continued to decrease until it entirely disappeared1 so that in the year #ahcb1 there were1 according to measurements1 some #aej feet of water over its former site4 ,the ,mediterranean ,sea between ,sicily and ,greece is also especially liable to submarine activity4 ,new islands appear and disappear so frequently that in this region they are almost regarded as common phenomena4 ,there are many other parts of the ocean where submarine volcanic eruptions are common4 ,this is especially the case in the narrowest part of the ,atlantic ,ocean between ,africa and ,south ,america4 ,here there is a region situated partly above the equator1 though for the greater part south of the equator1 frequently visited by submarine eruptions1 that are accompanied by earthquakes1 by the agitation of the water1 by the appearance of floating masses of ashes and scori1 as well as by columns of steam or smoke4 ,floating masses of ashes and scori sometimes occur so thick as to retard the progress of vessels4 ,but what forms1 perhaps1 one of the best instances of a large island formed by submarine eruptions during historical times1 is ,bogosloff ,island in ,behring ,sea1 some forty miles west of ,unalaska ,island4 ,this island1 the position of which is seen on the accompanying map1 is known to the ,russians as ,ioanna ,bogoslova1 or ,st4 ,john the ,theologian4 ,it is situated in lat4 #ec #eh' ,n41 long4 #afh west4 ,it is said that during the year #agie1 some of the natives of ,unalaska ,island saw what they thought was a fog in the neighborhood of a small rock1 which they had known for a long time to project above the sea in these waters4 ,this rock was marked on some ,russian chart dated #agfh-fi4 ,it was seen by ,captain ,cooke1 in #aggh1 and was named by him ,ship ,rock4 ,but it was not a fog that the ,unalaskans had seen in the neighborhood of ,ship ,rock2 for1 to their great surprise1 the fog continued in sight although everywhere else the air was quite clear4 ,of course1 this was a great mystery to the people4 ,during the spring of #agif1 one of them1 who possessed either greater curiosity than the rest1 or greater courage1 or both1 visited the rock4 ,he returned1 telling the strange story that all the ocean around the rock was boiling1 and that the mist or fog was caused by the rising steam4 ,what was taking place was a submarine eruption4 ,during ,may1 #agif1 sufficient matter had been brought up from below to increase greatly the area of the small rock4 ,illustration3 ,,fig4 #bc4 ,,aleutian ,,islands ,during later years several attempts have been made to visit ,bogosloff ,island4 ,for example1 the island was visited during #ahgb and #ahgc1 when it was found to have increased in height to #hej feet4 ,but no appearance of any volcanic crater was to be seen4 ,during ,october1 #ahhc1 a great volcanic eruption occurred there4 ,considerable changes were produced in its shape1 as well as in the depth of the surrounding water4 ,during this eruption1 clouds of steam completely hid the island4 ,great quantities of ashes obscured the light of the sun4 ,after the eruption1 a new island was thrown up near the old one1 in a place where the water had previously been deep enough for the ready passage of ships4 ,the new island was about half a mile from the old one4 ,it was conical in form1 from #ejj to #hjj feet in height1 and about three-quarters of a mile in diameter4 ,the new island was visited in #ahhd by the ,u4 ,s4 ,revenue ,marine ,steamer ,corwin4 ,lieutenant ,cartwell1 who visited the island at this time1 described it as follows3 ,the sides of ,new ,bogosloff rise with a gentle slope to the crater4 ,the ascent at first appears easy1 but a thin layer of ashes1 formed into a crust by the action of rain and moisture1 is not strong enough to sustain a man's weight4 ,at every step my feet crushed through the outer covering and ,i sank at first ankle-deep and later on knee-deep into a soft1 almost impalpable dust which arose in clouds and nearly suffocated me4 ,as the summit was reached1 the heat of the ashes become almost unbearable1 and ,i was forced to continue the ascent by picking my way over rocks whose surfaces being exposed to the air1 were somewhat cooled and afforded a more secure foothold4 ,on all sides of the cone there are openings through which steam escaped with more or less energy4 ,i observed from some vents the steam was emitted at regular intervals1 while from others it issued with no perceptible intermission4 ,around each vent there was a thick deposit of sulphur1 which gave off suffocating vapors4 ,,chapter ,,xvi ,,distribution ,,of ,,the ,,earth',s ,,volcanoes ,having now considered at some length the principal volcanoes of the earth1 and endeavored to obtain some idea of the many wonders they exhibit1 especially as regards the vast quantities of material they bring from the inside of the earth1 as well as the great force with which they sometimes throw these materials out of their craters1 it will be well to point out where such volcanoes are to be found4 ,it may have seemed to you1 when you have carefully followed what has been said about the earth's volcanoes1 that they are to be found pretty nearly everywhere1 at least so far as latitude is concerned2 and in this supposition you are correct2 for there are volcanoes in the ,arctic ,ocean1 as in the volcanic island of ,jan ,mayen between ,iceland and ,spitzbergen1 there are ,mt4 ,erebus and ,mt4 ,terror in the ,antarctic ,ocean1 besides very numerous volcanoes in the ,atlantic1 ,pacific1 and ,indian ,oceans1 and their shores in both the temperate and the torrid zones4 ,there is1 however1 one thing that you have probably especially noticed and that is that volcanoes are seldom found at very great distances from the ocean1 except on some of its arms or seas1 such as the ,mediterranean ,sea4 ,i do not mean by this that all the earth's volcanoes are either situated directly on the coast of the continents or on islands1 since1 in such a large body as the earth1 a distance of a few hundred miles from the ocean is hardly to be regarded as being very far from it4 ,but it is true that all the earth's volcanoes are either situated on the coasts of the continents1 or on islands1 and1 moreover1 they are situated to a greater or less extent along lines1 which1 as we have already pointed out1 are believed to mark weak portions of the earth's crust that have been fissured or fractured4 ,in order that you may have some idea of this distribution1 ,i think it will be well to give you a number of interesting facts that have been pointed out by ,dana4 ,according to this authority1 there are something in the neighborhood of #cjj active volcanoes on the earth4 ,of these1 no less than five-sixths1 or #bej1 lie either on the borders of the ,pacific ,ocean1 or on some of its many islands4 ,thirty-nine either lie within or on the borders of the ,atlantic1 of which thirteen are in ,iceland1 or near the ,arctic ,circle1 three in the ,canaries1 seven in the ,mediterranean ,sea1 six in the ,lesser ,antilles1 and ten in the ,atlantic ,oceanic ,islands4 ,the ,indian ,ocean contains only a few active volcanoes4 ,there are1 however1 a much greater number of extinct volcanoes1 which may at any time again become active4 ,the following is the distribution of the earth's volcanoes as given by ,dana4 ,as you will see1 from an inspection of ,fig4 #bd1 all of the regions of volcanoes lie either on the borders of the continents1 or on islands in the oceans4 ,the districts are as follows3 #a4 ,scattered ,over the ,pacific ,ocean4--,this district includes the following active volcanoes2 i4 e41 the ,hawaiian ,islands1 nearly in mid-ocean1 almost directly below the ,tropic of ,cancer2 in the west central parts of the ,south ,pacific2 in the ,new ,hebrides2 in the ,friendly ,islands1 the ,tongan or ,new ,zealand ,islands1 in the ,santa ,cruz ,islands1 and in the ,ladrones4 ,illustration3 ,,fig4 #bd4 ,,map ,,of ,,the ,,world1 ,,showing ,,location ,,of ,,active ,,and ,,recently ,,extinct ,,volcanoes #b4 ,on the ,borders of the ,pacific4--,this district includes the volcanoes that extend from the southern part of ,south ,america at intervals along the ,andes ,mountain range4 ,of these there are thirty-two in ,chile1 seven or eight in ,bolivia and ,southern ,peru2 about twenty in the neighborhood of ,quito4 ,further north there are thirty-nine in ,central ,america1 and seven in ,mexico4 ,proceeding northwards through the ,united ,states1 there are a number of volcanic mountains1 generally extinct1 in portions of the ,sierra ,nevadas and ,cascade ,ranges4 ,probably a number of volcanic mountains exist in portions of ,canada lying between the northern boundaries of the ,united ,states and ,alaska1 and a number in ,alaska2 some twenty-one volcanic mountains in the ,aleutian ,islands2 some fifteen or twenty in ,kamtschatka2 thirteen in the ,kuriles2 some twenty-five or thirty in ,japan and the neighboring islands2 some fifteen or twenty in the ,philippines2 several along the northern coasts of ,new ,guinea2 a number in ,new ,zealand and south of ,cape ,horn2 the volcanoes of the ,deception ,island with its hot springs1 and also in the ,south ,shetlands #fb #cj' ,s4 #c4 ,in the ,indian ,ocean4--,on the western border of the ,indian ,ocean there are a few volcanoes in ,madagascar2 in the ,island of ,bourbon2 ,mauritius2 the ,comoro ,islands2 and in ,kerguelen ,land on the south4 ,there are also volcanoes on the western border of the ,indian ,ocean where the lofty peak of ,kilima ,ndjro1 #ah1jjj feet1 is volcanic4 #d4 ,over the ,seas that ,separate the ,northern and the ,southern ,continents and in their ,vicinity4--,this is an especially active region of volcanoes4 ,for the sake of convenience the continents of the world are sometimes divided into three pairs or double continents2 namely1 ,north and ,south ,america1 connected by the ,isthmus of ,panama2 ,europe and ,africa1 connected by the ,isthmus of ,suez2 and ,australia and ,asia1 completely separated by a sunken isthmus1 the summits of which form the ,sunda ,island chain4 ,in the first of these regions we have the very active group of the ,west ,indies1 where there are ten volcanic islands4 ,in the second pair of double continents we have the volcanoes of the ,mediterranean and ,red ,seas1 and their borders1 such as ,sicily1 ,vesuvius1 and other parts of ,italy1 ,spain1 ,germany1 the ,grecian ,archipelago1 ,asia ,minor1 and extending eastward through the ,caspian1 ,mt4 ,ararat1 ,demavend1 on the south shores of the ,caspian1 ,mt4 ,ararat1 and some few others along the borders of the ,red ,sea4 ,in the ,east ,indies we find the most intense centre of volcanic activity in the world4 ,here there are some #bjj volcanoes of which there are nearly fifty in ,java alone1 more than half of which are still active4 ,there are nearly as many volcanoes in ,sumatra1 and many in the small islands near ,borneo1 the ,philippines1 etc4 #e4 ,on the ,borders of the ,atlantic and ,elsewhere4--,it is an interesting fact that there are no volcanoes on the eastern borders of the ,atlantic north of the ,west ,indies ,island chain4 ,in the ,south ,atlantic the only volcano on the borders is one of the ,cameroons ,mountains4 ,in the ,atlantic ,ocean we have ,iceland1 the ,azores1 the ,canaries1 ,cape ,verde1 ,ascension1 ,st4 ,helena1 and ,tristan d',acunha4 ,this curious distribution of the volcanoes of the world near the oceanic waters appears to be dependent rather on the very early shapes of the continents and the ocean beds than on their present shapes4 ,,chapter ,,xvii ,,volcanoes ,,of ,,the ,,geological ,,past ,the question is often asked whether the volcanic eruptions of the geological past were not much more violent and destructive than the volcanoes of the present time4 ,now1 while this is a matter that properly belongs to the subject of geology1 and will be treated at greater length in the ,wonder ,book on ,geology1 yet a short mention should be made of it here4 ,it is the opinion of ,dana that while there have been volcanoes during the different geological ages1 yet volcanic activity has increased through the geological past until the age that immediately preceded the appearance of man on the earth4 ,he thinks there is no reason for believing that there were any very great volcanic eruptions during the earliest geological time known as the ,archic4 ,dana speaks as follows concerning this3 ,in this connection it is an instructive fact that in eastern ,north ,america1 at epochs when there was the greatest amount of friction and crushing 444 those of the making of the ,green ,mountains and the ,appalachians 444 no volcanoes were made1 and little took place in the way of eruptions through fissures4 ,on the other hand1 ,prestwich seems inclined to think that the absence of well-marked cones of volcanic material in the rock of the older geological ages is not to be regarded as proof that no eruptions then took place1 since the very great amount of erosion that occurred between that time and the ,tertiary ,age before the appearance of man1 would1 probably1 have completely obliterated any cones1 and even the volcanic materials would have undergone such changes as completely to alter their general character4 ,he agrees1 however1 with ,dana that1 probably1 the most violent and explosive volcanoes of the geological ages have been those of the ,tertiary ,age4 ,without1 however1 attempting anything more than a brief reference to the volcanoes of the geological past1 it may be said that many of the more important of the active volcanoes of the earth's present time were begun in the ,tertiary ,age4 ,mt4 ,etna1 ,vesuvius1 and ,mt4 ,hecla are believed to have commenced at this time4 ,there is an interesting region of geological volcanoes in the neighborhood of ,auvergne in ,central ,france4 ,here they occur in three separate groups that extend over a high granite platform from north to south for a distance of about #ajj miles1 and from twenty to eighty miles from east to west4 ,the eruptions began in the earlier portions of the ,tertiary ,age1 and continued down to the latter periods of prehistoric times4 ,some of these volcanic craters remain to-day almost as unaffected by erosion as if they had been formed but recently4 ,other regions of geological volcanoes are to be found in parts of ,spain near the foot of the ,pyrenees ,mountains1 in parts of ,italy and ,germany1 as well as in regions in the ,caucasus ,mountains4 ,in ,asia ,minor there exists a group of almost thirty extinct volcanoes in the neighborhood of the ,gulf of ,smyrna4 ,both ,little and ,great ,ararat contain volcanic cones3 that in the latter mountain was active during historical times4 ,there are also extensive volcanic districts in the ,taurus ,mountains4 ,in addition to these there are groups of extinct volcanoes in portions of ,central ,asia4 ,aden1 on the ,red ,sea1 is the centre of an extensive volcanic district4 ,indeed1 on both shores of the ,red ,sea there are a few volcanoes that are still active1 while in ,sinai1 and in the districts of the south1 there are several extinct craters4 ,but it is in the ,new ,world1 especially on the ,pacific coast of ,north ,america1 that volcanic activity was especially great during the geological past4 ,there is a district containing volcanic rocks that extends through various parts of western ,north ,america1 from ,new ,mexico and ,north ,california1 to ,oregon and ,british ,columbia4 ,this district has a width of from eighty to #bjj miles1 and a length of not quite #hjj miles4 ,this great area of nearly #aej1jjj square miles is covered with great sheets of volcanic rocks except where mountain ranges rise from them1 or where the rivers have cut deep valleys through them4 ,in portions of ,california and ,new ,mexico these plateaus rise to heights of from #h1jjj to #aj1jjj feet1 while in parts of ,colorado1 where they form huge dome-like mountains1 they reach a thickness of #ad1jjj feet4 ,in ,oregon the sheet of lava is #b1jjj feet thick1 and1 indeed1 in some places1 is estimated to have a depth of #g1jjj feet4 ,in the opinion of nearly all ,american geologists these great lava flows in western ,north ,america were not of the type known as crater eruptions1 but were what are called fissure eruptions4 ,some of them are believed to have occurred during geological times as early as the ,eocene4 ,prestwich1 however1 is of the opinion that the eruptions of the past in these portions of the world were not confined to fissure eruptions1 but that crater eruptions also occurred2 and that it was towards the close of the ,tertiary ,age that crater eruptions occurred with great lava flows4 ,indeed1 as we have seen1 in portions of ,utah and the neighborhood the remains of true craters can be found4 ,besides the above there are evidences of geological volcanoes of still older times4 ,in portions of ,deccan1 in southern ,hindostan1 there is an immense plateau formed of trap rock1 that extends from east to west for a distance of #djj miles1 and from north to south through from #gjj to #hjj miles4 ,this district1 with an area of almost #bjj1jjj square miles1 is covered with a vast lava sheet4 ,it was1 in the opinion of ,prestwich1 from whom many of the facts of the geological volcanic eruptions have been obtained1 probably still more extensive4 ,the plateau of ,deccan rises gradually from the east to the west1 where1 in some parts of the ,ghauts ,mountains1 it reaches a height of from #d1jjj to #e1jjj feet4 ,one of the greatest of these prehistoric volcanoes of ,scotland was a volcano in the ,isle of ,mull in the ,hebrides4 ,this volcano was probably nearly thirty miles across at its base1 and was from #aj1jjj to #ab1jjj feet high4 ,it is now only #c1agb feet in height4 ,according to ,judd the ,island of ,skye in ,inverness-shire is the remains of a volcano that was active in ,tertiary times1 probably many millions of years ago4 ,this volcano was very large1 probably about thirty miles across at its base1 with a height of perhaps as great as #ab1jjj or #ae1jjj feet4 ,now there are only left some granite and other similar rocks that form the ,red ,mountains and ,coolim ,hills of ,skye that reach about #c1jjj feet above the sea level4 ,there are many other parts of the world containing volcanoes that were active during the geological past4 ,the above1 however1 is as far as we can describe such volcanoes in this book4 ,,chapter ,,xviii ,,laplace',s ,,nebular ,,hypothesis ,la,place's nebular hypothesis is the name given to an ingenious hypothesis proposed by ,la,place1 a celebrated ,french astronomer1 in an endeavor to explain how the solar system has been evolved4 ,you will notice that this is called a hypothesis and not a theory4 ,the word hypothesis is properly applied to a more or less intelligent guess or assumption1 that has been made for the purpose of trying to find out in the cause of any natural phenomenon4 ,a theory is an expression of a physical truth based on natural laws and principles that have been independently established4 ,a theory1 therefore1 is much more complete than a hypothesis4 ,a hypothesis1 as ,silliman remarks1 bears the same relation to a theory or law1 that a scaffolding does to a completed building1 since it forms a convenient means for erecting the building4 ,la,place's work is properly called a hypothesis1 because it is not to be considered as any more than a means for enabling one intelligently to inquire into the probable manner in which the solar system has reached its present condition1 by gradual steps or stages during the almost inconceivable length of time since its creation4 ,before describing ,la,place's hypothesis it will be necessary to give you some ideas concerning what is known by astronomers as the solar system4 ,the solar system consists of the sun1 and the eight large bodies called planets that revolve around the sun4 ,it also includes a number of moons or satellites revolving around the planets1 a number of small bodies1 called planetoids or asteroids1 together with numerous comets and meteorites4 ,besides these there is probably a system of meteoric bodies that are believed to revolve around the sun1 and to produce1 by the reflection of the light from their surfaces1 what is known as the zodiacal light4 ,the principal bodies of the solar system are the planets4 ,these constitute eight large bodies named in their order from the sun1 beginning with the nearest3 ,mercury1 ,venus1 ,earth1 ,mars1 ,jupiter1 ,saturn1 ,uranus1 and ,neptune4 ,the last four planets1 ,jupiter1 ,saturn1 ,uranus1 and ,neptune are much larger than the others1 and are therefore known as the major planets in order to distinguish them from ,mercury1 ,venus1 ,earth1 and ,mars1 which are called the minor planets4 ,you can remember the order in which the last three planets come by their initial letter1 ,s-aturn1 ,u-ranus1 and ,n-eptune1 spelling the word ,,sun1 around which they all revolve4 ,it may be interesting to state here that the ancients knew of seven only of these planets4 ,since1 as they asserted1 there were only seven days in the week1 and seven openings into the head2 i4 e41 two for the eyes1 two for the nostrils1 two for the ears1 and one for the mouth1 it was natural that there should be but seven planets4 ,during later years1 however1 an eighth planet was discovered and named ,neptune4 ,it would be interesting to explain to you how the position of this planet was reasoned out by mathematical calculations1 that is1 in other words1 how1 as a result of such calculations1 an astronomer was told that if he would point his telescope to a certain part of the heavens he would discover a new planet4 ,he did this and located the planet ,neptune4 ,however interesting this story may be it belongs properly to astronomy1 and will be described in full in the ,wonder ,book of ,astronomy4 ,in the opinion of some astronomers it is quite probable that a ninth planet will be found far beyond the orbit of ,neptune4 ,there may also be some additional planets discovered between ,mercury and the ,sun4 ,besides the eight known planets there exist1 somewhere between the orbits of ,mars and ,jupiter1 many smaller planets called asteroids1 or minor planets4 ,a long time ago it was pointed out by ,bode that a curious relation exists between the distances of the planets from the sun4 ,this relation or law is generally known1 after the name of the astronomer who first called attention to it1 as ,bode's ,law4 ,no reason has been discovered for this arrangement of the planets1 so that ,bode's ,law may be regarded as empirical4 ,it may1 however1 be mentioned here that the distances of all the planets from the sun agrees with the law very closely1 with the single exception of ,neptune1 which is quite at variance with the law4 ,it was noticed at an early date1 that a gap existed between ,mars and ,jupiter1 so that astronomers began to believe that there was probably a missing planet in that space1 and this belief was greatly strengthened when ,neptune was discovered in #agha4 ,without going any further into this story in this book1 it may be said that it is the general opinion of astronomers that the planetoids or asteroids were formed possibly from the fragments of the missing planet1 or1 more probably1 from the breaking up of some of the outer rings on the planet ,mars4 ,the distances of the planets from the central sun vary from the nearest planet1 ,mercury1 which is about #cf1jjj1jjj miles from the sun1 to the furthest1 or ,neptune1 which is #b1gff1jjj1jjj miles from the sun4 ,all the major planets have a single moon1 or more1 revolving around them4 ,for example1 ,jupiter has four moons2 ,uranus1 six2 ,saturn1 eight2 ,neptune1 one4 ,as to the minor planets1 ,mars has two moons2 and1 as far as is known1 neither ,mercury or ,venus has a moon4 ,our earth has one moon1 but1 as we shall afterwards see1 this is not to be regarded as a moon or satellite of the earth1 but rather as a twin planet to the earth4 ,la,place's nebular hypothesis was proposed by ,la,place during the year #agif4 ,while there are many objections that can be brought against it1 since it fails to account for all of the phenomena of the solar system1 yet it is a significant fact now1 in the year #aijg1 nearly a century and a quarter after the hypothesis was first announced1 that although modified in many respects1 there has not been any hypothesis proposed to entirely replace it4 ,while the nebular hypothesis of ,la,place is necessarily a matter that belongs to astronomy1 yet it will be advisable to consider it here1 since it explains the source of the original heat of both the earth and the moon1 which we believe is the true cause of volcanoes4 ,in his nebular hypothesis1 ,la,place assumes that all the materials of which the solar system is formed1 were originally scattered throughout space in the shape of an exceedingly rare form of matter known as nebulous matter4 ,he points out that if it be granted that this medium began to accumulate around a common centre1 so as to form a huge globe or sphere1 and if a motion of rotation on its axis from west to east were given to this sphere that1 on strictly mechanical principles1 a system of heavenly bodies corresponding to the solar system might have been evolved4 ,let us1 therefore1 try to understand how this might have been brought about4 ,the nebulous matter that ,la,place assumed originally constituted all the matter in the solar system1 was highly heated gaseous matter4 ,in other words1 it consisted of ordinary matter raised to a very high temperature2 ,la,place thought at a temperature very much hotter than that of the sun4 ,as this great mass of matter commenced to cool1 it began to collect around a centre and slowly rotate4 ,its contraction or shrinkage1 while cooling1 must have caused an increase in the speed with which it spun around or rotated on its axis4 ,at first it spun but sluggishly1 but as it cooled and began to shrink this rate of rotation began slowly to increase4 ,now you must bear in mind that the huge rotating mass1 as imagined by ,la,place1 was very many times larger than the size of our present sun4 ,indeed1 instead of having a diameter of only #hff1ejj miles1 its temperature was so high that the nebulous matter of which it was composed had expanded it so much that it extended far beyond the orbit of ,neptune1 or had a diameter twice as great as #b1gff1jjj1jjj miles4 ,as the huge mass continued to shrink or contract1 its rotation began to gradually increase until at last its centrifugal force was sufficiently great to cause it to bulge out at the equator1 so as at last to separate a ring of gaseous matter4 ,this ring was left behind by the sun1 as it continued cooling1 and formed the first planet that was born into the solar system4 ,the ring might have continued to revolve around the sun for a time1 and would1 of course1 revolve in the same direction as that in which the sun was rotating1 that is1 from west to east4 ,eventually1 however1 it broke up into smaller fragments1 that afterwards collected in a single body1 and1 assuming a globe-like shape of the planet1 formed the planet ,neptune4 ,necessarily1 too1 the planet so formed not only would revolve in its orbit from west to east in the same direction in which the sun was revolving on its axis1 but would also rotate or spin on its axis in the same direction4 ,after1 in this way1 throwing off the first planet1 the central sun continued to cool and grow smaller1 until the increase in the rate of its rotation was again such as to permit its centrifugal force to form a second ring around its equator1 which being left as the sun continued to contract1 gave rise to another planet1 or to ,uranus1 and so on until the four major planets and the four minor planets were born4 ,according to this hypothesis1 the planet that was first born was the planet that is farthest from the sun1 that is1 ,neptune1 and the planet last born must have been the nearest planet1 ,mercury4 ,but while all this planet forming was going on1 the separate planets also continued to shrink1 and1 therefore1 began to rotate more rapidly on their axes4 ,under the influence of the centrifugal force1 ring-like masses began to form around their equators1 and these masses left by the planet constituted their moons or satellites4 ,as you can see1 according to this hypothesis1 just as the planets would all revolve in their orbits from west to east1 and rotate on their axes in the same direction as the sun1 so1 too1 the moons or satellites of the planets would also rotate on their axes1 from east to west1 and revolve in their orbits in the same direction4 ,in order to show the extent to which ,la,place's nebular hypothesis explains the peculiarities of the solar system1 we must inquire what are the most important of these peculiarities4 ,we will take these from ,young's general book on ,astronomy1 from which most of the facts in this chapter have been condensed4 ,they are as follows3 ,the orbits of nearly all the planets and their satellites are nearly circular2 they are all in the same plane2 and all revolve in the same direction4 ,they are1 moreover1 with the single exception of ,neptune1 arranged at distances from the sun in accordance with ,bode's ,law4 ,all the planets increase in both directions1 towards and from the sun1 in density from ,saturn1 the least dense4 ,all the planets1 with the exception probably of ,uranus1 rotate in a plane that is nearly the same as the plane of the orbit in which they revolve4 ,moreover1 with the exception of probably both ,uranus and ,neptune1 all the planets rotate in the same direction as that in which they revolve4 ,the satellites revolve in orbits whose planes nearly coincide with the plane of the planets' rotation1 while the direction of the revolution of the satellites is the same as that in which their planets revolve4 ,finally1 the largest planets rotate most swiftly4 ,now1 ,la,place's nebular hypothesis explains nearly all of the above facts4 ,the following modifications of the hypothesis1 however1 are necessary4 ,let us briefly examine some of these modifications4 ,in the first place it can be shown that the original nebulous mass instead of being at a higher temperature than that of the sun was probably at a much lower temperature1 since the condensation of the gaseous matter must have increased the temperature4 ,instead1 therefore1 of the original nebulous mass being purely gaseous it was1 as ,young expressed it3 ,rather a cloud of ice cold meteoric dust than an incandescent gas or a fire mist4 ,or in other words1 the original nebulous mass from which the solar system was evolved1 consisted of finely divided particles of solid or liquid matter surrounded by an envelope of permanent gaseous matter4 ,a doubt1 too1 has been raised as regards the manner in which the planets were liberated from the central sun4 ,instead of separating in the form of a regular ring1 it has been thought that probably in most cases this separation assumed the shape of a lump4 ,it might1 however1 have occurred at times in the ring-like form as may be seen in the case of the planet ,saturn4 ,again1 instead of the outer rings being separated first1 and the others in regular order1 so that the outer planets are much the older1 it would seem possible1 or1 as ,young states1 even probable1 that several of the planets may be of the same or nearly the same age1 as they would be if more than one ring had been separated at one time1 or1 indeed1 several planets may have been formed from different zones of a single ring4 ,as you will see1 ,la,place's nebular hypothesis assumes that both sun and moon were in a highly heated condition when they were separated from the nebulous sun1 so that we can understand that the former molten condition of their interiors was due to the heat they originally possessed4 ,,chapter ,,xix ,,the ,,earth',s ,,heated ,,interior1 ,,the ,,cause ,,of ,,volcanoes ,as we have already seen1 the nebular hypothesis of ,la,place would seem to make it more than probable that the earth was originally in a highly heated condition1 and only reached its present state after long cooling4 ,while this cooling has gone on for probably millions upon millions of years both before and during the geological past1 yet in the opinion of perhaps the best geologists the interior of the earth is still very hot1 only the outer portions or crust having hardened by loss of heat4 ,that there is a very hot region somewhere inside the earth is evident1 since from some place or places below the surface there come out the immense streams of lava that1 continuing to flow at irregular intervals1 have at last built up such great masses of land as the island of ,hawaii1 the still greater island of ,iceland1 the even greater lava fields of the western ,united ,states1 and the great plateau of the ,deccan in southern ,hindustan4 ,it certainly must have required a great quantity of lava to build up an island like ,hawaii with its area of fully #dj1jjj square miles1 for the highest point on the summit of ,mt4 ,kea reaches #ac1hje feet above the level of the sea1 and1 moreover1 stands on the bed of the ,pacific ,ocean in water fully #ab1jjj feet deep4 ,but ,iceland is only one of many similar cases4 ,volcanoes are to be found in practically all parts of the earth1 not only in the equatorial regions1 where they are especially numerous1 but also in the frigid and temperate zones4 ,we must also remember the immense lava streams that are known to have come from the interior during the great fissure eruptions of the geological past4 ,when all these facts are taken into consideration1 it would certainly seem that there is only one source sufficiently great to supply this wonderful demand1 and that is the entire inside of the earth4 ,but entirely apart from volcanic phenomena there are other proofs that the entire interior of the earth is in a highly heated condition4 ,the differences of temperature caused by the sun during day and night do not affect the earth much below a depth of three feet1 while the differences of temperature between summer and winter do not extend much further below the surface than forty feet4 ,below these depths1 in all parts of the earth1 the temperature of the crust rises at a rate1 which1 although not uniform1 yet is not far from an increase of one degree of the ,fahrenheit thermometer scale for every fifty or sixty feet of descent4 ,if the above rate of increase continues uniform the temperature of the crust would be sufficiently hot to boil water at a distance of about #h1jjj feet below the surface1 while at a depth of about thirty miles the temperature would be sufficiently high to melt all known substances at ordinary conditions of atmospheric pressure2 that is1 to melt all known substances if they were subjected to such a temperature at the level of the sea4 ,in considering the above we must not lose sight of the fact that this increase in temperature with descent below the surface of the earth's crust occurs1 not only in places where there are volcanoes1 but over all parts of the earth1 thus seeming to point out that there is something hot below the surface which fills the entire inside of the earth4 ,it is true the greatest distance to which man has actually gone down through the earth's crust is but a few miles4 ,we do not1 therefore1 know by actual experience that the interior is anywhere in a fused condition1 yet the escape of lava or molten rocks in all latitudes1 and in the enormous quantities referred to above1 seems to show that the entire inside of the earth is at a temperature sufficiently high to melt all known substances under ordinary conditions4 ,it may be interesting in this connection to examine some of the proofs of this increase in temperature with descent below the surface4 ,the following figures are given by ,dana3 ,borings to great depths have been made in various parts of the earth1 both for artesian wells as well as for the shafts of mines4 ,after passing the line of invariable temperature1 the rate of increase for a total distance of #d1jjj feet below the surface is in the neighborhood of from one degree for fifty-five to sixty feet1 or an average of fifty-seven and a half feet for each degree of heat4 ,in the case of the deep artesian well bored at ,grenelle1 ,paris1 where a temperature of eighty-five degrees ,fahrenheit was reached at a distance of #b1jjj feet1 the rate of increase was somewhat more rapid1 being one degree ,fahrenheit for every sixty feet4 ,in a deep well bored in a salt mine at ,neusalzwerk1 ,prussia1 a depth of #b1bjj feet showed a temperature of ninety-one degrees ,fahrenheit at the bottom4 ,this was at the rate of one degree for every fifty feet of descent4 ,at ,schladenbach1 in ,prussia1 a well has been dug to the depth of #e1gce feet with a temperature of #acd ,f4 ,a boring at ,wheeling1 in ,west ,virginia1 reached a depth of #d1ejj feet1 #c1gjj feet below the level of the sea4 ,here the rate of increase of temperature in the upper half was one degree ,fahrenheit for every eighty feet1 and in the lower half of one degree for every sixty feet4 ,it must not be supposed because the rate of increase of temperature is not uniform that the argument of a highly heated interior is weakened4 ,on the contrary1 it would be very surprising if the rate continued uniform2 for it is evident that the conducting power of different materials in the earth's crust for heat must necessarily make a great difference in the rate at which heat should increase1 as we go farther down into the earth4 ,this is so important a matter that ,i will explain it at somewhat greater length4 ,let us suppose that instead of the highly heated interior of the earth1 we consider the simple case of a hot stove1 the doors or other openings into which are closed so that it is impossible to see the red hot coals inside4 ,now1 suppose holes were bored in the sides of this stove not deep enough to reach the red hot mass within1 and that tightly fitting rods or plugs all of the same length and thickness1 but of different kinds of materials such as wood1 earthenware1 glass1 iron1 copper1 silver1 and gold1 etc41 were so placed in the holes as to tightly fit them4 ,now1 under these circumstances the end of all the plugs would be at the same distance from the heated inside4 ,they would not1 however1 by any means show the same temperatures1 the metallic rods would be too hot to touch1 while the end of the piece of wood would hardly be hot enough to burn the hand when held against it4 ,the piece of glass and earthenware though less cool would be much less hot than the different rods of metals4 ,their temperatures would be necessarily affected by their conducting power for heat4 ,the wood1 the glass1 and the earthenware being poorer conductors than the metals would show much lower temperatures4 ,now1 the same thing is true with the different materials that constitute the rocks of the earth's crust4 ,some of these are much better conductors of heat than others1 so that the rate of increase of temperature with descent below the surface must necessarily vary with the kind of materials that form the crust of different parts of the earth4 ,you may1 therefore1 safely conclude that the entire interior of the earth is in a highly heated condition1 and that the source of this heat is to be traced to the heat the earth originally possessed when1 in accordance to the nebular hypothesis of ,la,place1 it was separated from the sun which gave birth to it1 that the present crust of the earth has been formed on the outside by the loss of a portion of this heat4 ,the rapidity with which a body cools1 depends1 among other things1 on the difference between its temperature and that of the medium in which it is placed4 ,the greater this difference of temperature the greater the rapidity of cooling4 ,careful measurements made by ,tait1 the ,english physicist1 show that our earth loses every year from each square foot of surface1 an amount of heat that would be able to raise the temperature of one pound of water from the melting point of ice to the boiling point of water1 or from #cb ,f4 to #bab ,f4 ,the rate of loss of heat1 must1 therefore1 have been much greater when the earth was more highly heated than it is now1 and will be much smaller than now many years from the present4 ,now1 let us suppose1 what nearly everyone acknowledges to be true1 that the earth was originally so hot as to be a molten globe1 and that while in this molten condition1 it began to revolve or move around the sun4 ,since the empty space through which the earth moves is very cold1 something in the neighborhood of #de below the zero of the ,fahrenheit thermometer scale1 the loss of heat would take place very rapidly and a thin crust of hardened materials would be formed on the outside4 ,now all the time the earth is cooling1 it is shrinking or growing smaller4 ,a very little thought will convince you that this cooling or shrinkage could not go on uninterruptedly2 for1 while the earth was cooling it was contracting1 or growing smaller1 and in this way a great pressure1 or as it is generally called in science1 a great stress was being produced4 ,every now and then this stress became so great that the crust of the earth was fractured or broken4 ,at first these fractures would not require a very great amount of stress or force1 since the crust of lava was then very thin4 ,after great periods of time1 however1 the crust grew thicker and thicker1 and the amount of force required to break it continually increased1 so that the fractures of the crust produced a greater disturbance4 ,whenever the earth's crust was fractured in this way the earth was shaken by what are called earthquakes1 while a part of the molten interior would run out or escape1 making volcanoes4 ,in the very early times neither the earthquakes or the volcanoes were as energetic as they were at later periods when the thickness of the earth's crust increased4 ,now1 having as we believe correctly come to the conclusion that the entire interior of the earth is in a highly heated condition1 the next question that arises is as to the present condition of this interior4 ,a long time ago it was believed that the interior of the earth is still melted1 and that a cooled portion or crust surrounds a great molten mass that fills all the inside2 that it is this mass which supplies the immense quantities of molten rock or lava that escape through the craters of volcanoes or through the fissures in the crust4 ,without going into this question thoroughly1 since it is a very difficult question to understand1 it will be sufficient to say that there are many reasons why it is impossible to believe that the interior is still melted4 ,you will understand that if the interior of the earth were melted like a huge central sea of fire that each volcano would necessarily affect all the others4 ,now1 as we have seen1 this is never the case1 so that this is one reason we cannot believe in the existence of a melted interior4 ,another reason we cannot believe in a molten interior is an astronomical consideration4 ,it can be shown that under the attraction of the sun and moon the earth could not possibly behave as it does if it were still liquid in the interior4 ,that1 on the contrary1 the behavior of the earth to the attraction of the sun and moon is such as to make it necessary for us to believe that it is as rigid throughout as would be a globe of steel of the same size4 ,i can easily understand that you find it very difficult to see how it can be believed that the interior of the earth is solid and yet at the same time be sufficiently hot to melt4 ,i can imagine hearing you ask if it is hot enough in the inside to melt any known materials1 why it is not melted4 ,the reason1 however1 is very simple when you come to think it over4 ,for a solid to fuse or become melted1 it is not only necessary for it to be heated to a temperature which is different for different substances1 but that at the same time it is heated it shall have plenty of room in which to expand or grow bigger4 ,in other words1 the temperature required to fuse any substance increases very rapidly with the pressure to which that substance is exposed4 ,now1 try to think of the pressure to which the materials that fill the inside of the earth are subjected at great distances below the surface4 ,this pressure is enormous1 not only by reason of the weight of the many miles of rocks that are pressing down1 but also by reason of the enormous stress or pressure caused by contraction or shrinkage4 ,when we say that the interior of the earth is hot enough to melt all known substances we mean hot enough to melt them if they could be brought from great depths to the level of the sea1 but not hot enough to melt them when subjected to the great pressure that exists in regions far below the surface of the earth4 ,briefly1 the condition of things is believed to be as follows3 ,the entire interior is filled with rock hot enough to melt at the level of the sea1 but under too great pressure to melt4 ,if this be granted1 as it is by perhaps the greatest number of men who are competent to judge1 the phenomena of earthquakes can be readily explained1 as can1 indeed1 the phenomena of those great movements whereby great changes of level take place in different parts of the earth4 ,now let us see how volcanoes can be explained on the assumption that the interior of the earth is hot enough to melt1 but remains solid only because there is no room for the heated mass to expand in4 ,such a heated interior as we have imagined1 must be constantly losing its heat and1 therefore1 shrinking4 ,every now and then this shrinkage must produce great fissures or cracks in the solid crust of the earth4 ,now should such cracks or fissures extend downwards to the heated interior1 there must result a decrease in the pressure4 ,the rocks would1 therefore1 begin to expand and would be forced by the great pressure to rise slowly in such cracks or fissures4 ,the further they rise the greater the relief of pressure1 until they at last assume a molten condition in which they are forced out through the craters of volcanoes as molten rocks or lava4 ,but it is not only volcanoes that seem to indicate a highly heated plastic condition as existing in the earth's interior4 ,as geologists well know1 there are to be found in the various strata of the earth places where great fissures have been made at various times during the geological past4 ,these fissures vary in width from a few inches to many hundreds of feet1 and are frequently scores of miles in length4 ,lava either flows out of them1 and covers adjoining sections of the country1 or simply rises in them and1 afterwards cooling1 forms dikes4 ,in many instances1 however1 the lava is forced in between more or less horizontal layers and in some cases has caused these layers to assume the shape of what geologists know as subtruderant mountains4 ,some of the eastern ranges of the ,rocky ,mountains have been formed in this manner4 ,we can1 therefore1 picture to ourselves the following as the manner of formation of an ordinary volcano4 ,a fissure is first formed in the solid crust of the earth1 extending downwards to the regions of great heat4 ,there is thus produced a relief of pressure1 so that at this point the highly heated rocks begin to be slowly forced up through the fissure4 ,as they rise higher and higher they become less solid and finally expand into fused masses that can flow out of the crater or opening in the earth's surface4 ,in this way a volcano is started4 ,but for this volcano to continue in eruption1 it is necessary that the conditions shall continue that force the molten rock upwards from great depths4 ,it is not enough for the lava to fill the crevice that exists upwards to the surface1 it must continue to be forced upwards until it escapes4 ,if it is permitted to remain in the fissure for any time1 it hardens1 and only great dikes are formed4 ,it would seem1 therefore1 that some other force must be called into action to keep the fissure open or1 in other words1 to prevent the chilling of the lava4 ,now1 this force is generally believed to be the expansive force of steam or the vapor of water4 ,as ,dana points out1 by far the greater part of the vapor which escapes from the craters of volcanoes consists of steam or the vapor of water4 ,indeed1 it can be shown that for every hundred parts of different vapors1 at least ninety-nine of such parts consist of water vapor4 ,it is for the greater part1 to the pressure of steam or water vapor that the escape of lava from the tube near the top of the crater is due4 ,of course1 the question arises as to where the water comes from that produces this steam4 ,there are three possible sources4 ,from the rains2 from leakage at the bed of the ocean2 and from vapors existing at great depths below the surface4 ,it is not probable that either rain water1 or water from the ocean1 penetrates through the earth's crust for distances much greater than a few thousand feet4 ,it is1 however1 very well known that in all parts of the earth1 except in desert regions1 whether they are near or far from the ocean1 the rocks are always found fully charged with water4 ,when1 therefore1 the slowly rising lava passes through the moist rocks that everywhere form the crust of the earth1 there must be formed in them great quantities of steam under very high pressure4 ,moreover1 many substances1 especially those forming lava1 possess the power of absorbing large quantities of steam and other gases4 ,therefore1 as the molten material reaches the moist rocks in the earth's crust1 it becomes highly charged with steam1 and as the lava rises towards the surface this steam expands4 ,where the lava is in a very fluid condition the steam quietly escapes1 as does the steam from the surface of boiling water4 ,but where the lava is viscous1 like tar or pitch1 great bubbles are formed1 which1 on their explosion1 throw the lava upwards for great distances into the air4 ,we can1 therefore1 account in this manner for both the non-explosive as well as the explosive type of volcanoes4 ,it must not be supposed1 however1 that it is the explosive power of steam which is the principal cause of the lava rising upwards from great depths4 ,this is caused by the great pressure or stress set up by the contraction of a cooling crust4 ,the pressure of this steam is added to this pressure which keeps the lava flowing upwards from great depths below4 ,the objection has sometimes been urged that it is impossible to believe the lava comes from a highly heated interior1 because1 as is well known1 lavas are of different types even when coming from the same volcano at different times of eruption4 ,while such an objection would have weight were it believed that the interior of the earth is still in a molten condition1 it loses its weight when one believes that the interior is solid4 ,it must1 however1 be acknowledged that the largest part of the interior of the earth would probably have the same chemical composition if it had ever been in a completely melted condition throughout4 ,i do not doubt you have already concluded that the reason the earth's volcanoes are practically limited to the borders of continents1 or to the shores of islands1 is the leakage of the ocean waters into the crust at these parts4 ,this was at one time believed by most geologists4 ,that sea water has much to do with such volcanoes as ,vesuvius there is no doubt1 but it is now generally recognized that it is not so much the present outlines of the earth1 or the present arrangement of its land and water areas1 that determines the distribution of the world's volcanoes4 ,it is rather believed that the location of the lines of fractures along which the earth's volcanoes are found were determined by conditions that occurred long before the earth assumed its present outlines4 ,but there is another explanation that has been suggested as regards the condition of the interior of the earth4 ,judd refers to this explanation as follows3 ,some physicists have asserted that a globe of liquid matter radiating its heat into space1 would tend to solidify both at the surface and the centre at the same time4 ,the consequence of this action would be the production of a sphere with a solid external shell and a solid central nucleus1 but with an interposed layer in a fluid or semi-fluid condition4 ,it has been pointed out that if we suppose the solidification to have gone so far as to have caused the partial union of the interior nucleus and the external shell1 we may conceive a condition of things in which the stability and rigidity is sufficient to satisfy both geologists and astronomers1 but that in still unsolidified pockets or reservoirs1 filled with liquefied rock1 between the nucleus and the shell1 we should have a competent cause for the production of the volcanic phenomena of the globe4 ,in this hypothesis1 however1 it is assumed that the cooling at the centre and the surface of the globe would go on at such rate that the reservoirs of liquid material would be left at a moderate depth from the surface1 so that easy communication could be opened between them and volcanic vents4 ,i must caution you1 however1 not to think that the above theory of volcanoes is accepted by all scientific men4 ,on the contrary1 there are many who believe that the earth is solid throughout because it has completely lost its original heat2 that it is only comparatively small areas that are to be found filled with molten or at least highly heated material4 ,but these opinions are held largely by those who have given their attention almost entirely to the phenomena of earthquakes1 or who base their reasonings on mathematical grounds only and have not sufficiently considered the phenomena of volcanoes4 ,since1 however1 they can be better understood after we have explained the phenomena of earthquakes1 we will defer their discussion to the last chapters of this book4 ,,chapter ,,xx ,,some ,,forms ,,of ,,lava ,in describing the wonders of volcanoes1 we must not fail to say something of the many remarkable forms that lava is capable of assuming4 ,all volcanic lavas contain large quantities of an acid substance known as silica1 or what is known better as quartz sand4 ,this material exists in lava combined chemically with various substances called bases1 the principal of which are alumina1 magnesia1 lime1 iron1 potash1 and soda4 ,although there are many kinds of lava1 yet all lavas can be arranged under three great classes according to the quantity of silica they contain4 ,acid lavas are those in which the quantity of silica is greatest4 ,in these lavas the silica1 which varies from #ff to #hj1 is combined with small quantities of lime or magnesia1 and comparatively large quantities of potash or soda4 ,some of the most important varieties of acid lavas are known as trachytes1 andesites1 rhyolites1 and obsidians4 ,basic lavas are those containing from #de to #ee of silica4 ,they are rich in lime and magnesia1 but poor in soda or potash4 ,some of the most important of basic lavas are the dolerites and basalts4 ,generally speaking1 basic lavas are of a darker color than acid lavas1 and fuse at much lower temperatures4 ,intermediate lavas are those containing silica in the proportion of from #ee to #ff4 ,while the temperature of liquid lava has not been very accurately determined1 yet1 since we know that molten lava is able to melt silver or copper1 its temperature must be somewhere between #b1ejj ,f4 and #c1jjj ,f41 the melting point varying with the chemical composition4 ,according to ,dana lavas can be divided into the following classes according to their fusibility2 i4 e41 lavas of easy fusibility1 such as basalts2 these lavas fuse at about #b1bej ,f42 lavas of medium fusibility1 including andesites2 these lavas fuse at about #b1ebj ,f42 lavas of difficult fusibility1 such as trachytes2 these lavas fuse at about #b1gjj ,f4 ,but what is1 perhaps1 most curious about lavas is that when the surface of a freshly broken piece of cold lava is carefully examined1 it is found to contain a number of small crystals of such mineral substances as quartz1 feldspar1 hornblende1 mica1 magnetite1 etc4 ,the best way to study the different forms of lava crystals is to prepare a thin transparent slice of hardened lava and then examine it with a good magnifying glass4 ,it will be found that the slice consists of a mass of a glass-like material through which the crystals are irregularly distributed1 not unlike the raisins and currants in a slice of not over rich plumcake4 ,when examined by a more powerful glass1 such as a microscope1 cloudy patches can be seen distributed irregularly through the glass-like mass4 ,when these patches are examined by a higher power of the microscope they are seen to consist of small solid particles of definite forms known as microliths and crystallites4 ,it has been shown by a careful study of these minute objects that they form the exceedingly small particles of which crystals are built up4 ,if we fuse a small quantity of lava and then let it slowly cool1 the glassy mass will be found to contain numerous crystallites4 ,on the other hand1 when fused lava is permitted to cool quickly1 it takes on the form of a black1 glass-like mass known as obsidian or volcanic glass1 a very common form of lava in some parts of the world4 ,in some lavas there are found larger crystals that appear to have been separated from the glassy mass1 under the great pressure that exists in the subterranean reservoirs at great depths below the volcanic crater1 and then floated to the surface surrounded by the glass-like material4 ,now when we examine these crystals with a higher power of the microscope1 we frequently find in them minute cavities containing a small quantity of liquid and a bubble of gas1 thus causing them to resemble small spirit levels4 ,the liquid in such cavities has been examined chemically and in most cases has been found to consist of water containing several salts in solution4 ,sometimes1 however1 the liquid consists of liquefied carbonic acid gas4 ,these wonderful things will be discussed at greater length in the ,wonder ,book of ,light4 ,when the mass of molten rock or lava that comes out of the crater of a volcano is thrown upwards in the air the condition it assumes by the time it falls back again to the earth depends on the height it reaches4 ,if this height is great the lava chills or hardens before reaching the earth1 and assumes various forms according to the size of the fragments4 ,the largest of these fragments are called cinders2 the finer particles volcanic dust2 while most of those of intermediate particles are known among other things as volcanic ashes4 ,we have already seen that when an explosive volcanic eruption occurs there is suddenly thrown out of the crater of the volcano a huge column of various substances that rises sometimes as high as #cj1jjj feet or even more4 ,the smaller fragments of lava are quickly cooled and form volcanic ashes1 sand1 cinders1 or dust4 ,these are rapidly spread out by the wind in the form of a black cloud1 that not only covers the mountain but reaches out over the surrounding country1 completely shutting off the light of the sun4 ,from this cloud particles of red hot ashes1 cinders1 sand1 etc41 begin to fall1 the largest particles near the crater of the volcano1 and the smaller particles at much greater distances4 ,in very powerful explosive volcanic eruptions such as ,krakatoa1 the finer dust may be carried to practically all parts of the world4 ,volcanic ashes consist of a fine1 light1 gray powder4 ,these particles take the name ashes from their resemblance to the ashes left after the burning of pieces of wood or coal in an open fire4 ,the name1 however1 as ,geicke points out1 is unfortunate1 since it is apt to lead one to suppose that volcanic ashes consist of some burned material4 ,such an idea is erroneous1 however1 since ashes do not consist of anything that is left after burning1 but merely of fine particles of molten rock that have hardened by cooling4 ,when in the shape of what is known as volcanic dust these particles are so exceedingly small that they can readily make their way through the smallest openings in a closed room just as does the finest dust in the rooms of our houses when they are shut up4 ,there are cases on record where people have been suffocated by the entrance of volcanic dust in closed rooms to which they have fled for safety during volcanic eruptions4 ,volcanic sand consists of the coarser particles of chilled lava that are partly round and partly angular4 ,they are of various sizes up to that of an ordinary pea4 ,volcanic sand is formed by the breaking up of the lava by the explosion of the vapors as they escape from the lava on relief from pressure4 ,volcanic dust when examined by the microscope is found to consist of very small particles that are more or less crystalline4 ,but besides the above there are larger fragments known as lapilli1 consisting of rounded or angular bits of lava varying in size from that of a pea to an ordinary black walnut4 ,these sometimes consist of solid fragments1 but are usually porous1 sometimes so much so that they readily float on water4 ,a curious form sometimes assumed by lava consists of what are called volcanic bombs4 ,these are formed during explosive eruptions1 when masses of liquid lava are hurled high up into the air4 ,during their flight they take on a rotary motion1 which tends to make them globular1 so that cooling1 while still revolving1 they assume the form of a more or less spherical mass4 ,at times1 however1 they are still sufficiently soft when they strike the earth to be flattened out in the form of flat cakes4 ,when of a spherical form these are very properly called volcanic bombs4 ,that volcanic bombs have actually been subjected to a spinning motion while in the air can sometimes be shown by the fact that masses of scori are frequently found in the interior with air cells largest at the centre of the bomb4 ,volcanic bombs are sometimes thrown from the crater to great distances4 ,during one of its recent eruptions1 ,cotopaxi threw out bombs that fell at a distance of nine miles from the crater4 ,according to ,dana another form of lava bombs is sometimes found on the slopes of the active volcanoes of ,hawaii1 where masses of lava acquire a ball-like shape while rolling down an inclination4 ,what are sometimes called volcanic bombs1 but which are more properly volcanic vesicles1 are produced by small fragments of lava which are thrown up in the air for only a moderate height and1 on cooling1 assume pear-like forms4 ,fig4 #be represents the appearance of volcanic vesicles4 ,the direction in which these vesicles moved through the air while in a molten state is indicated by their shape1 the blunt end being the end towards which the particles were projected4 ,illustration3 ,,fig4 #be4 ,,volcanic ,,vesicles ,from ,dana's ,manual of ,geology ,but by far the greater portion of the hardened lava2 i4 e41 the coarser1 heavier particles1 fall back on the mountain1 and collecting around the crater build up volcanic cones1 as already described in the case of mountains of the ,vesuvian type4 ,there are two different ways in which the melted lava is broken up into fine particles when it is thrown upwards from the crater of the volcano4 ,nearly all lava contains large quantities of steam that are shut up1 or occluded in the mass1 being prevented from escaping by reason of the pressure to which the lava is subjected4 ,the lava is released from this pressure as it is thrown out of the crater4 ,the steam or gases escape explosively and thus break the lava into fine liquid spray1 which rapidly hardens4 ,there is another way in which small particles of lava are formed4 ,sometimes large pieces of hardened lava are shot upwards into the air with a velocity as great as that with which a heavy projectile leaves the muzzle of a large gun4 ,these heavy particles striking against one another1 either while rising or falling1 are broken into smaller fragments4 ,sometimes1 indeed1 these fragments fall back again into the crater from which they are again violently thrown out1 and are again broken into smaller fragments either while rising or falling4 ,you will1 probably1 remember several instances of volcanic eruptions where masses of rock were thrown violently up into the air out of the crater4 ,these larger masses are known as volcanic blocks4 ,they probably consist of masses of hardened lava that have collected in the tube of the volcano during some of its periods of inactivity4 ,sometimes1 however1 they consist of fragments of rocks that are not of volcanic origin4 ,cases are on record where volcanic blocks have been thrown out of the craters in so great quantities as to cover the surface of many square miles of land with fragments hundreds of feet deep4 ,there is sometimes formed on the surface of a pool of lava as it collects in the craters of such volcanoes as ,mt4 ,loa or ,kilauea1 when the volcanoes are not in eruption1 a material resembling froth or scum4 ,the same thing sometimes occurs on the surface of some kinds of lava as it runs down the side of the mountain4 ,in this way a very light variety of highly cellular lava known as pumice stone is produced4 ,the action which thus takes place is not unlike that which occurs during the raising of a lot of the dough from which bread is made1 where the carbonic acid gas which is formed during the raising of the dough expands1 and produces the well-known open cellular structure of well-raised bread4 ,in the case of pumice stone1 however1 this raising goes on to such an extent that the mass consists often of less than #b of solid matter1 the remainder being a tangled mass of air4 ,illustration3 ,,the ,,lava ,,flow ,,of ,,the ,,crater ,,of ,,kilauea1 ,,hawaiian ,,islands ,from a ,stereograph1 ,copyright1 by ,underwood ,underwood ,fragments of lava that possess a cellular structure form what are known as scori4 ,the lightest of all kinds of scori is what is known as thread-lace scori4 ,here the thin walls consist of mere threads4 ,figs4 #bf and #bg represent the appearance of thread-lace scori from ,kilauea4 ,the separate threads are very fine1 being only from one-thirtieth to one-fortieth of an inch in thickness4 ,as can be seen1 this form of scori have six-sided or hexagonal shapes4 ,you can form some idea of the great lightness of such scori when you learn that they contain only #a4g of rocky material4 ,indeed1 they contain so little solid material that a layer of volcanic glass only one inch thick1 if blown out into scori1 would be able to produce a layer sixty inches thick4 ,illustration3 ,,fig4 #bf4 ,,thread-,,lace ,,scori ,,from ,,kilauea ,from ,dana's ,manual of ,geology ,another curious form sometimes assumed by lava1 especially in the case of ,kilauea1 is where the lava is spun out in the form of long silk-like hairs4 ,this is called by the natives ,pele's hair1 after the name of their goddess4 ,inasmuch as the origin of this form of lava was at one time generally attributed to the action of the wind in drawing out thread-like pieces from the jets of lava thrown upwards from the pool1 it will be interesting if its true cause is explained4 ,illustration3 ,,fig4 #bg4 ,,thread-,,lace ,,scori ,,from ,,kilauea ,from ,dana's ,manual of ,geology ,dutton1 in his report on the ,hawaiian volcanoes1 refers to the formation of ,pele's hair as follows3 ,the phenomenon of ,pele's hair is often spoken of in the school books1 and receives its name from this locality4 ,it has generally been explained as the result of the action of the wind upon minute threads of lava drawn out by the spurting up of boiling lava4 ,nothing of the sort was seen here1 and yet ,pele's hair was seen forming in great abundance4 ,whenever the surface of the liquid lava was exposed during the break-up the air above the lake was filled with these cobwebs1 but there was no spurting or apparent boiling on the exposed surface4 ,the explanation of the phenomenon which ,i would offer is as follows3 ,liquid lava coming up from the depths always contains more or less water1 which it gives off slowly and by degrees1 in much the same way as champagne gives off carbonic acid when the bottle is uncorked4 ,water-vapor is held in the liquid lava by some affinity similar to chemical affinity1 and though it escapes ultimately1 yet it is surrendered by the lava with reluctance so long as the lava remains liquid4 ,but when the lava solidifies the water is expelled much more energetically1 and the water-vapor separates in the form of minute vesicles4 ,since the congelation of all siliceous compounds is a passage free from a liquid condition through an intermediate state of viscosity to final solidity1 the walls of these vesicles are capable of being drawn out as in the case of glass4 ,the commotion set up by the descending crust produces eddies and numberless currents in the surface of the lava4 ,these vesicles are drawn out on the surface of the current with exceeding tenuity1 producing myriads of minute filaments1 and the air1 agitated by the intense heat at the surface of the pool1 readily lifts them and wafts them away4 ,it forms almost wholly at the time of the break-up4 ,the air is then full of it4 ,yet ,i saw no spouting or sputtering1 but only the eddying of the lava like water in the wake of a ship4 ,the country to the leeward of ,kilauea shows an abundance of ,pele's hair1 and it may be gathered by the barrelful4 ,a bunch of it is much like finely shredded asbestos4 ,you have probably often seen the beautiful frost pictures that collect on the panes of glass in a room where the ventilation has been neglected4 ,these pictures consist of groupings of ice crystals that collect on the surface of the windows1 when the moist vapor-laden air in the room is chilled by contact with their cold surfaces4 ,now the crystals formed in cooling lavas are sometimes grouped in forms closely resembling frost pictures4 ,a few of such forms are represented in ,figs4 #bh and #bi in lava from ,mt4 ,loa and ,mt4 ,kea4 ,illustration3 ,,fig4 #bh4 ,,frost-,,like ,,lava ,,crystals ,from ,dana's ,manual of ,geology ,illustration3 ,,fig4 #bi4 ,,frost-,,like ,,lava ,,crystals ,from ,dana's ,manual of ,geology ,certain varieties of lava1 especially that which is found in dikes1 form cool1 beautiful columns called basaltic columns4 ,they are due to the contraction that occurs on the cooling of the material4 ,instances of basaltic columns are seen in the ,giant's ,causeway1 on the northern coast of ,ireland1 as well as in the ,isle of ,cyclops on the coast of ,italy4 ,the general appearance of the latter is represented in ,fig4 #cj4 ,illustration3 ,,fig4 #cj4 ,,basaltic ,,columns1 ,,isle ,,of ,,cyclops1 ,,italy ,it is a curious fact that the entire mass of basalt does not generally take the columnous form but only certain layers which terminate suddenly above and below at structureless masses of basalt1 as shown in ,fig4 #ca4 ,these columns1 however1 are always found at right angles to the cooling surfaces as seen in the figures4 ,they may1 therefore1 be inclined at all angles to the horizon4 ,illustration3 ,,fig4 #ca4 ,,columnar ,,and ,,non-,,columnar ,,basalt ,when molten lava is only thrown up a short distance into the air from a crater it is still partially molten when on falling it again reaches the earth1 and therefore clings to any surface on which it falls4 ,there are thus built up curious cones known as driblet cones1 in which the separate drops covering the sides of the cone can be distinctly traced4 ,driblet cones are represented in ,figs4 #cb and #cc4 ,here1 as can be seen1 the separate drops can be readily traced as they run down a short distance before cooling4 ,illustration3 ,,figs4 #cb1 #cc4 ,,driblet ,,cones ,from ,dana's ,manual of ,geology ,we have already referred briefly to the lava caves or grottoes1 that are formed in some of the lava streams issuing from ,vesuvius1 ,etna1 or ,hawaii4 ,these caves consist either of a number of communicating huge bubbles1 or of the tunnels that are formed in the lava by the hardening of the outside of the lava streams as they flow down the sides of the mountain1 and towards the close of the eruption are afterwards emptied by the molten lava within continuing to flow to a lower level before solidifying4 ,now1 in the interior of these caves1 there are often found on the walls1 as well as on the portions of the floors of the caves1 immediately below them1 curious pendants1 like icicles1 or1 more correctly1 like the stalactites of limestone that are seen hanging to the walls of caves in limestone districts1 where they are formed as follows3 as the rain water sinks through limestone strata it dissolves some of the lime1 when1 slowly falling1 drop after drop1 from the roofs of the caverns1 small particles of lime are deposited on the roof1 and in this manner a pendant of limestone is formed4 ,the water that falls to the floor of the causeway immediately below1 also builds up a dome-like hillock called a stalagmite4 ,in due time the pillar reaches downwards1 and the opposite hillock upwards until the two meet1 thus forming great natural pillars that appear to hold up the roof of the vast cave in which they have been slowly formed4 ,a number of lava stalactites are represented in ,fig4 #cd4 ,illustration3 ,,fig4 #cd4 ,,lava ,,stalactites ,from ,dana's ,manual of ,geology ,now1 in a similar manner these lava stalactites1 formed in the lava caves or grottoes1 are caused by the stream as it escapes from the walls of the caves depositing on them stalactites of various lava minerals it has dissolved as it slowly passed through them4 ,but the most important of all volcanic products is volcanic dust4 ,this1 as we have seen1 is so light that it remains longest in the air1 and is often carried by the winds to great distances from the volcano from which it escaped4 ,it may interest you to know that some of the most fruitful of the great wheat fields of the western parts of the ,united ,states owe their extraordinary fertility to immense deposits of volcanic dust that have been thrown out from some of the great volcanoes of the geological past1 now found in an extinct condition in these parts of the ,united ,states4 ,according to ,russell1 immense deposits of volcanic dust are spread over vast areas in ,montana1 ,southern ,dakota1 ,nebraska1 and ,kansas1 as well as over parts of ,oregon1 and ,washington1 and1 indeed1 over large areas of southwestern ,canada and ,alaska4 ,it is practically certain that many of the eruptions producing this dust occurred within historic times4 ,there must1 therefore1 have been many times in these parts of our country when the dense ash clouds hiding the sun turned the day into night and destroyed the forests and other vegetation by showers of red hot ashes4 ,there were produced1 too1 the same great dread1 and possibly loss of life as common during historical eruptions4 ,it is pleasing1 however1 to think that while these great catastrophes brought suffering and dread to the people who then lived on the earth1 they were1 nevertheless1 but the forerunners of those fruitful fields that at a much later age were to bless the people who afterwards lived on them4 ,,chapter ,,xxi ,,mud ,,volcanoes ,,and ,,hot ,,springs ,mud volcanoes are the more or less conical hillocks from which1 under certain conditions1 mud is thrown out through the crust of the earth4 ,geikie defines mud volcanoes as follows3 ,conical hills formed by the accumulation of fine and usually saline 7salty7 mud1 which1 with various gases1 is continuously or intermittently given out from the orifice or crater in the centre4 ,they occur in groups1 each hillock being sometimes less than a yard in height1 but ranging up to elevations of #ajj feet or more4 ,like true volcanoes1 they have their periods of repose1 when either no discharge takes place at all1 or mud oozes out tranquilly from the crater1 and their periods of activity1 when large volumes of gas1 and sometimes columns of flame1 rush out with considerable violence and explosion1 and throw up mud and stones to a height of several hundred feet4 ,there are two kinds of mud volcanoes3 those in which the mud is thrown out by the action of different kinds of gases1 and those in which the mud is thrown out by the action of steam4 ,mud volcanoes may or not be volcanic phenomena4 ,those which occur in the neighborhood of volcanoes whether active1 dormant1 or extinct1 are probably of volcanic origin4 ,there are others1 however1 which occur in regions far removed from volcanoes4 ,these are probably due not to volcanoes1 but to chemical action and the eruptions are caused by the action of gases4 ,the gases producing these eruptions are either carbonic acid gas 7the gas that is given off from soda water72 carburetted hydrogen 7the gas that is sometimes seen escaping from the bottom of marshy ground72 sulphuretted hydrogen 7a gas that is given off from rotten or decomposing eggs1 and possessing the characteristic odor of decayed eggs7 and nitrogen gas derived from the atmosphere4 ,in mud volcanoes of the gaseous type the mud is generally cold1 and the water salty4 ,in this latter case the mud volcanoes are also called salses4 ,daubeny has pointed out that the mud volcanoes of this class that occur in the neighborhood of ,sicily are due to the slow burning or oxidation of beds of sulphur4 ,mud volcanoes which eject hot mud by the force of eruption of steam1 which occur in volcanic districts1 are of volcanic origin4 ,they are caused by the passage of hot water and steam through beds of volcanic rock such as tufa1 or hardened volcanic mud and other volcanic products4 ,the hot water or steam raises the temperature of the mud through which it passes to the boiling point4 ,as ,dana remarks1 the mud varies in consistency from very liquid muddy water to a thick mass like boiling soap1 or in some cases like masses of mud or paint1 and1 in still other cases1 to material like soft mortar1 the consistency of the mud varying with the dryness of the season4 ,there are three regions where mud volcanoes are especially common4 ,one of the best known is in the ,yellowstone ,national ,park1 four miles north of ,yellowstone ,lake1 and six miles from ,crater ,hill4 ,some of these mud volcanoes have circular craters about ten feet in depth around which they have built mounds1 the rims of which are several feet above the general level4 ,there are well-known regions of mud volcanoes in different parts of ,iceland4 ,here1 according to ,lyell1 they occur in many of the valleys where sulphur vapor and steam bursts from fissures in the ground with a loud hissing noise4 ,in these regions there are pools of boiling water filled with a bluish black clay-like paste1 that is kept violently boiling4 ,huge bubbles1 fifteen feet or more in diameter1 rise from the surface of the boiling mass4 ,the volcanoes pile up the mud around the sides of their craters or basins4 ,another part of the world where mud volcanoes are especially numerous is on the western shores of the ,caspian ,sea at a place called ,baku4 ,these are of the gaseous type and are attended by flames that blaze up to great heights often for several hours4 ,these flames are due to the presence of natural gas and petroleum vapor that pass out through the water4 ,large quantities of mud are thrown out from the craters of these mud volcanoes4 ,there are also many mud volcanoes in a district in ,india about #abj miles northwest of ,cutch near the mouth of the ,indus4 ,in this region the cone built up around the crater is sometimes as high as #djj feet4 ,the following description of mud volcanoes on ,java is quoted from ,daubeny's book on volcanoes4 ,it would appear likewise from ,dr4 ,horsfield's description1 that ,java exhibits phenomena of a similar kind to those noticed in ,sicily and at the foot of the ,apennines1 and there known under the name of ',salses4' ,in the calcareous district 7which ,i suspect to belong to the same class of formations as the blue clay and tertiary limestone of ,sicily7 occur a number of hot springs1 containing in solution a large quantity of calcareous earth1 which incrusts the surface of the ground near it4 ,of these1 some are much mixed with petroleum1 and others highly saline4 ,the latter are dispersed through a district of country consisting of limestone1 several miles in circumference4 ,they are of considerable number1 and force themselves upwards through apertures in the rocks with some violence and ebullition4 ,the waters are strongly impregnated with muriate of soda1 and yield upon evaporation very good salt for culinary purposes 7not less than #bjj tons in the year74 ,about the centre of this limestone district is found an extraordinary volcanic phenomenon4 ,on approaching the spot from a distance1 it is first discovered by a large volume of smoke rising and disappearing at intervals of a few seconds1 resembling the vapors arising from a violent surf1 whilst a dull noise is heard like that of distant thunder4 ,having advanced so near that the vision was no longer impeded by the smoke1 a large hemispherical mass was observed1 consisting of black earth mixed with water1 about sixteen feet in diameter1 rising to the height of twenty or thirty feet in a perfectly regular manner1 and1 as it were1 pushed up by a force beneath1 which suddenly exploded with a dull noise1 and scattered about a volume of black mud in every direction4 ,after an interval of two or three1 or sometimes four or five seconds1 the hemispherical body of mud or earth rose and exploded again4 ,in the same manner this volcanic ebullition goes on without interruption1 throwing up a globular mass of mud1 and dispersing it with violence through the neighboring places4 ,the spot where the ebullition occurs is nearly circular and perfectly level2 it is covered with only the earthy particles impregnated with salt water1 which are thrown up from below2 its circumference may be estimated at about half an ,english mile4 ,in order to conduct the salt water to the circumference1 small passages or gutters are made in the loose muddy earth1 which lead it to the borders1 where it is collected in holes dug in the ground for the purpose of evaporation4 ,a strong1 pungent1 sulphurous smell1 somewhat resembling that of earth-oil 7naphtha71 is perceived on standing near the site of the explosion1 and the mud recently thrown up possesses a degree of heat greater than that of the surrounding atmosphere4 ,during the rainy season these explosions are more violent1 the mud is thrown up much higher1 and the noise is heard at a greater distance4 ,this volcanic phenomenon is situated near the centre of the large plain1 which interrupts the great series of volcanoes1 and owes its origin to the same general cause as that of the numerous eruptions met with in this island4 ,there are1 in many parts of the world1 springs1 whose waters issue from their reservoirs at temperatures either at or near the boiling point of water4 ,these are called hot or thermal springs4 ,hot springs are found both in volcanic regions1 as well as in regions where there are no volcanoes1 but where there are lines of deep fissures or faults4 ,according to ,dana1 in both of these classes1 the cause is to be traced to heat of volcanic or deep subterranean origin4 ,hot springs are also found in regions where there are no volcanoes4 ,in these cases the heat is due to the gradual oxidation of various sulphide ores1 or to some other chemical action4 ,the waters of hot or thermal springs almost always contain various mineral substances in solution4 ,all spring water contains some little dissolved mineral matter1 but in hot springs the quantity of this matter is greater than in cold springs1 because hot water can dissolve mineral substances much better than can cold water4 ,it might surprise you to hear that one of the commonest substances that is found in solution in the waters of many hot springs is silica2 for silica is practically sand1 and sand does not easily dissolve in water as does sugar4 ,the very hot water1 however1 which comes from the hot spring1 whose temperature below the earth's surface is very much higher than it is when it comes out of the spring1 possesses the power of readily dissolving silica from the rocks over which it flows4 ,when the waters of such springs reach the surface the silica is deposited in a solid condition around the outlets of the springs4 ,in this way there are built up craters or mounds1 or1 more correctly1 crater-shaped basins4 ,sometimes the hot water contains calcareous substances dissolved in it1 the solution being caused not only by reason of the hot water1 but also by means of the carbonic gas it contains4 ,when this water flows from the springs1 it builds up the same crater-shaped mounds1 only in this case the mounds are of lime instead of silica4 ,there are peculiar kinds of hot springs called geysers1 that possess the power of throwing huge streams of water up into the air at more or less regular intervals4 ,the word geyser is an ,icelandic word meaning to rage1 or snort1 or gush1 the name being given by reason of the manner in which the waters rush violently out during an eruption4 ,as ,dana points out1 when the water in a basin of a hot spring merely boils1 whether this boiling is nearly continuous1 or the water is alternately boiling and quiet1 the spring is called a hot or thermal spring1 but where the water is thrown violently out at more or less regular intervals1 it is called a geyser4 ,the cause of the eruption of a geyser was discovered by ,professor ,bunsen1 the celebrated ,german chemist1 after a careful study of the geyser regions in ,iceland4 ,the waters of geysers contain large quantities of either silica or lime in solution4 ,bunsen traced the cause of these curious eruptions to be the manner in which the hot springs pile up cones of silica or limestone around their mouths4 ,the water of a geyser generally issues from the top of a more or less conical hillock1 reaching the surface through a funnel-shaped tube4 ,both the tube and the basin are covered with a smooth coating of silica or limestone4 ,in the case of the ,great ,geyser in ,iceland1 the basin is over fifty feet high and seventy-five feet deep4 ,both the tube and the basin have been slowly deposited by the hot water of the geyser4 ,it is only when the tube of a geyser has reached a certain depth that the geyser is able to erupt4 ,moreover1 as soon as this tube passes a certain depth the geyser can no longer erupt and forever afterwards becomes an ordinary hot spring4 ,there are1 therefore1 to be found in most geyser regions1 a number of what might be called young geysers or merely hot springs1 that are not yet deep enough to erupt2 others that have just commenced eruption1 others that have reached their prime1 while others that1 old and decrepit1 have again merely become hot springs4 ,let us now try to understand the cause of the eruption of a geyser4 ,bunsen's explanation1 which is now generally accepted1 is as follows3 ,the heat of the volcanic strata through which the tube of the geyser extends1 gradually raises the temperature of the water that fills the geyser tube4 ,since the boiling point of a liquid increases with the pressure to which it is subjected1 far down in the tube of a geyser1 the pressure arising from the weight of the water above it is sufficiently great to prevent the water from beginning to boil until it reaches a temperature far higher than that at which it would boil in the upper parts of the tube4 ,suppose now1 when the water in the funnel-shaped tube is nearly filled to the top1 the water at last grows hot enough to begin boiling at some point near the middle of the tube4 ,the pressure of the steam driven off from this portion of the water raises the column of water above it in the tube and begins to empty it out of the top of the geyser4 ,all the water below this point being thus suddenly relieved of its pressure1 and being now much hotter than is necessary to boil the water at that decreased pressure1 suddenly flashes into steam1 and violently shoots out all the water above it to a height that in some cases may be as great as #ajj to #bjj feet4 ,the steam causes this eruption1 then rushes out with a roar1 and the geyser eruption is over4 ,professor ,tyndall in his charming book entitled ,heat as a ,mode of ,motion speaks as follows concerning ,professor ,bunsen's discovery3 ,previous to an eruption1 both the tube and basin are filled with hot water2 detonations which shake the ground1 are heard at intervals1 and each is succeeded by a violent agitation of the water in the basin4 ,the water in the pipe is lifted up so as to form an eminence in the middle of the basin1 and an overflow is the consequence4 ,these detonations are evidently due to the production of steam in the ducts which feed the geyser tube1 which steam escaping into the cooler water of the tube is there suddenly condensed1 and produces the explosions4 ,professor ,bunsen succeeded in determining the temperature of the geyser tube1 from top to bottom1 a few minutes before a great eruption2 and these observations revealed the extraordinary fact that at no part of the tube did the water reach its boiling point4 ,in the sketch not reproduced ,i have given on one side the temperatures actually observed1 and on the other side the temperatures at which water would boil1 taking into account both the pressure of the atmosphere and the pressure of the superincumbent column of water4 ,the nearest approach to the boiling point is at ,a1 a height of #cj feet from the bottom2 but even here the water is #b ,c41 or more than #c-a_/b ,f41 below the temperature at which it could boil4 ,how then is it possible that an eruption could occur under such circumstances8 ,fix your attention upon the water at the point ,a1 where the temperature is within #b ,c4 of the boiling point4 ,call to mind the lifting of the column when the detonations are heard4 ,let us suppose that by the entrance of steam from the ducts near the bottom of the tube1 the geyser column is elevated six feet1 a height quite within the limits of actual observation2 the water at ,a is thereby transferred to ,b4 ,its boiling point at ,a is #abc4h1 and its actual temperature #aba4h2 but at ,b its boiling point is only #abj4h1 hence1 when transferred from ,a to ,b the heat which it possesses is in excess of that necessary to make it boil4 ,this excess of heat is instantly applied to the generation of steam3 the column is thus lifted higher1 and the water below is further relieved4 ,more steam is generated2 from the middle downwards the mass suddenly bursts into ebullition1 the water above1 mixed with steam clouds1 is projected into the atmosphere1 and we have the geyser eruption in all its grandeur4 ,by its contact with the air the water is cooled1 falls back into the basin1 partially refills the tube1 in which it gradually rises1 and finally fills the basin as before4 ,detonations are heard at intervals1 and risings of the water in the basin4 ,these are so many futile attempts at an eruption1 for not until the water in the tube comes sufficiently near its boiling temperature1 to make the lifting of the column effective1 can we have a true eruption4 ,the principal geyser regions of the world are in ,iceland1 in ,new ,zealand1 and in the ,yellowstone ,national ,park in the ,united ,states4 ,there are several geyser regions in ,iceland4 ,the best known lies in the neighborhood of ,mt4 ,hecla4 ,here is a great geyser that shoots up a column of water to a height of about #ajj feet every thirty hours4 ,fig4 #ce represents the appearance of the crater of the great geyser in ,iceland4 ,illustration3 ,,fig4 #ce4 ,,crater ,,of ,,the ,,great ,,geyser ,,of ,,iceland ,it is a well-known fact that in geyser regions generally1 the throwing of stones or other materials into the tube will frequently hasten an eruption4 ,this is probably due to the fact that the throwing in of these things results in the raising of the water in the tube1 thus hastening the eruption4 ,the ,new ,zealand region is in the neighborhood of ,lake ,rotomahama in the northern island4 ,the geyser region in the ,yellowstone ,park is by far the most interesting of all geyser regions4 ,this region is situated principally around ,fire-,hole ,fork of the ,madison1 and near ,shoshone ,lake at the head of ,lake ,fork of the ,snake ,river4 ,there are many geysers in this region1 as well as simple hot springs4 ,the temperature of their waters varies from between #afj and #bjj ,f4 to the boiling point of water at this elevation4 ,as you are probably aware1 water boils at the temperature of #bab ,f4 only under the condition of the ordinary atmospheric pressure that exists at the level of the sea4 ,at higher elevations1 such as on the slopes of mountains1 or on high plateaus1 water boils at a lower temperature4 ,the height of the country in which the ,yellowstone ,park is situated is so great that the water boils at temperatures of from #aih to #aii ,f4 ,the conical hillock of geyser cones from which the waters flow assume various shapes1 two of which are shown in ,figs4 #cf and #cg4 ,illustration3 ,,fig4 #cf4 ,,giant ,,geyser ,from ,dana's ,manual of ,geology ,illustration3 ,,fig4 #cg4 ,,bee ,,hive ,from ,dana's ,manual of ,geology ,that shown in ,fig4 #cf represents the shape of the cone of the giant geyser in the upper geyser basin of the ,fire-,hole1 ,yellowstone ,national ,park4 ,this cone is about ten feet in height1 and twenty-four feet in diameter4 ,as shown in the figure it is broken on one of its sides4 ,it throws out1 at long intervals1 a column of water the height of which varies from ninety to #bjj feet4 ,fig4 #ch represents the crater of a cone known as the ,bee ,hive in eruption4 ,besides the above named geyser regions there is another region on the shores of ,celebes1 and a small region on ,san ,miguel1 in the ,azores ,islands1 in the ,atlantic ,ocean4 ,besides hot springs and mud volcanoes there are two other phenomena connected with volcanic action that we will now briefly describe4 ,when eruptions take place and the lava begins to flow down the side of a mountain1 the different vapors and gases with which the lava is charged begin to escape or pass out from the boiling or fused mass4 ,when these substances are of such a character that they produce fumes1 or the vapors of various chemical substances1 that become solid on cooling1 they form what are called fumaroles1 a word derived from a ,latin word meaning to smoke4 ,for the greater part1 fumaroles are found on the edge of craters1 but sometimes are found in cavernous places either in the crater or in the lava streams4 ,there is1 still1 another class of openings through which only sulphurous vapors escape4 ,these are called solfataras1 a word derived from the ,italian word solfo1 or sulphur4 ,solfataras are generally found in regions distant from volcanic action4 ,in the materials that escape from recently ejected lava1 or molten lava1 the temperature is high enough to volatilize many of the solid ingredients4 ,but where the temperature is low1 only sulphur vapors are driven off4 ,it is for this reason that fumaroles are only found around the craters of active volcanoes1 or on the lines of cracks or crevices of the lava stream where the temperature is very high4 ,illustration3 ,,fig4 #ch4 ,,bee ,,hive ,,geyser ,,of ,,iceland ,from ,dana's ,manual of ,geology ,besides water vapor and sulphurous vapors there are other substances that escape from the earth in volcanic districts4 ,sulphurous acid1 together with hydrogen and nitrogen escape from nearly all lava4 ,at ,vesuvius chlorine gas is given off4 ,this1 however1 as soon as it passes into the atmosphere becomes changed into hydrochloric acid4 ,sulphurous acid is frequently changed into sulphuric acid1 which1 combining with various substances1 forms such materials as gypsum1 or sulphate of lime1 the chemical name for plaster of ,paris2 sulphate of soda or ,glauber's salt2 sodium chloride or common table salt2 and sal ammoniac4 ,you will remember in reading the description of ,vulcano1 in the ,grecian ,archipelago1 that some of these products were collected at the chemical works that had been established on the volcano4 ,when a volcanic mountain is for the time being passing from an active to an extinct condition1 it is sometimes said to be in the fumarole stage1 since the presence of the fumaroles are the only indication of its activity4 ,the volcanic heat is still great4 ,when it reaches a still greater decline1 the fumaroles disappear1 and only solfataras are left4 ,the amount of heat is now only sufficient to produce sulphur vapors and the vapor of water4 ,this is called the solfatara stage4 ,of course1 as we have already pointed out1 fumaroles and solfataras may occur in the neighborhood of a volcano at different distances from its crater4 ,,chapter ,,xxii ,,the ,,volcanoes ,,of ,,the ,,moon ,there can be no doubt that the moon was once the seat of very great volcanic activity4 ,it was formerly believed that the very many volcanic craters which can be seen on its surface when it is examined by a comparatively small telescope1 were all extinct4 ,while this is nearly true1 yet recent investigations have shown that in all probability a feeble volcanic activity still exists in a few of these craters4 ,the distinctness with which the surface of the moon is seen does not depend so much on the size of the telescope employed1 as it does on the steadiness of the atmosphere when the telescope is being used4 ,when one wishes to examine a very distant body like a star1 it is necessary to use a powerful telescope1 but in the case of a comparatively near body1 like one of the planets or the moon1 a big telescope is not necessary4 ,it is1 however1 necessary to make the observations at some time of the year1 or in some part of the world1 when the air is apt to be free from winds4 ,a person on the earth's surface looking at the heavenly bodies through a telescope is practically in the position in which he would be were he at the bottom of the water in a large lake looking up through the water at some body in the heavens4 ,he would have no difficulty in seeing such a body distinctly as long as the upper surface of the water remained quiet1 and unruffled by waves4 ,as soon1 however1 as waves were set up1 the images seen in the telescope are so distorted as to become practically worthless4 ,it is for this reason that it is customary to build great astronomical observatories in parts of the world where there are apt to be many days in the year when the air is almost entirely free from wind4 ,since the atmosphere is apt to be disturbed by winds in both the temperate and the polar latitudes1 these parts of the world are not very satisfactory as sites for astronomical observatories4 ,the conditions are more favorable near the equator1 since1 although at certain seasons of the year there are very severe storms in these regions1 yet there are quite long periods when the air is almost entirely free from winds4 ,it is for this reason that ,harvard ,university has erected an astronomical observatory at ,arequipa1 ,peru1 at an elevation of #h1jjj feet above the level of the ,pacific ,ocean4 ,here1 with a comparatively small object glass1 of about twelve inches aperture1 magnificent photographs have been obtained not only of the moon but also of the planet ,mars4 ,according to ,professor ,pickering1 from whose magnificent work1 entitled1 ,the ,moon1 much of the information in this chapter has been obtained1 the moon1 which is generally spoken of as a satellite of the earth1 ought rather to be called the earth's twin planet4 ,although the moon appears to revolve in a small elliptical orbit around the earth it should properly be said to revolve around the sun2 for1 together with the earth1 it revolves around the sun once every year4 ,as seen from any of the planets that lie near the earth the earth and moon would appear as a very beautiful double star4 ,in order the more readily to understand what will be said shortly concerning the origin of the moon1 it may be mentioned that the moon's diameter is #b1afc miles1 or a little more than one-fourth the diameter of our earth4 ,you will1 most probably1 be surprised to learn that the origin of the moon is believed to be very different from the origin of the moons or satellites of ,jupiter1 ,saturn1 and the other planets4 ,as we have already seen1 according to the nebular hypothesis1 all the planets except the earth probably had their moons formed from the rings that were left surrounding them when they shrunk on cooling to their present dimensions4 ,such a ring is still to be seen surrounding ,saturn4 ,now it is believed that our moon was formed in a different manner4 ,it was not thrown off from the earth while the latter was in a highly fluid or gaseous condition1 but after the earth had shrunken to nearly its present size and1 most probably1 after a solid crust had been formed on its surface4 ,in order that our earth should be able to violently throw off a large portion of its mass1 it is only necessary that at the time this separation occurred1 its motion of rotation on its axis was sufficiently great to enable it to make one complete revolution in rather less than three hours instead of in the twenty-four hours it now requires4 ,at this velocity of rotation1 objects would fly off the earth in the neighborhood of the equator1 under the influence of the high centrifugal force4 ,let us1 then1 endeavor to see if it was at all probable that the earth ever did turn so rapidly on its axis4 ,you all probably know that it is principally the attraction of the moon that produces the earth's tides4 ,of course1 the sun also produces tides on the earth1 but it is so far off from the earth that not withstanding its greater mass the tides it forms are much smaller than those produced by the moon4 ,you also know that the moon produces at the same time two tides in every twenty-four hours1 on directly opposite sides of the earth2 one on the side immediately under the moon1 and the other on the side furthest from the moon4 ,as the earth rotates between these two tides1 they act as a break which serves to impede its motion4 ,every high tide1 therefore1 tends to make the earth rotate more slowly1 and thus to slowly increase the length of the day4 ,for this reason to-day is a trifle longer than yesterday1 and still longer than a day a hundred years ago4 ,you must not suppose for a moment that this increase in the length of the day is large4 ,on the contrary1 it is so small that since the year ,a4 ,d4 #a1 up to the present time1 the day is only a very small fraction of a second longer4 ,but it was very different in the earth's geological past1 when the inside of the earth was in a molten condition2 for then great tides were set up in the melted interior of the earth that not only greatly changed the shape of the earth1 but decreased the rate of rotation much more rapidly than it does when the earth's tides are limited as they are now to the waters on the earth's surfaces4 ,there was1 however1 at the same time1 something going on that tended greatly to make the earth turn more rapidly on its axis4 ,while the originally melted earth was cooling and shrinking1 the rate of its rotation was necessarily increasing4 ,as you know1 the time of vibration of a pendulum1 that is1 the time it requires to make one complete to-and-fro motion1 is shorter the shorter the length of the pendulum4 ,a pendulum two feet long moves to and fro more slowly than a pendulum one foot in length4 ,in the same way a rotating sphere will make one complete rotation in a shorter time when its radius1 which corresponds to the length of a pendulum1 is shorter4 ,therefore1 as the earth shrunk1 it rotated more and more rapidly1 and at last reached a rapidity of motion at which an immense quantity of matter flew off its surface nearest the equator and went out into space1 never again to return4 ,it was this mass that constituted the earth's moon4 ,necessarily such a tremendous catastrophe was attended by an earthquake as well as by the most fearful volcanic phenomena that the earth has ever witnessed4 ,the terrible catastrophe produced by the explosive eruption of ,krakatoa was but as a small drop of rain falling on the earth1 when compared with the catastrophe produced when the five thousand million cubic miles of material left the earth's surface1 never again to return to it4 ,it is not known whether this matter was torn off the earth at a single time or during successive times1 but quoting the beautiful language of ,professor ,pickering3 ,we may try in vain to imagine the awful uproar and fearful volcanic phenomena exhibited when a planet was cleft in twain1 and a new planet was born into the solar system4 ,this terrible catastrophe took place at a time not when the earth was a gaseous mass1 but when it had condensed into a comparatively small mass not much larger than it is at its present time1 and possibly even after it had hardened sufficiently to form a solid crust on its outside4 ,if you look at a map of the earth on a ,mercator's projection1 such1 for example1 as that employed in illustrating the distribution of the world's volcanoes in ,fig4 #bd1 you can see1 even without any very close examination1 that the great water area of the ,atlantic ,ocean has its eastern and western shores almost parallel to each other1 so that if you conceive the ,eastern and ,western ,continents as being pushed together1 they would1 except at the south1 almost completely fit together1 and the same thing is true1 if ,greenland is pushed towards the northeastern coast of ,north ,america4 ,of course1 some portions of the coast would not fit exactly1 but then these portions might either have been worn away1 or1 as is more probable1 have been changed in shape by the deposit of immense beds of sedimentary rocks spread over the borders of the ,atlantic by the great rivers that empty into it4 ,this is so remarkable a fact that it will be well worth your while to turn to the map mentioned and convince yourself of the proof of what ,i have just said4 ,as you will see1 ,europe and ,africa would almost exactly fit against ,south ,america and ,north ,america1 while ,greenland would even more closely fit against the northeastern coast of ,north ,america4 ,now1 while we do not say that it was so1 it has been suggested as just possible that the great depression of the ,pacific ,ocean represents the spot that was once filled by the moon4 ,that the ,eastern and ,western ,continents1 then torn asunder by the great force of the convulsion1 were left floating on the surface of a sea of molten matter1 a greatly widened crack marking positions they assumed at the end of this cataclysm4 ,of course1 you must understand that all this is a mere supposition1 and that we do not know whether the earth was actually cooled on the outside when this occurred1 since it might have still been in a liquid condition throughout4 ,it would seem1 however1 to have occurred rather recently1 since it could not have occurred until the earth shrunk so much that it became so small in radius as to acquire a very rapid rate of motion on its axis4 ,it is an interesting fact that we are1 perhaps1 better acquainted with that side of the moon which is turned towards us than we are with the surface of the earth on which we live4 ,of course1 ,i do not mean in the small details of the moon's surface1 but with such portions as can be seen through a good telescope when the air is quiet4 ,while there are no parts of the moon's surface that have not been carefully examined in detail probably thousands of times by acute astronomers1 there are still comparatively large areas of the earth that have never been once trodden by civilized man4 ,when ,i speak of all parts of the moon's surface1 ,i only mean those parts that are turned towards us4 ,you may possibly be ignorant of the fact that the moon always turns exactly the same face towards the earth4 ,not only has no man ever seen the opposite side of the moon1 but he never can hope to see it while he remains on the earth4 ,this is because the moon turns or rotates on its axis in exactly the same time that it revolves in its orbit4 ,when ,i say that the time of rotation is the same as the time of revolution of the moon1 ,i do not mean that it is almost the same1 but that it is exactly the same4 ,if it differed even but a small fraction of a second1 a time would come when we would be able to see the other side of the moon4 ,now1 since astronomers have made careful pictures of the moon1 many1 many years ago1 we can see by comparing them with photographs taken at the present time there has been no change whatever in that face of the moon which is turned towards us1 and this1 of course1 proves beyond question1 that the time of the moon's rotation during this great period has remained exactly the same as the time of its revolution4 ,it may possibly seem to you that it cannot be a matter of great importance in a book like this on the ,wonders of ,volcanoes and ,earthquakes1 whether or not the moon always turns its face towards the earth2 on the contrary1 it is a matter of the greatest importance since by it we can prove positively that the moon was at one time at least in a partly fluid condition4 ,it was the presence of this partly fluid interior that resulted in the time of the moon's rotation agreeing exactly with the time of its revolution4 ,the tides of the earth set up in the moon's molten interior1 tides1 that instead of reaching twice every day the height of a few feet only1 were set up in the molten mass in the moon's interior1 probably reaching miles in height1 rapidly decreased the time of the moon's rotation until the moon rotated once only during every complete revolution4 ,even now that the moon is probably solid throughout1 the time of its rotation and revolution exactly agree because1 while in a molten condition1 the action of the earth changed its shape from that of an exact sphere to a spheroid1 with its longest axis in the direction of the earth4 ,even1 therefore1 if the moon at any time began to rotate faster than the earth1 the earth acting on its projecting surface retarded it until the time of its rotation agreed exactly with the time of its revolution4 ,it was at one time believed that the moon had no atmosphere4 ,it is now known1 however1 that it has an atmosphere4 ,it is true this is a rare atmosphere1 probably not greater in density than the one-ten thousandth of the earth's atmosphere4 ,this important question was settled once for all on ,august #abth1 #ahib1 at the ,harvard ,observatory at ,arequipa1 ,peru1 when a photograph was taken of an object on the moon4 ,it could be readily seen on examining this photograph that the light coming from the moon experienced a bending1 known as refraction1 in passing from the space outside the moon to its atmosphere on to its surface4 ,of course1 when the moon was thrown off from the earth by reason of its great centrifugal force1 it carried along with it a portion of the earth's atmosphere4 ,but since the quantity of matter in the moon is only about one-eightieth of that of the earth1 the force of gravity on the moon is much smaller than that on the earth1 being almost exactly one-sixth that of the earth's gravity4 ,in other words1 if you could succeed in reaching the moon's surface1 you would only weigh one-sixth of what you weigh on the earth1 but then you could carry a weight six times heavier with no greater effort1 and1 as for running1 jumping1 and other athletic exercises1 the surface of the moon would1 indeed1 be a great place on which to break records1 since one could readily jump six times higher1 put the shot six times further1 than on the earth1 or go through most other athletic exercises with a corresponding increase4 ,without going any further into this question it will be sufficient to say that the moon's present atmosphere is believed to consist of carbonic acid gas1 and that while on the general surface of the moon this atmosphere must be very rare1 yet1 at the bottom of the great fissures that cross the moon's surface1 it may possess a fairly great density1 especially if the moon still possesses feeble volcanic activity2 that carbonic acid gas is still being given off from the inside of the moon as we know it is being given off from inside the earth4 ,under the best conditions of atmosphere and telescope1 we can see the moon's surface as it would appear at a distance varying from #hjj miles to #cjj miles from the earth4 ,with a fifteen-inch telescope1 under perfect conditions of vision1 objects can be seen as if they were at a distance of #hjj miles from the earth1 and with the most powerful glasses1 and the best conditions of atmosphere this distance can be reduced to about #cjj miles4 ,this would enable us to clearly see large objects like rivers1 lakes1 seas1 or forests1 if they existed1 but would not be sufficient to enable us to see houses1 buildings1 or roads4 ,when we come to examine the surface of the moon under the most favorable conditions1 we find that it is extremely irregular4 ,there are plenty of high mountains4 ,these mountains are not collected in ranges as they are on the earth's surface1 but are completely separated from each other1 and are scattered in great numbers over the moon's surface4 ,you may form some idea of the number of volcanoes that have been observed on the moon when ,i tell you that as many as #cb1jjj have been seen on that side of the moon that is turned towards the earth4 ,now it is an interesting fact that almost all these mountains possess great craters that are not unlike some of the volcanic craters we see on the earth4 ,the volcanic craters of the moon1 however1 are of very much greater size than those on the earth1 many being from fifty to sixty miles in diameter1 while some of them are more than #ajj miles in diameter4 ,smaller craters1 say from twenty to twenty-five miles in diameter1 can be counted by the hundreds4 ,like most of the moon's craters1 the largest crater more closely resembles one of the pit-craters or calderas on the island of ,hawaii4 ,this volcanic crater consists of a huge circular ring with a small irregular peak that rises inside the ring4 ,this peak1 by the way1 might at first appear to resemble the crater of ,vesuvius1 which after a long period of inactivity of the mountain during the eruption that destroyed ,pompeii and ,herculaneum was thrown up inside of what had been left standing of the old crater of ,somma4 ,but it has no crater at its summit1 and1 therefore1 resembles rather the irregular pile or rock that rises from the surface of a lava lake in the craters of ,mt4 ,loa or ,mt4 ,kilauea in ,hawaii4 ,besides the numerous craters to be seen on the moon's surface there are many lines of deep1 crooked valleys1 known as rills1 that may at one time have been the beds of rivers4 ,besides the rills1 there are many straight clefts about half a mile in width1 that extend down into the surface of the moon for unknown depths4 ,these clefts can be seen passing directly through mountains and valleys4 ,they are believed to be cracks or fissures in the moon's surface4 ,on the moon is a great crater called ,tycho4 ,it is situated near the moon's south pole4 ,the great crater of ,tycho is by far the most prominent object on the moon's surface4 ,it has a system of rays that extend for great distances around its craters4 ,you will also see if you examine the moon's surface by a powerful glass that there are immense plains called oceans or seas4 ,by an appropriate custom the names of the different craters on the moon are the same as the names of the great astronomers and philosophers that have long since passed from their labors1 such as ,tycho1 ,copernicus1 ,kepler1 ,plato1 etc4 ,various explanations have been given as to the origin of the craters on the moon's surface1 but without going into a discussion it may be said that they are now generally regarded as having been formed in the main just as were the craters of the earth's volcanoes4 ,the tremendous size of the moon's craters is of course due to the great decrease in the force of gravity4 ,this would make the craters1 approximately1 six times as great as the craters on the earth4 ,professor ,pickering points out that while the moon's craters resemble more closely those of ,hawaii than those of any other of the earth's volcanoes1 yet there is this difference in them3 that while the earth's crater floors are generally considerably higher than the level of the sea1 the moon's crater floors are generally below the level of the surrounding country4 ,still1 taking them all in all1 the craters of the moon's volcanoes resemble those of the island of ,hawaii1 or again quoting from ,pickering3-- ,there seems1 indeed1 to be no feature found upon the moon which is not presented by these ,hawaiian volcanoes1 there is no feature of the volcanoes that does not also have its counterpart in the moon4 ,,chapter ,,xxiii ,,earthquakes ,an earthquake is a shaking of the earth4 ,it may vary in intensity from a shaking so feeble that it requires the use of a delicate instrument to detect it1 to a shaking violent enough to overthrow heavy buildings1 and even to make great rents or fissures in the crust4 ,an earthquake then is an earth-shake4 ,it may be caused by anything capable of shaking the earth2 for example1 as the falling of a heavy weight on its surface4 ,now1 a shaking so caused is only felt in the immediate neighborhood of the place the weight strikes the earth4 ,on the contrary1 in an earthquake1 the shaking spreads in all directions through the earth's crust1 until1 in the case of very violent earthquakes1 it reaches portions that may be situated many thousands of miles away from where the shock started4 ,this spreading of the earthquake waves through the solid earth is not unlike the spreading of the circular waves that are set up in a still water surface when a stone is tossed in4 ,any shaking of the earth's crust produces what may be called an earth-shake or earthquake4 ,the mere falling of a raindrop on the earth produces a slight shaking4 ,the falling of a heavy stone produces a stronger shaking1 and sets up a series of minute waves1 generally called vibrations1 that spread around the place in all directions from where the stone struck4 ,these movements1 however1 while they spread in all directions1 just as they do in a surface of a lake1 when a stone is thrown into it1 are of course much more quickly stopped by the solid earth than similar movements are by the more readily movable water4 ,but1 while any shaking of the earth's crust constitutes an earthquake1 yet1 strictly speaking1 an earthquake is produced only by some force that acts suddenly on the earth1 at a point below its surface1 and1 therefore1 out of sight4 ,this1 of course1 would rule out all such shakings as are caused by bodies striking the outer surface of the earth4 ,earthquakes may occur in any part of the world1 and at any time of the day or year4 ,they do occur1 however1 most frequently in certain parts of the world1 at certain seasons of the year and at certain hours of the day4 ,earthquakes are far from being unusual occurrences4 ,in some parts of the world1 such as the island of ,java1 they are very common1 and in ,japan1 under certain circumstances1 scarcely a day passes without one or more shocks in some part of that little empire4 ,professor ,mallet1 who has made a very extensive study of earthquakes1 published in #ahej to #aheh1 in the ,philosophical ,transactions1 brief abstracts or descriptions of all the more important earthquakes he could find records of during the past #c1def years4 ,the number of earthquakes thus recorded during this period reached #f1hcj4 ,of this great number nearly one-half occurred during the last fifty years4 ,it should not be inferred from the above figures that the number of earthquakes has really increased so greatly in the past half-century4 ,the explanation of the apparent increase is that greater care has been taken recently in recording earthquakes1 and that an apparatus called a seismometer1 or earthquake-recorder1 has been invented which automatically produces a record of the smallest shocks2 so that a great many have been recorded that would otherwise have passed undetected4 ,it is the opinion of ,le ,conte that if the records of all the earthquakes of #c1def years had been thus made there would have been found during the entire time of ,mallet's researches to have occurred no less than #bjj1jjj1 while during the last four years of ,mallet's records1 the number would have probably reached two earthquakes per week4 ,since ,mallet's time1 ,prof4 ,alexis ,perry published 7#ahgf7 a much larger list of earthquakes4 ,perry finds that from #ahdc to #ahgb there have been #ag1bdi earthquakes1 or #ege every year4 ,perry's list1 however1 is incomplete1 since it fails to record earthquakes that occurred in mid-ocean1 and in the unexplored and uncivilized parts of the world4 ,so it seems likely that earthquakes are so common that our earth1 at some part or other of its surface1 is continually shaking or quaking4 ,earthquakes are such tremendous phenomena that they were necessarily observed by the ancients4 ,we find more or less complete accounts of them in various writings4 ,lucretius 7,titus ,carus ,lucretius1 a great ,roman poet7 speaks as follows1 in his ,de ,rerum ,natura 7,on the ,nature of ,things74 ,we use ,munro's translation here3 ,now mark and learn what the law of earthquakes is4 ,and first of all take for granted that the earth below us as well as above is filled in all parts with windy caverns1 and bears within its bosom many lakes and many chasms1 cliffs and craggy rocks2 and you must suppose that many rivers hidden beneath the crust of the earth roll on with violent waves and submerged stones2 for the very nature of the case requires it to be throughout like to itself4 ,with such things then attached and placed below1 the earth quakes above from the shock of great falling masses1 when underneath1 time has undermined vast caverns4 ,whole mountains1 indeed1 fall in1 and in an instant from the mighty shock tremblings spread themselves far and wide from that centre4 ,and with good cause1 since buildings beside a road tremble throughout1 when shaken by a wagon of not such very great weight2 and they rock no less1 where any sharp pebble on the road jolts up the iron tires of the wheels on both sides4 ,sometimes1 too1 when an enormous mass of soil through age rolls down from the land into great and extensive pools of water1 the earth rocks and sways with the undulation of the water just as a vessel at times cannot rest1 until the liquid within has ceased to sway about in unsteady undulations4444 ,the same great quaking likewise arises from this cause1 when on a sudden the wind and some enormous force of air gathering either from without or within the earth have flung themselves into the hollow of the earth and there chafe at first with much uproar among the great caverns and are carried on with a whirling motion1 and when their force1 afterwards stirred and lashed into fury1 bursts abroad and at the same moment cleaves the deep earth and opens up a great yawning chasm4 ,this fell out in ,syrian ,sidon and took place at gium in the ,peloponnese1 two towns which an outbreak of wind of this sort and the ensuing earthquake threw down4 ,and many walled places besides fell down by great commotions on land and many towns sank down engulfed in the sea together with their burghers4 ,and if they do not break out1 still the impetuous fury of the air and the fierce violence of the wind spread over the numerous passages of the earth like a shivering-fit and thereby cause a trembling4 ,of course1 no one at the present time believes this ridiculous explanation as to the cause of earthquakes4 ,aristotle1 a ,greek philosopher1 speaks thus concerning earthquakes4 ,we quote the translation employed by ,mallet3 ,three theories on the subject have been handed down to us by three different persons2 namely1 ,anaxagoras of ,klazomene1 before him ,anaximenes the ,milesian1 and later than these ,democritus of ,abdera4 ,anaxagoras says that the ether of nature rises upward1 but that when it falls into hollow places in the lower parts of the earth it moves it 7the earth72 because the parts above are cemented or closed up by rain1 all parts being by nature equally spongy or full of cavities1 both those which are above 7where we live7 and those which are below4 ,of this opinion it may perhaps be unnecessary to say anything1 as being foolish1 for it is absurd to suppose that things would thus exist above and beneath1 and that the parts of bodies which have weight would not on every side be borne to the earth1 and those which are light1 and fiery1 rise2 especially since we see the surface of the earth to be convex and spherical1 the horizon constantly changing as we change our place1 at least as far as we know4 ,and it is also foolish to assert on the one hand that it remains in the air on account of its great size1 and on the other to say that it is shaken1 when struck from beneath upwards4 ,and besides these objections1 it is to be remarked that he has not treated of the attendant circumstances of earthquakes1 for neither every time nor place is subject to these convulsions4 ,but ,democritus says1 that the earth being full of water1 and receiving much also by means of rain1 is moved by this4 ,for when the water increases in bulk1 because the cavities cannot contain it1 in its struggles it causes an earthquake4 ,and when the earth becomes partially dried up1 the water being drawn from the full reservoirs into those which are empty1 in passing from one to the other1 by its movements it causes an earthquake also4 ,anaximenes1 however1 says that the earth1 when parched up and again moistened1 cracks1 and by the masses thus broken off falling on it1 is shaken2 wherefore earthquakes occur in drouths and again in times of rain2 in drouths1 because1 as we have said1 it cracks1 when highly dried1 and then1 when moistened over again1 it cracks and falls to pieces4 ,were this the case1 however1 the earth ought to appear in many places subsiding4 ,why then is it that hitherto many places have been very subject to these convulsions which do not present any such remarkable differences from others8 ,yet such ought to be the case4 ,and1 moreover1 those who think thus must assert that earthquakes constantly become less and less1 and at last cease altogether4 ,for the continual condensation of the earth would cause this4 ,wherefore1 if this be not the fact1 it is plain that this is not the correct explanation4 ,besides the above1 there are numerous references to earthquakes in the works of other writers4 ,thales1 ,seneca1 and ,pliny all speak of these phenomena and appear to describe correctly the movement of the earth in waves both in the solid land1 as well as on the sea4 ,coming down to less ancient writers1 ,mallet refers to a book by ,fromondi1 published in ,antwerp1 in #aebg1 that contains much valuable and interesting information4 ,among other things ,fromondi declares that in the year #cfi1 in the reign of ,valentinian1 there was a great earthquake that shook nearly the entire world and that another earthquake of almost equal severity occurred in #aaaf4 ,he also states that in #afja an earthquake continued for nearly forty days2 that a great earthquake in ,italy1 in #aech1 lasted fifteen days1 and that another1 in ,spain1 lasted for nearly three years4 ,this does not mean that these earthquakes actually continued to shake the earth violently for the times mentioned4 ,these are only the times during which1 at intervals of greater or less length1 successive shocks were felt in these localities4 ,another of the less ancient writers referred to by ,mallet is ,travagini1 who published a book in ,venice in #afhc4 ,this book contains a description of a terrible earthquake occurring in ,italy on the #fth of ,april1 #affg1 which affected large portions of the country adjacent to ,ragusa4 ,without attempting at present to discuss the various theories of earthquakes1 it will suffice to say that earthquakes can be divided1 according to their origin1 into two classes3 volcanic earthquakes1 or earthquakes that are caused by practically the same forces that cause volcanoes1 and tectonic#c earthquakes1 or those produced by the slipping of a large mass of rock lying along the lines of old or new fractures4 ,earthquakes of the first class are found especially in volcanic districts1 while those of the second class are found in all parts of the world1 whether in volcanic districts or elsewhere4 ,according to ,dana1 earthquakes of the second class generally start in the neighborhood of mountains1 where old lines of fractures are especially abundant4 ,as regards the direction of the shaking movements of the earth1 earthquakes can be divided into three different classes3 explosive earthquakes1 or those in which the force acts vertically upwards2 horizontal earthquakes1 or those in which the force moves in a more or less horizontal direction1 or parallel to the general surface of the earth1 and rotary earthquakes1 or those in which the earth rotates or moves in great eddies or whirls4 ,when the earthquake wave is started below the earth's surface1 it spreads through the crust in all directions4 ,the direction these waves will have on emerging1 or coming out of the surface1 will depend on the distance of this point from the place the waves started4 ,when a place is situated directly over where the wave started1 the waves will emerge so as to move vertically upwards1 so that the earth at this point will be shaken by an explosive earthquake4 ,as the point where the waves pass out is situated further and further from the place where the waves start1 the waves will emerge more nearly horizontally1 the greater the distance from the source4 ,in explosive earthquakes1 which1 as just explained1 occur at areas almost immediately above the point where the disturbance starts1 the force is1 generally speaking1 the greatest4 ,in earthquakes of this character the force is sometimes sufficiently great to throw large bodies high up into the air4 ,in the case of the great ,riobamba earthquake of #agig1 the force was not only sufficiently great to fracture the earth in various places1 but also to throw bodies lying on the surface great distances into the air4 ,bodies of men were thrown several hundred feet into the air and were afterwards found on the other side of a broad river or high up on the side of a hill4 ,it is possible that ,humboldt did not inquire with as much care as he should have done into these reports4 ,they were probably greatly exaggerated1 since it is difficult to understand how a force great as this would have failed to detach the soil at these places1 and hurl it after the people4 ,this much1 however1 can be accepted1 that the upward force was very great4 ,in the great ,calabria earthquake of ,march1 #aghc1 ,dolomieu states that the tops of the granite hills of ,calabria were distinctly seen to rise and fall4 ,in some cases houses were suddenly raised a great distance in the air1 and were afterwards brought down again to a position of rest1 at a higher level without any damage occurring to them4 ,in a similar manner during the ,caracas earthquake of ,march1 #ahab1 the ground was seen to rise and fall in a nearly vertical direction4 ,but1 perhaps1 one of the most terrible earthquakes of this character was the earthquake that destroyed the greater part of ,jamaica in ,june1 #agic4 ,during this earthquake the entire surface of the ground at ,port ,royal assumed the appearance of a rolling sea4 ,houses were shifted from their old sites4 ,many of the inhabitants who had succeeded in escaping from the city to the neighboring country were thrown great distances into the air4 ,some of these1 by good fortune1 fell into the harbor1 from which1 in some cases1 they escaped with their lives4 ,here again the projectile force was probably greatly exaggerated4 ,vertical movements characterized the great earthquake of ,lisbon1 on ,november #ast1 #agee1 the city appearing to have been not far from the point of origin4 ,the commonest type of earthquakes is the horizontal1 where the waves emerge at the surface in a direction either horizontal or parallel to the general surface1 or at least inclined to it at a very small angle4 ,where the materials of the earth's crust1 through which the waves spread1 are of the same kind and of the same density in all directions1 the area shaken is approximately circular1 but where the materials of the crust are more or less dense in some directions than in others1 the area of disturbance is of course oblong or elliptical4 ,in some cases earthquakes of the horizontal type are limited almost entirely to a single direction4 ,this is especially the case with earthquakes that occur in mountainous districts4 ,these earthquakes are known as linear earthquakes1 since they spread almost in a single line4 ,when earthquake waves pass from one medium to another1 that is1 from one kind of rock to another1 the greater portion of the waves is refracted or bent out of their straight direction as they pass into the new medium2 a part of the waves1 however1 are reflected4 ,it is these reflected waves that probably cause rotary earthquakes4 ,the speed with which the surface waves move outwards in all directions1 varies not only with the force of the wave1 but also with the kind of material through which they pass4 ,this velocity may be in the neighborhood of twenty miles per second1 while in others the velocity is as great as #adj miles per second4 ,naturally1 one would suppose that the most severe earthquakes are those in which the waves move the most rapidly4 ,on the contrary1 however1 the comparatively feeble shocks are sent through the earth with greater velocity4 ,in rotary earthquakes1 as the name indicates1 the ground is whirled or twisted in the manner of a violent eddy1 and is often left in this twisted condition4 ,in the great ,calabria earthquake1 huge blocks of stone forming obelisks were twisted on one another in a manner represented in ,fig4 #ci4 ,in this case the pedestals remained unaffected1 but the separate blocks of stone were partially turned around1 as shown4 ,during this earthquake the earth was so twisted that trees1 which had been planted in straight lines before the earthquake1 were left standing in zigzags4 ,during the great ,charleston earthquake1 ,south ,carolina1 the chimney-tops of the houses were separated at places where they joined the roof and were twisted around these places without being overthrown4 ,in some of the houses wardrobes or bureaus were turned at right angles to their former positions1 and in some cases were even found with their faces turned towards the wall4 ,illustration3 ,,fig4 #ci4 ,,heavy ,,stone ,,obelisks ,,twisted ,,by ,,calabrian ,,earthquake ,,of #aghc ,mallet suggests that in some cases the rotary motion is more apparent than real1 being due only to a to-and-fro motion without any twisting1 the apparent turning being due to the greater freedom of motion of the object in one direction than in another4 ,a twisting motion1 however1 has actually taken place in some earthquakes4 ,while separate shocks1 in a given locality1 may follow one another at intervals for fairly long times1 yet the principal shock or shake that produces the greatest damage is generally of exceedingly short duration4 ,in the ,caracas earthquake the greatest destruction was accomplished in about one minute4 ,there were three distinct shocks1 each of which lasted but three or four seconds4 ,the great ,calabria earthquake1 of #aghc1 lasted but two minutes4 ,the earthquake of ,lisbon1 in #agee1 lasted five minutes1 but the first1 and worst1 shock1 was only from five to six seconds4 ,,chapter ,,xxiv ,,some ,,of ,,the ,,phenomena ,,of ,,earthquakes ,the nature of an earthquake and the movements of its waves from their starting place having now been briefly described1 it remains to explain some of the strange phenomena that precede1 accompany1 or follow one4 ,next to the violent shaking of the earth's crust1 perhaps the most wonderful and impressive thing is the great variety of sounds and noises4 ,these occur not only while the earth-waves are passing through the crust at any place1 but also long before the principal shocks reach the place1 as well as long after they have passed4 ,earthquake sounds vary almost infinitely1 both in intensity and character4 ,some are like the gentle sighings of the wind1 or resemble faint mysterious whisperings2 some are not unlike the confused murmurings of a crowded room2 some resemble the sounds of a busy street4 ,some sounds are full and strong1 like the deep bass notes of a large organ4 ,others resemble the din of a great battle with the reports of the large guns4 ,still others reach the intensity of continuous peals of thunder4 ,but we can better understand the nature of earthquake sounds from an actual description of them in a number of great earthquakes1 and by inquiring at the same time into any of the peculiar facts connected4 ,humboldt in his great work1 ,cosmos1 thus describes the varied voice of the earthquake3 ,it is either rolling or rustling1 or clanking1 like chains being moved1 or like near thunder1 or clear and ringing1 as if obsidian or some other vitrified masses were struck in subterranean cavities4 ,that the sounds produced during earthquakes are carried through the ground faster than through the air appears clear from the fact that such sounds are sometimes heard in deep mines when they are not at all heard on the earth's surface4 ,in describing the earthquake that occurred in ,kamtschatka1 in #agei1 ,krashenikoff of ,st4 ,petersburg states that noises were heard like the rushing of a strong underground wind1 accompanied by a hissing sound1 which resembled the sizzlings heard when red hot coals are thrown in water4 ,in an earthquake that occurred in ,lincolnshire1 ,england1 ,february #fth1 #ahag1 a noise was heard closely resembling the sounds of wagons running away on a road4 ,so complete and convincing was the resemblance that several wagoners on one of the roads drew their teams to one side so as to permit the runaway to pass safely4 ,another kind of noise heard during earthquakes is a loud hollow bellowing4 ,sometimes1 however1 the sounds are more musical in their nature1 being not unlike those produced by a very large organ pipe4 ,at other times they resemble the noises produced when steam is blown into cold water4 ,the following account of earthquake sounds is given by ,daubeny1 in his book on volcanoes4 ,it appears that during ,march1 #ahbb1 the people living on the island of ,melida1 opposite ,ragusa1 in ,dalmatia1 were greatly alarmed by sounds that at first they believed due to cannonading either at sea or on the neighboring coast4 ,they afterwards found that these sounds were due to something that was taking place under the ground4 ,the noises continued at intervals until ,august #bc;d1 #ahbc1 when a great earthquake occurred1 during which one of the highest mountains on the island was cleft or split in one place4 ,the underground noises continued from time to time and so frightened the people that they were about to leave the island permanently and emigrate to the mainland of ,dalmatia4 ,they were dissuaded from doing so by the government1 and while the noises continued at intervals it so happened that no damage came to them4 ,it is said1 however1 that twenty years after an active volcano broke out on the island4 ,there are various causes that produce earthquake sounds4 ,a very slight rubbing or grinding together of rock surfaces may produce fairly loud noises1 the volume of the sound being increased by transmission through the rock masses that lie in the path of the waves4 ,an example of such an increase in the loudness of sounds is seen in the case of several of the large blocks of stone used for some of the piers of ,kingston ,harbor1 in ,ireland4 ,when these rocks are moved together by blows of the waves they produce loud and appalling sounds1 as if the whole island were being washed away4 ,the same rocks1 however1 when left high and dry on the falling of the tide1 can be caused to rub together1 when moved by the hand4 ,under these circumstances1 they produce but feeble sounds that can only be heard in their immediate neighborhood4 ,no doubt1 some find it difficult to understand how it is possible for comparatively feeble sound-waves to be strengthened by their passage through large masses of solids4 ,this is important and should be made clear4 ,as everyone well knows1 the ticking of a watch can only be heard at a short distance when the watch is held in the hand1 because the sound-waves cannot readily pass through the body of the person holding the watch to the earth1 the materials of the body not being sufficiently elastic4 ,if1 however1 the watch be placed on the bare surface of a large wooden table from which the tablecloth has been removed1 so that the watch can come directly in contact with the wood1 and nothing else is placed on the table but the watch1 the sound-waves are transmitted to the mass of the table and its entire surface sends them out into the air4 ,the ticking of the watch can then be heard distinctly in almost any part of a large room4 ,mallet states that in nearly all great earthquakes sounds are heard before the principal shock1 and in his description of the ,calabrian earthquake ,hamilton says3 ,all agreed that every shock seemed to come with a rumbling noise from the westward1 beginning with the horizontal and ending with the vorticose 7rotary7 motion4 ,according to ,dolomieu1 during the ,lisbon earthquake1 the shocks were preceded by a loud subterranean noise like thunder1 which was renewed for every shock4444 ,this great shock1 he says1 referring to one of the great upward shocks1 occurred without the prelude of any slight shocks1 without any notice whatever as suddenly as the blowing up of a mine4444 ,some1 however1 pretend that a muffled interior noise was heard almost at the same moment4 ,the noises do not generally continue long after the earthquake shocks4 ,in some cases1 however1 a very loud noise is heard at intervals for a considerable length of time after the principal shock4 ,this was the case at ,quito and ,ibarra1 in which a great noise was heard for from eighteen to twenty minutes after the principal shock4 ,in a similar manner during the earthquake of ,october1 #agdf1 at ,lima1 and ,callao1 ,south ,america1 peals of underground thunder were heard at ,truxillo for fifteen minutes after the principal shock4 ,in such cases it seems probable that the noises were not caused by the same impulses that caused the original shock1 but by the forces that caused the subsequent shock4 ,humboldt relates that in #aghd there were noises heard at ,guanajuato1 from the #ith to the #abth of ,february4 ,they were not1 however1 followed by an earthquake4 ,humboldt also states that in an earthquake which occurred on the #cjth of ,april1 #ahab1 on the banks of the ,orinoco ,river1 in ,south ,america1 a loud thundering noise was heard1 without1 however1 any shock1 but at this time a volcano on the island of ,st4 ,vincent1 in the ,lesser ,antilles1 although some #fcb miles to the northeast1 was pouring out streams of lava4 ,again in the great eruption of ,cotopaxi1 in #agcd1 underground noises were heard as if cannon were being fired4 ,these sounds were distinctly heard at as great a distance as ,honda on the banks of the ,magdalena ,river4 ,now1 bearing in mind that the crater of ,cotopaxi is situated on the high plateau of ,quito1 in a region full of valleys and fissures1 it would seem that for the sounds to have been sent through the #dcf miles between the mountains and the valley of the ,magdalena ,river1 the waves must1 for the greater part1 have been transmitted through the solid earth at some considerable distance below the surface4 ,mallet states that the underground noises which continued for more than a month from the midnight of ,january #ith1 #aghd1 at ,guanajuato1 were not followed by any earthquake shocks1 that it was if as thunder clouds occupied the space below the surface at that part of the earth and from these clouds there came the slow rolling sounds like short1 quick1 snaps of thunder4 ,major ,dutton in his book entitled ,earthquakes in the ,light of the ,new ,seismology gives the following as the principal signs that herald the coming earthquake in the open country4 ,the first sensation is the sound4 ,it is wholly unlike anything we have ever heard before1 unless we have already had a similar experience4 ,it is a strange murmur4 ,some liken it to the sighing of pine-trees in the wind1 or to falling rain2 others to the distant roar of the surf2 others to the far-off rumble of the railway train2 others to distant thunder4 ,it grows louder4 ,the earth begins to quiver1 then to shake rudely4 ,soon the ground begins to heave4 ,then it is actually seen to be traversed by visible waves somewhat likes waves at sea1 but of less height and moving much more swiftly4 ,the sound becomes a roar4 ,it is difficult to stand1 and at length it becomes impossible to do so4 ,the victim flings himself to the ground to avoid being dashed to it1 or he clings to a convenient sapling1 or fence-post1 to avoid being overthrown4 ,the trees are seen to sway sometimes through large arcs1 and are said1 doubtless with exaggeration1 to touch the ground with their branches1 first on one side1 then on the other4 ,as the waves rush past1 the ground on the crests opens in cracks which close again in the troughs4 ,as they close1 the squeezed-out air blows forth sand and gravel1 and sometimes sand and water are spurted high in air4 ,the roar becomes appalling4 ,through its din are heard loud1 deep1 solemn booms that seem like the voice of the ,eternal ,one1 speaking out of the depths of the universe4 ,suddenly this storm subsides1 the earth comes speedily to rest and all is over4 ,there are many other curious phenomena besides earthquake sounds or noises4 ,among some of the more interesting are the fire and smoke that are seen to come out of fissures that have been rent in the ground4 ,it is possible that in many cases these flashes of fire are in reality produced by electric discharges that momentarily light the clouds of dust thrown up out of the fissure4 ,but sometimes true flames are seen escaping from the fissures4 ,this was the case during the earthquake of ,lisbon1 in #agee1 when fire burst through fissures at several places1 burning with a lambent flame for some hours4 ,the clouds of dust that follow the rending of mountain masses by earthquakes are probably to be traced to the fracture of the rock masses1 the dust so formed being violently thrown forth by the air squeezed out of the fissures1 when they are suddenly closed4 ,the violent compression of this air may raise this dust to incandescence4 ,mallet asserts that in many cases the clouds of smoke observed do not consist of true smoke like that produced when wood or vegetable matters are incompletely burned1 but is only ordinary air mixed with sulphurous acid gas1 and various other gases4 ,but not only fire and smoke are seen at times coming out of fissures in the earth4 ,a thing still more frequently thrown out is water1 which often spouts forth along with great quantities of mud1 sand1 and the finely ground fragments of earthy materials generally4 ,among many other instances where the emission of water from the crevices was particularly noticeable1 may be mentioned the earthquakes at ,jamaica in #afhg and #afib4 ,here the water1 in some places1 was thrown out of the ground to considerable heights in the air4 ,mallet calls attention to the fact that the waters of springs collect in reservoirs consisting either of fissures or crevices of the rocks1 of small width but great depth1 which are vertical or inclined to the horizon1 or in reservoirs that are formed of extended beds of sand or gravel4 ,now1 when the earthquake waves moving horizontally over the surface produce movements that squeeze these fissures together1 the water in the fissures is spurted out in high jets1 and carries with it the finely divided rock or sand formed by the rubbing together of the rock surfaces4 ,in the case of the reservoirs consisting of beds of sand or gravel1 lying between impervious layers1 if1 during an earthquake motion1 the land areas are suddenly lowered1 the water rushing into the cavity thus left will afterwards be shot out with considerable force1 when the land is suddenly raised again4 ,where there are no direct openings in the ground the water will burst through the crust in the shape of great vertical jets1 thus forming a circular hole1 broken or fractured at its edges4 ,water jets of this character were especially numerous during the earthquake of ,calabria in #aghc4 ,in a swampy plain1 known as ,rosarno1 many of these circular wells or openings about the size of an ordinary carriage wheel1 though in some cases much larger1 were to be seen crowded together4 ,the appearance of the openings are represented in ,fig4 #dj4 ,some of these were filled with water1 but the greater number were dry and filled with loose sand4 ,these latter1 when examined by digging1 were shown to be funnel-shaped1 as seen in ,fig4 #da4 ,as seen1 the margins of the wells exhibit a series of cracks or crevices extending radially outward from the centre4 ,their origin is evident4 ,as the water was violently expelled by the squeezing motion of the upper and lower impervious strata1 it shot upwards1 thus producing the funnel-shaped tube4 ,at the same time the force of the eruption was sufficiently great to produce the radial fissures or fractures at the sides4 ,illustration3 ,,fig4 #dj4 ,,circular ,,hollow ,,formed ,,by ,,calabrian ,,earthquake ,illustration3 ,,fig4 #da4 ,,section ,,of ,,circular ,,hollow ,,formed ,,by ,,calabrian ,,earthquake ,but greater fissures than these have been formed by earthquakes1 especially those of the class created by a slipping of the earth's strata4 ,in the case of an earthquake on the ,south ,island of ,new ,zealand1 in #ahdh1 a fissure having an average width of eighteen inches could be clearly seen extending in a direction parallel to the mountain chain for a distance of sixty miles1 and during a later earthquake in the same region1 in #ahee1 a fracture was formed that could be clearly traced for a distance of nearly ninety miles4 ,in some cases these fissures or fractured parts of the crust are left with one of their sides at a higher level than the opposite side4 ,this was the case of the great ,japanese earthquake of ,october #bhth1 #ahia4 ,there are three kinds of waves produced by earthquakes2 namely1 the earthquake waves proper through the earth2 the sound waves in the air1 and great forced waves in the sea4 ,the sound waves of course reach the air from the point of origin below the earth's surface through the solid materials of the crust1 and take on the curious varieties already described in connection with the sounds accompanying earthquakes4 ,we have already briefly described the manner in which the earthquake waves travel through the materials of the earth's crust4 ,there remain to be discussed the great waves that are rolled up in the ocean during an earthquake shock4 ,these waves are1 perhaps1 among the most destructive phenomena of great earthquakes4 ,the following are only some of the more remarkable of such waves1 and have been taken from ,mallet's collection of earthquake data4 ,during some of the great earthquakes on the coasts of ,chile and ,peru1 huge waves from the ocean did great damage when they reached the land4 ,in the earthquake of #aeij1 ocean waves rushed for several leagues inland over the coast of ,chile1 carrying with them ships that were left high and dry as the wave receded4 ,in the earthquake of #afhg1 ,callao was inundated by a great wave from the ,pacific ,ocean1 and ships were carried a full league into the country4 ,during the earthquake of #agdf1 ,callao was again swept away by a huge ocean wave4 ,at later times earthquake waves have caused great damage to several other parts of the coast of ,south ,america4 ,ocean waves of this character are formed by successive upward and downward movements at the bottom of the ocean1 following each other at very brief intervals4 ,le ,conte points out that the sudden upheaval of the bed of the ocean forms a huge mound in the surface of the water which results in a large wave that spreads rapidly in all directions4 ,waves produced in this manner sometimes reach a height of fifty to sixty feet4 ,they are not readily observed in the deep ocean1 but as soon as they reach the shallow waters near the shore they rush forward1 forming waves from fifty to sixty feet in height and1 rushing over the land1 sweep everything before them4 ,during the great ,lisbon earthquake of #agee a huge wave started at a point fifty miles off the coast of ,portugal4 ,half an hour after the earthquake was over several waves1 the largest of which was sixty feet in height1 rushed over a part of the city and greatly increased the ruin already wrought by the earthquake4 ,according to ,le ,conte the great waves so formed moved in all directions across the ,atlantic ,ocean4 ,they were thirty feet high when they reached ,cadiz1 eighteen feet in height at ,madeira1 and five feet on the coast of ,ireland4 ,they even crossed the ,atlantic1 being observed on the coasts of the ,west ,indies4 ,a great ocean wave accompanied the ,japanese earthquake in #ahed4 ,as in the case of the ,lisbon earthquake this wave started in the bed of the ocean off the coast of ,japan and only reached the island half an hour afterwards4 ,it was thirty feet in height1 and completely swept away the town of ,simoda4 ,owing to water's greater freedom of motion earthquake waves travel greater distances through the water than they do on land4 ,of course1 great earthquake shocks as a rule cause a very large loss of life4 ,the following figures from ,mallet give some idea of the extent of this loss1 which is generally a matter of a few moments4 ,in the ,lisbon earthquake1 where the worst shock lasted a few seconds1 #fj1jjj people were killed4 ,during other earthquakes the losses have been as follows3 #aj1jjj at ,morocco2 #dj1jjj in ,calabria2 #ej1jjj in ,syria1 and probably #abj1jjj in earthquakes that occurred in ,syria in ,a4 ,d4 #ai and in ,a4 ,d4 #ebf4 ,but even these figures give only a meagre idea of the vast loss of life that has occurred during the past4 ,it is said that during the reign of ,justinian1 earthquakes repeatedly shook the whole ,roman world4 ,the city of ,constantinople was visited by earthquake shocks that continued at intervals for forty days4 ,deep chasms were opened in the earth and huge masses were thrown into the air4 ,enormous sea-waves were formed4 ,at ,antioch1 during the earthquake of ,may #bjth1 ,a4 ,d4 #ebf1 #bej1jjj people are believed to have been killed4 ,on the #cast of ,july1 ,a4 ,d4 #cfe1 in the second year of ,valentinian1 a dreadful earthquake shook the ,roman world1 and a great wave rolled in from the ,mediterranean and swept two miles inland1 carrying ships over the tops of houses4 ,during this earthquake #ej1jjj people lost their lives at ,alexandria4 ,in the earthquake of ,messina in #afib1 #gd1jjj people are said to have been killed2 and1 according to other accounts1 #ajj1jjj4 ,in the year ,a4 ,d4 #fjb1 another earthquake at ,antioch killed #fj1jjj people4 ,during the earthquake of ,quito1 in #agig1 ,humboldt estimates that #dj1jjj natives were either buried in crevices in the earth1 under the ruins of buildings1 or were drowned in lakes and ponds that were temporarily formed4 ,in this connection ,mallet writes as follows3 ,such are the numbers to be met with in narratives1 and if we suppose that there occurs one great earthquake in three years over the whole earth and that this involves the entombment of only #aj1jjj human beings1 and that such has been the economy of our system for the last #d1jjj years1 we shall have a number representing above #ac1jjj1jjj men thus suddenly swallowed up1 with countless bodies of animals of every lower class4 ,sir ,charles ,lyell then with good reason suggests that even in our own time we may yet find the remains of men and of their habitations and implements thus buried deep and embalmed1 as it were1 by earthquakes that occurred in the days of ,moses and the ,ptolemies4 ,necessarily the progress of a great earthquake wave will produce great changes in the earth's surface features2 for example1 landslides1 where immense layers of clay or other material slip or slide to a lower level and are thrown across the course of a river1 causing its waters to be dammed up and then by spreading to form great lakes4 ,sometimes1 after vast bodies of water have been collected in this manner1 disastrous floods result later from a sudden giving way of the barrier1 and the loss thus caused is occasionally far greater than that directly due to the earthquake4 ,permanent changes of level are frequently caused by earthquakes1 as1 for example1 the coast of ,chile during the earthquake of ,november #aith1 #ahbb1 where the coast for many miles was raised from three to four feet above its former plane4 ,in other cases the level of the ground is permanently lowered4 ,this occurred in the ,bengal earthquake in #agfb1 when an area of some sixty square miles suddenly sank1 leaving only the tops of the higher points above water4 ,in some cases of changes in the level of the ground1 large areas being raised in one place and lowered in another1 rivers take new courses1 and their old courses are completely obliterated4 ,,chapter ,,xxv ,,the ,,earthquake ,,of ,,calabria ,,in #aghc ,all students of elementary geography are quick to notice that the extreme southeastern part of ,italy is shaped something like a boot1 which appears to be kicking at the island of ,sicily4 ,this part of the ,mediterranean ,sea has for very many years been the arena or storm centre of more or less intense volcanic activity4 ,to the northwest is the active volcano of ,vesuvius1 as well as the volcanic regions of the ,phlegran ,fields4 ,immediately opposite the point of ,italy1 near the toe of the foot1 is the active volcanic mountain1 ,etna1 while not far from this point is the volcano of ,stromboli4 ,in #aghc this part of the world was visited by a very severe earthquake4 ,since at that time the country was divided into two parts1 known as ,upper ,calabria and ,lower ,calabria1 this earthquake is sometimes spoken of as the earthquake of the ,calabrias1 or more simply as the ,calabrian earthquake4 ,the great mountain range of the ,apennines1 mainly of granite formation1 extends through the central part of ,italy4 ,the lands adjoining the mountains on each side are flat and marshy1 and consequently unhealthy4 ,numerous observers have compiled excellent accounts of the ,calabrian earthquake4 ,these1 having been made by educated persons1 are1 to a large extent free from the inconsistencies and exaggerations apt to characterize descriptions by ignorant persons1 especially when in a condition of excitement or alarm4 ,among reliable writers was ,sir ,william ,hamilton1 who made a personal examination of the region1 soon after the first severe shock1 and collected much valuable information for a paper which was afterwards published in the ,philosophical ,transactions of the ,royal ,society4 ,then1 too1 ,dolomieu1 another scientific man of high ability1 made a careful study of the effects produced by the earthquake4 ,illustration3 ,,fig4 #db4 ,,map ,,of ,,the ,,calabrian ,,earthquake ,,of #aghc ,as can be seen by an examination of the map presented in ,fig4 #db1 the part of ,italy included in the ,calabrias covers an area from north to south almost equal to two degrees of latitude4 ,although the shock extended beyond the limits of ,calabria1 since it reached as far north as ,naples1 as well as over a great part of the ,island of ,sicily1 the territory in which the greatest damage was done did not exceed in area about #ejj square miles4 ,the southern part of ,italy is subject to frequent earthquake shocks4 ,pignatari1 an ,italian physician1 asserts that this region was visited during #aghc by no less than #idi earthquakes1 of which #eja were of the first class1 or degree of intensity1 while in #aghd1 there were #aea earthquakes1 of which ninety-eight were of the first class4 ,it seems that the city of ,oppido1 marked on the above map as midway between the two coasts1 was the point from which the severe earthquake of #aghc started4 ,if one draws a circle1 with a radius of twenty-two miles1 around ,oppido as a centre1 the portions of the ,calabrias that were the most affected will all lie within this circle4 ,the great ,calabrian earthquake was attended by numerous shocks4 ,the first and the most severe shock1 that of ,february #eth1 #aghc1 was only two minutes in destroying most of the houses in all cities1 towns1 and villages on the western side of the ,apennines in this part of ,italy4 ,another severe shock occurred on the #bhth of ,march4 ,this shock was almost as severe as that of ,february #eth4 ,in order to understand many of the effects produced by this earthquake1 inquiry must be made into the geological character of the region4 ,according to ,dolomieu1 the flat country at the slopes of the ,apennines1 known as the ,plain of ,calabria1 is covered with sand and clay mixed with sea shells4 ,these strata have been deposited by the sea from materials that have been obtained by the decomposition of the granite mountain ranges in the ,apennines4 ,the plain is quite level except where it is crossed by deep valleys or ravines1 which have been eroded or cut by the swift mountain torrents4 ,in many cases1 these ravines or valleys have depths as great as #fjj feet4 ,their sides are generally almost perpendicular4 ,consequently1 as ,lyell remarks1 throughout the length of the mountain chain1 the soil1 which adheres but loosely to the granite base of the mountain chain1 could therefore be easily separated from the mountain1 and sliding over the solid steeps of the mountain could readily move1 especially through the ravines or gorges1 to distances in some cases as great as from nine to ten miles4 ,this peculiarity of the country must be thoroughly understood1 since1 otherwise1 it would seem impossible that lands could be carried several miles from their former position1 and often bear along with them almost undisturbed houses1 olive groves1 vineyards1 and cultivated fields4 ,the heaving of the surface of the earth like the waters of the sea1 so common in severe earthquakes1 occurred during the ,calabrian earthquake4 ,in some places this heaving so shook the trees that they bent until their tops touched the ground near their base4 ,parts of the ground were violently thrown upwards into the air as in the explosive type of earthquakes4 ,in many instances the large paving stones were thrown into the air and afterwards found with their lower portions upwards4 ,during the earthquake deep fissures were made in the earth at various localities and there were1 moreover1 marked changes of level4 ,at ,messina in ,sicily the shore was fissured and rent and while before the convulsion the surface had been level1 it was afterwards found to be inclined toward the sea4 ,according to ,dolomieu the following curious incident occurred during the passage of the earthquake waves4 ,a well in the ground of one of the convents of the ,augustines1 lined on the inside with stones1 was so affected by the upward thrust given to the land that its stone lining was left projecting above the level of the earth in the form of a small tower some eight or nine feet in height4 ,frequent instances occurred of deep fissures in the surface of the earth4 ,many of these remained open after the earthquake1 although in other cases they were firmly closed together before the earthquake shocks ceased4 ,illustration3 ,,fig4 #dc4 ,,fissures ,,caused ,,by ,,the ,,calabrian ,,earthquake ,fig4 #dc represents the appearance of certain fissures in a part of ,calabria during this earthquake4 ,these cracks1 it will be noticed1 radiate or pass outward in all directions from a central point1 just like the cracks that are formed in a glass window pane when it is fractured by a stone thrown against it4 ,of course1 the most violent effects were near the origin of the earthquake at ,oppido4 ,here the formation of deep fissures was common4 ,in another part of the country a number of buildings were suddenly swallowed up in a central chasm1 which almost immediately closed1 thus permanently burying all these objects4 ,some idea of the force with which the fissures were afterwards closed can be formed by reflecting on a case where1 in order to recover some of the buried articles1 the ground was dug up at these points1 and it was found that the materials1 human bodies and other objects1 were so jammed together as to make one compact mass4 ,to ,sir ,william ,hamilton a place was shown where the fissures1 though1 when he saw them1 they were not more than a foot in width1 had opened sufficiently wide during the shock to swallow up a hundred goats as well as an ox4 ,an earthquake that caused such marked changes in the appearance of the earth's surface1 naturally made great changes in the direction of the rivers4 ,in one case the end of a small valley was so completely filled with stones and dirt that the water was dammed up1 producing a lake two miles in length and one mile in breadth4 ,in a similar manner no less than #bae lakes were formed in different portions of ,calabria4 ,of course1 in the flat country at the base of the ,apennines1 frequent landslides occurred1 the land sliding into great chasms and continuing to move down them for considerable distances1 so that in many places pieces of land containing olive trees1 vineyards1 and green fields1 were bodily transported for distances of several miles4 ,this1 moreover1 was done so quietly as to leave the houses entirely uninjured1 and the trees and other vegetation continuing to grow up with apparently no marked decrease in vitality4 ,as is usual in such cases1 the sudden and strong blows acting on the waters of the sea1 killed great numbers of fish just as does the explosion of dynamite at a point below the surface of the water2 and in a similar way the fish that usually live at the bottom of the sea in the soft mud1 being disturbed by the earthquake shocks1 came near the surface where they were caught in vast numbers4 ,it is an interesting fact that during this earthquake the volcano of ,stromboli showed a marked decrease in the volume of smoke it gave out4 ,etna1 however1 was observed to emit large quantities of vapor during the convulsion4 ,lyell tells the following story of the ,prince of ,scilla1 who with many of his vassals sought safety in their fishing boats4 ,suddenly1 on the night of ,february #eth1 while some of the people were sleeping in the boat1 and others were resting on a low plain near the sea1 in the neighborhood1 another shock occurred1 a great mass was torn from a neighboring mountain and hurled with a crash on the plain1 and immediately afterwards a wave1 twenty feet or more in height1 rolled over the level plain1 sweeping away the people4 ,it then retreated1 but soon rushed back again1 bringing with it many of the bodies of the people who had perished4 ,at the same time all the boats were either sunk or dashed against the beach1 and the ,prince with #a1dcj of his people was destroyed4 ,the total number of deaths caused by this earthquake in the ,calabrias and ,sicily were estimated by ,hamilton at #dj1jjj4 ,besides these about #bj1jjj more perished in epidemics that followed the earthquake1 or died for lack of proper food4 ,,chapter ,,xxvi ,,the ,,great ,,lisbon ,,earthquake ,,of #agee ,lisbon1 the capital of ,portugal1 on the ,tagus ,river1 is built along both banks for five miles1 and on several small neighboring hills4 ,it is supplied with water by means of an aqueduct1 called the ,alcantara1 which brings the water from springs about nine miles to the northwest4 ,for portions of its length the aqueduct is placed underground1 but where it crosses the deep valley of the ,alcantara it is supported1 for a distance of #b1djj feet1 by a number of marble arches1 which in one place are #bfj feet in height4 ,this fact is put forward not merely for the sake of its artistic interest1 but because1 strange to relate1 this part of the aqueduct remained uninjured during that great earthquake1 the greatest of modern times4 ,on the #ast of ,november1 #agee1 this frightful catastrophe1 according to ,lyell1 from whose excellent account much of the information contained in this chapter has been obtained1 struck the beautiful city almost without any warning4 ,terrible sounds came suddenly from underground2 almost instantly afterward a violent shock threw down the greater portion of the city2 in less than six minutes #fj1jjj people were killed4 ,the place from which this earthquake started must have been situated on the bed of the ocean at some distance from the coast2 for the great wave thus raised in the ,atlantic ,ocean did not reach the mouth of the ,tagus ,river until about half an hour after the most severe shocks were over4 ,the arrival of this wave at the mouth of the ,tagus was announced by the sea retiring to such an extent as to leave the bar dry4 ,then a huge wave1 sixty feet in height1 rolled in from the ocean and completed the work of destruction that had been commenced by the earthquake4 ,so great was the shock that the mountains in the neighborhood were violently shaken and some of them split or fractured in a most wonderful manner4 ,particularly large was the loss of life in the churches whither hundreds hastened for refuge when the shakings of the earth began1 for most of these buildings fell and buried the worshippers4 ,another immense loss of life was caused by the destruction of a large marble quay or wharf that was suddenly swallowed up by the sea4 ,while the buildings in the city were being overthrown by the violent shakings of the earth1 a multitude sought the quay as a flat place where they could not be injured by the falling buildings4 ,suddenly1 however1 this structure sank into the water and not only were all the people drowned1 but none of the bodies was ever afterwards found4 ,failure to find any remnants of the pier or any of the people who perished on it has been attributed to the formation of eddies or whirls that were sufficiently strong to carry down vessels by suction similar to that of the famous maelstrom off the coast of ,norway4 ,of course1 in a time of boundless excitement like that of the ,lisbon earthquake1 accounts are apt to be highly exaggerated4 ,for example1 assertions are made in many books that the water left in the harbor after the sinking of the quay was unfathomable4 ,now1 in point of fact1 the depth of this place has been measured and found to be less than #ajj fathoms4 ,when it is remembered that not one of the bodies of the people on that quay was ever again seen1 it is possible1 as ,lyell suggests1 that a deep fissure or chasm opened immediately on the ground on which the quay stood1 so that it1 together with all on it1 were dropped into the chasm1 which1 closing1 buried them deep in the earth4 ,the ,lisbon earthquake was especially noted for the extent of country affected by it4 ,humboldt estimated this area as being more than four times the size of ,europe4 ,in parts of this area immense mountain ranges1 such as the ,pyrenees1 ,alps1 etc41 were violently shaken4 ,when the size of these mountains is considered one realizes that it must have required a mighty force to shake them4 ,these shakings were so severe that they produced a deep fissure in the ground in ,france4 ,continuing towards the north the solid earth was shaken as far as the shores of the ,baltic and ,norway and ,sweden1 generally4 ,this1 of course1 included the flat country of ,northern ,germany4 ,the hot springs of ,toplitz disappeared for a time1 but1 breaking out afterwards1 discharged such quantities of muddy water that the surrounding country was inundated4 ,the waves crossed the ,atlantic1 causing high tides on the island of ,antigua1 ,barbadoes1 and ,martinique1 of the ,lesser ,antilles1 where1 instead of the usual tides of two feet1 tides of twenty feet high were observed4 ,further to the north the waves reached the eastern shores of ,north ,america1 and shook the continent as far west as the ,great ,lakes1 and spread in the ,north ,atlantic as far as ,iceland4 ,toward the south the waves affected parts of northwestern ,africa1 where much loss of life occurred in the villages some eight leagues distant from the city of ,morocco4 ,here from #h1jjj to #aj1jjj people were killed1 being swallowed up by deep fissures in the earth1 which afterwards closed on their bodies4 ,severe shocks were in many cases felt on vessels at sea4 ,in one instance1 although the vessels were at considerable distances from where the waves started1 the captains reported that the shocks were so great that on several occasions it was believed the vessel had struck a rock1 till1 on heaving the lead1 they found that they were in very deep water4 ,in another instance1 such was the shock to the vessel that the planks on the deck had their seams opened4 ,in still another case several of the sailors were thrown into the air for a distance of about one and a half feet4 ,it has been frequently observed that when great earthquakes happen1 curious changes take place in the level of the waters of lakes entirely disconnected with the ocean2 for example1 mountain lakes1 far above the level of the sea1 the water suddenly rising and then resuming its original level4 ,sometimes the waters of such lakes have suddenly disappeared1 probably being drained off through a fissure formed in the bed of the lake4 ,in such event the lake generally remains dry after the passage of the earthquake4 ,at the time of the ,lisbon earthquake it was observed that the water of ,loch ,lomond in ,scotland first rose above its ordinary1 then sank again to its usual level4 ,this difference of level is explained by ,lyell as follows3 when the earthquake waves reached the lake1 the water being unable to take the sudden shove given to it by the earthquake waves1 dashed over that side of the basin which first received the shock4 ,assuming this to be the case1 since the rise of the level in the water of ,loch ,lomond was two feet and four inches1 it is comparatively easy to calculate the speed of movement that the earthquake waves had1 when they reached this body of water4 ,calculated in this way it would seem that the waves had a speed of about twenty miles a minute4 ,but what especially characterized the ,lisbon earthquake were the great waves that were produced in the ocean4 ,besides the huge wave that entered the ,tagus1 a wave of the same height swept eastward along the southern coast of ,spain1 and the northwestern coast of ,africa4 ,at ,tangier in ,africa it swept the coast as a very high wave no less than eighteen times1 or1 in other words1 eighteen huge waves rolled in from the ocean4 ,at ,funchal1 on the ,madeira ,islands1 this wave rose fifteen feet above the high water mark4 ,many attempts have been made to explain the manner in which the great sea waves are started in earthquake movements4 ,some believe that they are due to the sudden raising or heaving up of the water1 far above ordinary level4 ,but1 as ,lyell points out1 this explanation would not be satisfactory for the waves produced in the case of the ,lisbon earthquake1 since it would fail to account for the fact that both on the coasts of ,portugal as well as on the island of ,madeira the high wave was preceded by a movement of the water toward the point of origin2 that is1 the waters moved away from ,lisbon and the ,madeira ,islands1 so as to leave the water very low at those points1 when shortly afterwards a huge wave rushed in from the sea and swept over the land4 ,earthquake waves move much more rapidly through the solid rocks of the earth's crust than through the waters of the ocean4 ,the shock transmitted through the solid earth from ,lisbon to the ,madeira ,islands took only twenty-five minutes to reach the islands1 while the waves in the ocean took about two and a half hours to cover the same distance4 ,,chapter ,,xxvii ,,the ,,earthquake ,,of ,,cutch1 ,,india1 ,,in #ahai ,cutch is one of the ,provinces of ,india lying on the western coast of ,hindostan1 east of the delta of the ,indus ,river4 ,a great earthquake occurred in this region on ,june #afth1 #ahai4 ,as indicated by the map presented in ,fig4 #dd1 by ,lyell1 the district of ,cutch lies on the coast of the ,arabian ,sea4 ,cutch is at times a peninsula1 being washed on the south and east by the ,arabian ,sea and the ,gulf of ,cutch1 and on the north by a depression known as the ,runn of ,cutch which1 during unusual tides1 is overflowed by the waters of the sea1 but for the rest of the year is dry4 ,the earthquake of ,cutch was apparently central at the town of ,bhooj1 where the destruction was extreme1 hardly a house being left standing4 ,the shock extended over a radius of about #a1jjj miles from ,bhooj1 reaching to ,khatmandoo1 ,calcutta1 and ,pondicherry4 ,at ,anjar the fort1 together with its tower and guns1 were completely ruined4 ,the shocks continued at intervals after the principal shock until ,june #bjth1 when the volcano of ,denodur is said by some to have emitted flames1 although this is denied by others4 ,great changes were produced in the eastern channel of the ,indus1 which forms the western boundary of the ,province of ,cutch4 ,the water in this inlet had become so low that it was readily fordable at low tide at ,luckput1 and was only covered with six feet of water at high tide4 ,after the earthquake it deepened at the port of ,luckput to over eighteen feet at low tide1 while in other parts of the channel the water had deepened from four to ten feet at high tide1 where before the earthquake shock it had never been deeper than from one to two feet4 ,indeed1 after these changes the inland navigation of the country again became possible after having been closed for many centuries4 ,illustration3 ,,fig4 #dd4 ,,map ,,showing ,,district ,,visited ,,by ,,the ,,earthquake ,,of ,,cutch ,,of #ahai ,the ,cutch earthquake resulted in a marked depression of the country1 especially north of ,luckput1 where the fort and village of ,sindree were so quietly sunk that the fort1 with its tower and walls1 was left projecting slightly above a body of water that not only completely covered the old site but also formed a large lake marked on the preceding map1 at ,sindree1 by the dark shading4 ,it was this change of level that deepened the eastern channel of the ,indus1 just mentioned4 ,illustration3 ,,fig #de44 ,,sindree ,,before ,,the ,,earthquake ,,of #ahai ,fig4 #de1 from ,lyell1 gives an idea of the appearance of the fort at ,sindree before the earthquake4 ,the appearance of the fort after its submergence is represented in ,fig4 #df1 where1 as will be noticed1 only the top of the tower and the walls remain above the surface of the water4 ,that the masonry was not affected either by the earthquake1 or by the inrush of waters1 is evident from the fact that the ruins were still standing in ,march1 #ahch1 as represented in the figure4 ,in heavy shading on the map in ,fig4 #dd is a large area lying in the northern part of the province known as the ,runn of ,cutch4 ,this is a flat region of about #g1jjj square miles4 ,it owes its level surface to its being the deserted or dried-up bed of a sea4 ,for the greater part of the year its bottom is dry and hard1 and is covered with a crust of salt half an inch or so in thickness4 ,illustration3 ,,fig4 #df4 ,,sindree ,,after ,,the ,,earthquake ,,of #ahai ,according to ,lyell1 from whom most of the facts concerning this earthquake have been obtained1 the ,runn of ,cutch is connected with a vast inland sea1 not only by the water driven into it through the ,gulf of ,cutch1 but also through the eastern channel of the ,indus at ,luckput4 ,these changes occur especially during the monsoon1 when the seas are high1 and especially after the heavy rains that come with these winds1 when the wet condition of the soil permits the sea water to spread rapidly4 ,traditions of the natives tend to confirm belief that ,cutch a long time ago was a true peninsula1 and that the ,runn of ,cutch was then an arm of the sea4 ,that a change of this character did occur in the ,runn of ,cutch seems to be proved by the ruins of old towns now far inland that are said to have been ancient seaports1 and as apparent evidences of this many pieces of wrought iron and ships' nails have been found in parts of the ,runn4 ,at the same time that the sinking of the land around the fort and village of ,sindree took place a considerable elevation occurred in the neighborhood4 ,immediately after the earthquake1 the people in ,sindree saw that a low hill or mound had been thrown up in a place that before had been a low and perfectly level plain4 ,they named this elevation the ,ullah ,bund1 or the ,mound of ,god1 in order to distinguish it from several embankments that had been built directly across the eastern mouth of the ,indus2 for the ,ullah ,bund had been raised by the earthquake across the same branch of the ,indus4 ,for several years after the earthquake of #ahai marked changes kept developing in the channels of the ,indus4 ,during #ahbf a large body of water entered into the eastern branch of the ,indus above the ,ullah ,bund and finally forced its way through the mound1 thus establishing a direct course to the sea4 ,the ,ullah ,bund1 being thus cut in two1 an opportunity was afforded of seeing the materials of which it was composed4 ,these were found to consist principally of clay filled with shells4 ,the opening of the river resulted in throwing such large quantities of fresh water into ,lake ,sindree that its waters were rendered fresh for several months1 but at last regained their saltiness4 ,dana states that in #ahde another earthquake occurred in this district which converted ,sindree ,lake into a salt marsh4 ,,chapter ,,xxviii ,,the ,,san ,,francisco ,,earthquake ,,of ,,april #ah1 #aijf ,about twelve minutes past five o'clock on the morning of the #ahth of ,april1 #aijf1 the inhabitants of ,san ,francisco were rudely awakened by a few frightful earthquake shocks4 ,their houses were violently shaken to and fro1 and on all sides were heard the awful crashings of falling walls1 chimneys1 and buildings1 together with the death-shrieks of those caught in the ruins4 ,rushing madly into the streets they could see on every side evidences of destruction2 for1 in almost every direction1 were heaps of fallen buildings1 still being violently shaken by the earthquake waves that rapidly passed through the solid earth4 ,huge cracks or crevices had been formed in the streets1 while the heavy rails of the trolley tracks had been bent and twisted by the mighty forces4 ,before describing in detail the great ,san ,francisco earthquake1 the location of the city and its surroundings demand consideration4 ,as can be seen from the map1 ,fig4 #dg1 ,san ,francisco is situated on the western coast of ,california1 at the northern end of a peninsula1 some twenty miles in length and about six miles in width4 ,this peninsula is formed by the magnificent ,bay of ,san ,francisco on the east1 a navigable strait called the ,golden ,gate on the north1 and the ,pacific ,ocean on the west4 ,illustration3 ,,fig4 #dg4 ,,map ,,of ,,western ,,coast ,,of ,,california ,,showing ,,position ,,of ,,san ,,francisco ,san ,francisco ,bay1 accessible by the ,golden ,gate1 is the principal harbor on the ,pacific ,coast1 and is1 indeed1 one of the most magnificent harbors in the world4 ,it is land-locked1 that is1 surrounded by a continuous land border except at its entrance through the ,golden ,gate4 ,including ,san ,pablo ,bay1 it has a length of about fifty-five miles1 and varies in breadth from three to twelve miles4 ,the entrance to the harbor1 however1 is impeded by a bar across the mouth of the ,golden ,gate1 over which there is a depth of but thirty feet of water at low tide4 ,san ,francisco has over #gej miles of streets1 #bjj miles of which are paved4 ,the city is lighted by both electricity and gas1 and has an extensive system of water-works1 the water being brought from the ,pilarcitos and ,calaveras ,creeks1 situated from twenty to forty miles respectively from the city4 ,san ,francisco is in a region where earthquakes are common4 ,it might1 therefore1 be visited at any time by a great catastrophe4 ,there have occurred between #ahej and #ahhh1 no less than #bed earthquake shocks in the ,state of ,california1 these shocks having been especially frequent in the country surrounding ,san ,francisco ,bay4 ,the most severe were the earthquake of #ahfh1 which injured ,san ,francisco2 the ,owens ,valley earthquake of #ahgb2 the ,vacaville earthquake of #ahib2 the ,mare ,island earthquake of #ahih2 and a smaller earthquake in #aijj4 ,since #aijj there was a period of rest until the #ahth of ,april1 #aijf4 ,as in the case of practically all severe earthquakes1 that which destroyed ,san ,francisco consisted of a few momentary shocks3 then all was over4 ,according to a preliminary report of the ,state ,earthquake ,commission1 appointed by the ,governor of ,california1 ,april #bast1 #aijf1 these shocks1 as recorded in the observatory at ,berkeley1 began at twelve minutes and six seconds after five ,a4 ,m41 ,pacific ,standard ,time4 ,their entire duration was only one minute and fifty seconds1 but1 as frequently happens1 there were a number of minor shocks1 following at regular intervals during the next few hours as well as the next few days4 ,while the most severe shocks were in the neighborhood of the ,peninsula of ,san ,francisco1 yet minor disturbances were felt as far north as ,coos ,bay1 ,oregon1 and as far south as ,los ,angeles1 ,california4 ,as shown by recording instruments at the seismograph station at ,washington1 ,d4 ,c41 ,sitka1 ,alaska2 ,potsdam1 ,germany2 and ,tokio1 ,japan1 a series of waves were propagated through the earth1 as well as over its periphery4 ,the damage done within the city limits was wide-reaching4 ,among the buildings almost completely destroyed were the ,city ,hall1 on which about #g1jjj1jjj had been expended1 the ,united ,states ,post ,office1 besides many business blocks1 hotels1 department stores1 theatres1 banks1 churches1 and dwelling houses4 ,amid the terrors of such a calamity it is difficult to obtain observations possessing any scientific value4 ,fortunately1 however1 there was in the city a physicist trained to observe phenomena of this character1 ,professor ,george ,davidson of the ,university of ,california4 ,like others1 he had been awakened by the first severe shock4 ,at once recognizing the nature of the phenomenon1 and desirous of obtaining the exact time of its occurrence1 he counted seconds while he ran towards the table on which he had placed his watch1 and in this way estimated that the shock occurred at twelve minutes past five in the morning4 ,the closeness of this observation is emphasized by the fact that it differed from the recorded time by only six seconds4 ,he states that the motion1 at the time of its greatest intensity1 closely resembled that of a rat vigorously shaken by a terrier4 ,the destruction caused by the earthquake was1 however1 but a small part of the total loss to the city4 ,fires were almost immediately started in the ruined houses by the fires in the kitchens and other parts of the houses1 by the ignited jets of the illuminating gas1 and1 perhaps1 especially1 by the crossing of numerous electric light wires4 ,the manner in which the woodwork and other combustible materials of the buildings were loosely tossed together by the shocks helped the quick spread of the fires1 and this1 too1 was probably greatly aided by the illuminating gas from the broken gas pipes and mains4 ,eight severe conflagrations were1 therefore1 soon raging in different parts of the doomed city4 ,what made these fires especially dangerous was the fact that the earthquake shocks had destroyed the water pipes4 ,thus the firemen were handicapped in their heroic endeavors to extinguish the flames4 ,at the time of the fire a strong wind was blowing from the northeast4 ,since the firemen were unable to check the flames1 the fire line rapidly advanced4 ,its path led towards the best residential parts of the city through portions of the mission section containing a dense population of poor people4 ,the dwellings in this latter section consisted of frame houses1 through which the flames rapidly spread4 ,there was but one way to save the city from total destruction--a free use of dynamite6 ,this was intelligently employed until the supply gave out1 when it seemed that the city was doomed to utter destruction4 ,but at the last moment1 as it were1 came a lucky change in the direction of the wind4 ,instead of blowing from the northeast1 the steady southwest winds set in1 and beat back the fire on itself1 so by ,friday1 the #ahth being ,wednesday1 it was under complete control and the rest of the city was saved4 ,illustration3 ,a ,,san ,,francisco ,,pavement ,,torn ,,by ,,the ,,earthquake ,from a ,stereograph1 ,copyright1 #aijf1 by ,underwood ,underwood ,the extent of the fire is thus described in an article in the ,outlook1 for ,saturday1 ,april #bhth1 #aijf1 as follows3 ,the turn in the direction of the fire endangered for a time the great ,ferry ,house1 at the foot of ,market ,street4 ,while the section actually destroyed is not1 geographically speaking1 much more than one-third of the city limits1 yet it is in the heart of ,san ,francisco1 and includes the chief business streets and the ,mission ,district1 inhabited by poor people1 and a large part of the so-called ,nob ,hill ,quarter1 where were the finest and costliest residences of the city4 ,another fine residence section1 ,civic ,heights1 escaped1 together with that known as the ,western ,district4 ,the unburned district1 though large in extent1 was in the nature of suburbs1 and was not closely built up1 so that estimates made1 as late as ,saturday1 declared that three-fourths of ,san ,francisco's improvements in real estate had been destroyed4 ,the burnt district was about two miles from east to west and from two to four miles from north to south1 with1 of course1 very irregular outlines4 ,naturally1 the great destruction wrought by the earthquake of ,april #ahth1 #aijf1 attracted the almost universal attention of scientific men especially interested in earthquake phenomena4 ,we are1 therefore1 able to speak authoritatively about the probable causes4 ,the great ,san ,francisco earthquake of ,april #ahth1 #aijf1 appears to have been a tectonic quake4 ,ransome1 in an article entitled1 ,the ,probable ,cause of the ,san ,francisco ,earthquake1 says3 ,the region thus amply fulfils the conditions under which tectonic earthquakes arise4 ,it is in unstable equilibrium1 and it is cut by long northwest faults into narrow blocks which are in turn traversed by many minor dislocations4 ,under the operation of the unknown forces of elevation and subsidence1 stresses are set up which finally overcome the adhesion of the opposing walls of one or more of the fault fissures2 an abrupt slip of a few inches1 or a few feet1 takes place and an earthquake results4 ,the region extending for some hundreds of miles north and south of the ,bay of ,san ,francisco may be considered as particularly susceptible to shocks on account of the number and magnitude of the faults and the evidences that these furnish of very recent slippings and the marked subsidence in the vicinity of the ,golden ,gate4 ,,chapter ,,xxix ,,some ,,other ,,notable ,,earthquakes ,it would1 of course1 be impossible within the limits of this book to attempt a description of all the remarkable earthquakes in the annals of science2 but before leaving this part of the theme a brief account of a few more among the many may be worth while4 ,jamaica1 one of the ,west ,indian ,islands1 about ninety miles south of ,cuba1 suffered a very destructive earthquake in #afib4 ,during this earthquake the ground was agitated like the waves of the sea4 ,these movements were so violent that numerous fissures were made in the ground1 as many as #cjj being formed at the same time1 rapidly opening and closing4 ,many of the inhabitants were swallowed up in these fissures4 ,in some cases1 however1 their bodies were afterward thrown out of the fissures1 along with quantities of water4 ,the ,jamaican earthquake was characterized by marked sinkings of the ground4 ,at the city of ,port ,royal1 which was then the capital1 many houses on the harbor side sank in from twenty-four to forty-eight feet of water4 ,as in the case of the earthquake at ,cutch1 many of these houses were left standing1 the chimney tops of some being seen above the water1 with their foundations and other parts apparently uninjured1 and some of them were standing at a date as late as #aghj4 ,at a little later date1 #agic1 they were mostly ruins4 ,during the ,jamaican quake a tract of land containing at least #a1jjj acres near the town was sunk1 and a wave of the sea rolled over it4 ,this wave is said by ,lyell to have carried a frigate over the roofs of the houses and left it stranded on one roof4 ,when the wave rolled back to the sea1 the weight of the frigate made it fall through the roof4 ,perhaps one of the most remarkable things about the ,jamaican earthquake was the swallowing up of several plantations1 which disappeared1 together with all their inhabitants1 their former place becoming a lake4 ,but the lake soon disappeared1 leaving a mass of sand and gravel which obliterated any least sign that dwellings and trees had once adorned the spot4 ,the forces developed during this earthquake were sufficiently powerful to make several rents in the ,blue ,mountains1 and the shock of blows on the waters of the sea killed fish by the hundred thousands so that the silver shine of their dead bodies stretched for miles and was beheld for days on the face of the deep4 ,portions of the world that have been frequently visited by mighty earthquakes1 are the coasts of ,chile4 ,on the #bdth of ,may1 #agea1 a part of the ,chilian coast near the ancient town of ,concepcion1 sometimes called ,penco1 was destroyed by an earthquake1 and the powerful earthquake waves that afterwards rushed in from the sea4 ,so complete was this destruction that the ancient harbor was rendered useless and the people had to build another town about ten miles from the coast1 so as to be beyond the reach of earthquake waves from the sea4 ,another great earthquake occurred on the coast of ,chile on the #aith of ,november1 #ahbb4 ,this shock was felt simultaneously over a distance of #a1bjj miles from north to south4 ,it reached its greatest intensity about #ajj miles north of ,valparaiso4 ,this earthquake caused a rising of the coast to a height of from three to five feet4 ,from careful examinations it appears that the area over which a permanent elevation of the country took place must have been equal to #ajj1jjj square miles1 an area equal to about half of the area of ,france1 and five-sixths that of ,great ,britain and ,ireland4 ,if we suppose1 says ,dana1 the elevation to have been only three feet on an average1 it will be seen that the mass of rock added to the continent of ,america by the movement1 or1 in other words1 the mass previously below the level of the sea1 and after the shock1 permanently above it1 must have contained fifty-seven cubic miles in bulk2 which would be sufficient to form a conical mountain two miles high 7or about as high as ,etna7 with a circumference at the base of nearly thirty-three miles4444 ,assuming the ,great ,pyramid of ,egypt1 if solid1 to weigh in accordance with the estimate before given #f1jjj1jjj tons1 we may state that the rock added to the continent by the ,chilian earthquake would have equalled more than #ajj1jjj pyramids4 ,but it must always be borne in mind that the weight of rock here alluded to constituted but an insignificant part of the whole amount which the volcanic forces had to overcome4 ,the thickness of rock between the surface of ,chile and the subterranean foci of volcanic action may be many miles or leagues deep4 ,say that the thickness was only two miles1 even then the mass which changed place and rose three feet1 being #bjj1jjj cubic miles in volume1 must have exceeded in weight #cfc1jjj1jjj pyramids4 ,the shocks of this earthquake continued from the time of its occurrence1 on ,november #aith1 #ahbb1 to the end of ,september1 #ahbc1 and even then there were scarcely two days that passed without a shock4 ,on the #bjth of ,february1 #ahce1 the same part of the world was in the throes of an earthquake that was felt nearly #a1jjj miles from north to south1 or from near the town of ,concepcion to the ,isle of ,chiloe1 and from east to west a distance of about #ejj miles1 from ,mendoza to the island of ,juan ,fernandez1 which you probably know better as ,robinson ,crusoe's ,island4 ,by this earthquake the new town of ,concepcion and several other towns were partly destroyed4 ,there were the same phenomena connected with great sea waves that are common in earthquakes of this character4 ,both this and the preceding earthquakes probably began on the bed of the ocean at some distance from the coast2 for1 in the last earthquake1 the sea retired from the ,bay of ,concepcion and vessels were grounded that had been anchored in seven fathoms of water4 ,shortly afterwards waves from sixteen to twenty feet in height rushed in from the ocean and swept over the land4 ,it is interesting in this connection to note that the volcanoes of the ,chilian ,andes were in an unusual state of activity before1 during1 and after the earthquake4 ,another characteristic of this quake was the great number of severe shocks4 ,between the day of the first great shock2 i4 e41 on ,february #bjth1 #ahce1 and ,march #dth1 there were more than #cjj severe shocks4 ,in this as in the preceding quake a notable elevation of the land near the coast occurred1 amounting to from four to five feet1 and a part of the bed of the ocean near the coast was raised permanently above the level of the sea4 ,in the description of the explosive eruption of ,krakatoa in #ahhc1 the fact was noted that the island of ,java is very frequently visited by earthquakes4 ,here a terribly severe earthquake occurred on the #eth of ,january1 #afii4 ,there were no less than #bjh shocks of great intensity4 ,considerable property in the city of ,batavia was destroyed1 and a neighboring river1 that has its head waters by a volcano near the city1 ran high and muddy and brought down multitudes of fishes that had been killed1 together with many buffaloes1 tigers1 rhinoceroses1 deer1 and other wild beasts4 ,seven hills bordering on the river sank down1 damming up the streams of the region and thereby causing wide destruction from floods4 ,during portions of the years #ahaa and #ahab an earthquake occurred in the ,united ,states1 in the ,mississippi ,valley near the town of ,new ,madrid1 ,missouri1 at the mouth of the ,ohio ,river4 ,these shocks continued almost incessantly for several months1 and were accompanied by a sinking of the ground over large areas4 ,this depressed area1 known in the neighborhood as ,the ,sunk ,country1 extended along the course of the ,white ,water ,river and its tributaries for a distance of about eighty miles from north to south1 and several miles from east to west4 ,most of it was converted into a marshy lake characterized by thousands of submerged trees4 ,the area was covered for the greater part with water to a depth of about three to four feet4 ,as the earthquake shocks continued at intervals for several months there was an ample opportunity for studying the peculiarities of the earth waves4 ,the ground rose and fell like large waves in the sea1 and after the crest of the waves had reached great heights1 the ground burst1 and threw large quantities of water1 sand1 and earth into the air4 ,illustration3 ,,fig4 #dh4 ,,new ,,zealand ,throughout the disturbed district there were numerous depressions known as sink-holes1 or irregularly shaped pits1 varying from ten to thirty yards across1 and having a depth of about twenty feet4 ,these were formed by the forcible ejection of large quantities of water mixed with sand4 ,new ,zealand has been subject to earthquake shocks for a long time1 the years #ahbf1 #ahda1 #ahdc1 #ahdh1 and #ahee being especially marked by such visitations4 ,it is a characteristic of the ,new ,zealand earthquakes that they have produced a marked change in the coast line4 ,this was particularly the case with those of #ahdh and #ahee4 ,the #bc;d of ,january1 #ahee1 an earthquake occurred that was most violent in the narrowest part of ,cook's ,strait1 a body of water separating the two principal islands that constitute ,new ,zealand2 or1 as they are called1 the ,north ,island and the ,south ,island4 ,these shocks were felt at sea by ships #aej miles from the coast4 ,the entire area shaken1 including the water1 has been estimated at three times the area of the ,british ,isles4 ,in the vicinity of the southern shores of the ,north ,island a tract of land having an area of #d1fjj square miles is believed to have been permanently raised from one to nine feet4 ,the earthquakes in ,new ,zealand are evidently of the tectonic type4 ,during that of #ahdh a rent or fissure was formed1 which1 though but eighteen inches in average width1 yet extended for a distance of sixty miles in a direction parallel to one of the mountain chains4 ,on the #cast of ,august1 #ahhf1 an earthquake of considerable intensity occurred in the ,united ,states in the neighborhood of the city of ,charleston1 ,south ,carolina4 ,the details of this earthquake were carefully studied by ,major ,dutton of the ,u4 ,s4 ,a41 and published in the ,ninth ,annual ,report of the ,united ,states ,geological ,survey of #ahhh4 ,charleston is situated on a narrow tongue of land between the ,ashley and the ,cooper ,rivers1 about seven miles from the ,atlantic ,ocean4 ,there are in this area numerous creeks connected with the drainage of these rivers4 ,as the city limits extended1 the creeks were filled in1 forming made land1 all buildings or structures erected on this land being supported by pilings4 ,it appears that the point at which the earthquakes started was situated sixteen or seventeen miles from ,charleston4 ,the earthquake shock affected a large area of the ,united ,states4 ,fig4 #di shows curved lines called isoseismal connecting places1 having the same degree of seismic intensity4 ,this map shows that these isoseimals are marked by figures or numbers from two to ten4 ,these numbers are the numbers of the ,rossi-,forel earthquake scale4 ,they indicate varying degrees of intensity1 beginning from the least intense shock which is marked as two and ending with the severest shock marked as ten4 ,there is one degree not marked on this map1 the least1 called the micro-seismic shock4 ,the shocks then increase in intensity as follows3 ,,ii4 ,extremely feeble shocks2 ,,iii4 ,very feeble shocks2 ,,iv4 ,feeble shocks2 ,v4 ,shocks of moderate intensity2 ,,vi4 ,fairly strong shocks2 ,,vii4 ,strong shocks2 ,,viii4 ,very strong shocks2 ,,ix4 ,extremely strong shocks2 ,x4 ,shocks of extreme intensity4 ,the meaning of the map presented in the accompanying figure will now become more apparent in several ways4 ,that portion numbered ten1 denoting where shocks of greatest intensity have been experienced1 clearly indicates the region just above the point where the earthquake originated4 ,beyond this is a region marked nine where the earthquake shock has decreased in intensity to the next figure on the ,rossi-,forel scale1 and then to eight and a half1 seven1 six1 five1 four1 three1 and two4 ,illustration3 ,,fig4 #di4 ,,map ,,showing ,,region ,,affected ,,by ,,the ,,charleston ,,earthquake ,,of #ahhf ,the ,charleston earthquake damaged property to a considerable extent2 for1 although comparatively few buildings were completely destroyed1 a considerable number were partially injured1 and many1 not thrown down by the shock1 had to be torn down in order to insure public safety4 ,the loss of life1 fortunately1 was comparatively small4 ,during this earthquake a number of openings called craterlets were made in the ground by the forcible ejection of large quantities of water and sand4 ,the empire of ,japan is another part of the world particularly subject to great as well as frequent earthquake shocks4 ,although ,japan is also especially noted for its volcanic activity1 its earthquakes are almost entirely of the tectonic type1 or are due to the slipping of the land at faults in the earth's crust4 ,most of these quakes occur on the bed of the ocean on the sides of a steep slope that extends down to a very deep part of the ,pacific known as the ,tuscarora ,deep4 ,on the #bhth of ,october1 #ahia1 ,japan was visited by a great quake1 generally known as the ,mino-,owaro earthquake1 from the name of the two provinces of ,mino and ,owaro in which it occurred4 ,this earthquake is correctly regarded as one of the most severe in ,japanese records4 ,originating1 as it did1 in a densely populated section1 it caused a great loss of life and property4 ,the deaths reached about #g1jjj1 while the number of houses entirely destroyed reached about #hj1jjj and those partly destroyed nearly #bjj1jjj4 ,the total area markedly affected reached #bej1jjj square kilometres1 while the area sensibly affected reached #ijj1jjj square kilometres1 or a little more than one-half the ,empire4 ,the place at which this earthquake started was situated1 not as usual on the bed of the ocean1 but on the surface of the land4 ,the first shock was the strongest and wrought the greatest havoc4 ,besides the loss of life and property1 the damage to the system of dikes or levees on the river where it passed through the delta plain near the river's mouth was heavy1 and singular in some of its features4 ,in one case1 near the city of ,nagoya1 on the ,bay near the southern coast of ,niphon1 one of these levees was lifted and shifted bodily more than sixty feet from its original position4 ,that this quake was of the tectonic type was evident from the great fault that was formed4 ,according to ,davison this fault was seventy miles in length and in places had a breadth of from two to five feet4 ,it extended from east to west1 crossing the entire width of the island4 ,another great earthquake was that which hit northeastern ,bengal and ,assam in ,india on the #abth of ,june1 #ahig4 ,according to the ,india ,geological ,survey1 by whom a careful examination of the effects produced by this quake was made1 it was1 perhaps1 the greatest quake that ever happened1 not even excepting the ,lisbon earthquake4 ,the place where the quake started appears to have been of unusual size and irregularity of outline4 ,its southern boundary was almost in the shape of a straight line extending from east to west about #bjj miles1 and covering a total area of nearly #f1jjj square miles4 ,over all this vast area the intensity of the shock was exceedingly severe4 ,the total area perceptibly shaken by the quake was about equal to #a1gej1jjj square miles4 ,that this quake was of the tectonic type became evident1 when several faults were found in the ground afterwards4 ,some of these extended twelve miles1 with a breadth at places as great as thirty feet4 ,valparaiso1 or1 as the name means1 ,vale of ,paradise1 the second largest city of ,chile and its chief seaport1 lies about ninety miles east of ,santiago1 the capital1 with which it is connected by a railroad4 ,this beautiful sea city is built at the base of a cluster of hills about #a1fjj feet above sea level4 ,on ,august #afth1 #aijf1 it was visited by an earthquake4 ,there were two distinct shocks4 ,contrary to general rule it was not the first1 but the second shock that did the most damage1 coming about ten minutes after the first4 ,as you will see from the above date the earthquake of ,valparaiso occurred shortly after the catastrophe of ,san ,francisco4 ,in a general way1 its coming was predicted by ,dr4 ,g4 ,f4 ,becker of the ,united ,states ,geological ,survey1 on ,april #aith1 #aijf1 one day after the ,san ,francisco disaster4 ,becker published an article in the ,new ,york ,tribune1 in which he argued that the severe shock at ,san ,francisco1 having occurred on one part of the earthquake region extending around the ,pacific1 would probably soon affect other portions of this region along the ,pacific coast line of this hemisphere4 ,as at ,san ,francisco fierce fires immediately started in the ruins of the houses1 but the ,valparaisans were more fortunate in having a water supply available4 ,there were very many shocks following the first two of this earthquake4 ,indeed1 during ,august #afth1 #agth1 #ahth1 and #aith1 no less than #chj were noted4 ,santiago1 situated at the foot of the ,andes1 was also considerably damaged by the same earthquake4 ,estimates1 probably conservative1 put the total of dead in both cities at #a1jjj and the number of people rendered homeless temporarily1 at #ajj1jjj4 ,,chapter ,,xxx ,,sodom ,,and ,,gomorrah ,,and ,,the ,,cities ,,of ,,the ,,plain ,the eastern border of the ,mediterranean ,sea or ,syria1 with that part of ,arabia forming the ,sinai ,peninsula and which lies between the two northern arms of the ,red ,sea1 is a region formerly characterized by extreme volcanic activity4 ,this region includes the greater part of the land promised1 according to the ,old ,testament1 to the ,children of ,israel4 ,through a large part of this region flows that historic river1 the ,jordan1 until it empties into the ,dead ,sea1 also called the ,salt ,sea1 the ,sea of the ,plain1 and by some ,lake ,asphaltites because of asphalt or bitumen so abundant on its shores4 ,this river has its source in the ,mountains of ,lebanon1 some distance north of the ,sea of ,chinnerth1 ,tiberius1 or the ,sea of ,galilee1 which empties into the ,river ,jordan4 ,as the map in ,fig4 #ej shows1 this famous1 though small river1 flows between ranges of high hills1 or low mountains1 that lie on both its eastern and western boundaries2 and these parallel ranges extend down to the ,gulf of ,akaba1 which forms the eastern boundary of the ,sinai ,peninsula4 ,the ,sea of ,galilee1 the valley of the ,jordan and the country between the ,dead ,sea and the ,gulf of ,akaba1 are all1 for the most part1 considerably below the level of the ,mediterranean or the ,red ,sea2 the ,sea of ,galilee being about #fbf feet and the ,dead ,sea #acab feet below that line4 ,illustration3 ,,fig4 #ej4 ,,syria ,that this country has been the scene of great volcanic activities is evident from the volcanic rocks found over different portions of its surface4 ,moreover1 the remains of several craters are still visible4 ,on the western banks of the ,jordan numerous dikes and streaks of basalt occur in the limestone that covers parts of the region4 ,besides there are thermal springs whose waters are at a temperature1 according to ,daubeny1 of #aad ,f4 ,then1 too1 in the neighborhood of the ,dead ,sea1 as well as in the neighborhood of the adjoining mountain ranges1 there are quantities of sulphur and asphaltum or bitumen1 while on the ,dead ,sea asphaltum is found floating in sufficient quantity to be a source of considerable revenue to the boatmen who collect it4 ,it was in this region that ,sodom1 ,gomorrah1 and other cities of the plain were situated2 cities so wicked that ,god utterly destroyed them by volcanoes and earthquakes4 ,volcanic activity was evidently common in this land of the ,bible during the times of the prophets of ,israel2 for in their poetic writings are frequent references to such phenomena--beautiful and majestic similes and metaphors derived from contemplation of live volcanoes4 ,jeremiah says3 ,behold1 ,i am against thee1 ,o devouring mountain1 saith the ,lord1 which destroyeth all the earth2 and ,i will stretch out mine hand upon thee1 and roll thee down from the rocks1 and will make thee a burnt#d mountain4 ,and they shall not take of thee a stone for a corner1 nor a stone for foundations2 but thou shalt be desolate forever1 saith the ,lord4 7,jer4 li1 #be-bf47 ,so1 too1 the prophet ,isaiah says3 ,oh that thou wouldst rend the heavens1 that thou wouldst come down1 that the mountains might flow down at thy presence6 ,as when the melting fire burneth1 the fire causeth the water to boil1 to make thy name known to thine adversaries1 that the nations may tremble at thy presence6 ,when thou didst terrible things which we look not for1 thou cameth down1 the mountains flowed down at thy presence4 7,is4 lxiv1 #a-b47 ,so1 too1 the prophet ,nahum says3 ,the mountains quake at him1 and the hills melt1 and the earth is burned at his presence1 yea1 the world1 and all that dwell therein4 ,who can stand before his indignation8 ,and who can abide in the fierceness of his anger8 ,his fury is poured down like fire1 and the rocks are thrown down by him4 7,nahum1 i1 #e-f47 ,let us now examine briefly the description ,moses gives of the destruction of ,sodom1 ,gomorrah1 and other cities of the plain4 ,this destruction occurred during the life time of ,abraham and his nephew ,lot4 ,the record says that ,god told ,abraham ,he intended to destroy them because of their wickedness4 ,then follows in the #ahth chapter of ,genesis the eloquent pleading of ,abraham for one of the doomed cities4 ,at ,abraham's earnest plea ,god promises to spare ,sodom if fifty righteous men can be found therein4 ,obtaining this respite1 ,abraham repeatedly asks further mercy for the city1 and at last receives the sacred promise that the city shall not be destroyed1 if but ten righteous people can be found there4 ,an evidence of the great wickedness of the city is seen in the fact that not even ten could be found4 ,whereupon the ,lord gives notice to ,lot that the cities were doomed and commands ,lot to leave at once with his family4 ,escape for thy life2 look not behind thee1 neither stay thou in all the plain2 escape to the mountain1 lest thou be consumed6 ,moses describes what happened as follows3 ,the sun was risen upon the earth1 when ,lot entered into ,zoar4 ,then the ,lord rained upon ,sodom and upon ,gomorrah brimstone and fire from the ,lord out of heaven2 ,and he overthrew those cities and all the plain1 and all the inhabitants of the cities1 and that which grew upon the ground4 ,but his wife looked back from behind him1 and she became a pillar of salt4 ,and ,abraham gat up early in the morning to the place where he stood before the ,lord3 ,and he looked toward ,sodom and ,gomorrah1 and toward all the land of the plain1 and beheld1 and lo1 the smoke of the country went up as the smoke of a furnace4 7,gen4 xix1 #bc-bh74 ,this is clearly the description of a volcanic eruption1 for throughout the ,bible things are described as they appear to be4 ,when ,moses speaks of brimstone and fire being rained upon ,sodom and ,gomorrah out of heaven1 he is describing the phenomenon as it would appear to one looking at it4 ,of course1 we know that in volcanic eruptions such things come to the earth through the crater of the volcano4 ,the lava is thrown high into the air1 and the hardening1 but still red hot1 ashes1 rain down on the earth from the ash cloud that forms over the mountain4 ,but1 looked at from a distance they appear to fall or be rained down from the skies4 ,in exactly the same way1 ,livy1 the ,roman historian1 tells about showers of stones that fell from heaven on ,mt4 ,albano near ,rome for two whole days during the second ,punic ,war4 ,so1 too1 even ,pliny1 who had some pretensions to be considered a naturalist1 in describing the appearance of ,mt4 ,vesuvius during the terrible eruption of ,a4 ,d4 #gi1 when ,herculaneum and ,pompeii were destroyed1 speaks of the red hot stones and ashes as falling from above4 ,so1 in reality1 they did1 although1 as in the case of the cities of the plain1 the materials forming the cloud came from the crater of the volcano below4 ,as to brimstone falling from the sky1 this is by no means an unusual occurrence during many volcanic eruptions1 since sulphur is a common material1 often thrown out of the craters of some volcanoes4 ,note also the statement that1 when ,abraham rose early in the morning and looked toward the place where ,sodom and ,gomorrah stood1 he saw the smoke of the country go up like the smoke of a furnace4 ,this was1 probably1 the smoke caused by the burning of the city1 or even by the destruction of the crops in their fields1 when ignited by the falling red hot ashes4 ,it might also have been partly due to the burning of asphalt thrown out from the fissures in the ground1 or to the showers of volcanic ashes that fell from the cloud formed during the eruption4 ,that the cities there were destroyed by a volcano far in the past appears from things outside of the ,bible proper2 for ,strabo1 the ,greek geographer1 refers to ,jewish traditions that thirteen flourishing cities were swallowed up by a volcano1 and this finds fair corroboration in the ruins along the western borders of the ,dead ,sea4 ,a writer referring to these eruptions says3 ,the eruptions themselves have ceased long since1 but the effects1 which usually succeed them1 still continue to be felt at intervals in this country4 ,the coast in general is subject to earthquakes1 and history notes several which have changed the face of ,antioch1 ,laodicea1 ,tripoli1 ,berytus1 ,tyre1 and ,sidon4 ,in #agic there happened one which spread the greatest ravages4 ,it is said to have destroyed in the valley of ,balbec upwards of #bj1jjj persons4 ,attention has already been called to the fact that the valley of the ,jordan occupies a depressed or sunken region far below the level of the ,mediterranean and the ,red ,seas4 ,it is the belief of some geologists that this depression was caused by an earthquake which accompanied the volcanic eruption that destroyed ,sodom and ,gomorrah and the cities of the plain4 ,indeed1 some contend that the present site of the valley of the ,jordan1 including the ,sea of ,tiberius and the ,dead ,sea1 is a great fissure that was made in the limestone of the valley during the time of that earthquake4 ,it would appear from the peculiar geography of this section of country that the ,jordan ,river has not always emptied into the ,dead ,sea1 but that before the time of the destruction of the ,cities of the ,plain the greater part of the country now occupied by the ,dead ,sea was a fertile valley1 and the ,jordan emptied directly into the ,red ,sea at the ,gulf of ,akaba2 that during the disturbance through changes in the valley1 or possibly by a lava stream flowing across a portion of the bed of the lower ,jordan1 or even by a huge accumulation of stones or ashes thrown out from a neighboring volcano1 the discharge of the river into the ,red ,sea was cut off1 and that in this way the waters of the rivers began to accumulate and to flow over the plain1 thus forming the basin of the ,dead ,sea4 ,there is no difficulty in accounting for the saltness of the ,dead ,sea4 ,there are large quantities of salt1 and salty matters generally1 in the volcanic rocks of the region1 but1 even if this were not so1 when a river empties into a lake with no outlet to the sea1 and which therefore loses its water by evaporation only1 the water will gradually become very salt1 since the remaining waters of such a lake contain more or less salt1 while the water they lose by evaporation contains none4 ,the waters of the ,dead ,sea are very salt1 but not the saltest in the world4 ,in every #ajj pounds of ,dead ,sea water twenty-four pounds consist of salty matters4 ,the waters of the ,great ,salt ,lake1 in ,utah1 contain eighteen per cent of salty matters4 ,lake ,van1 in eastern ,turkey1 is1 perhaps1 the saltest lake on earth1 it containing no less than thirty-three pounds of salty substances in every #ajj pounds of water4 ,daubeny1 an authority on volcanoes1 and quite competent to give an opinion concerning what is possible in this line1 describes what he believes took place1 as follows3 ,briefly then to recapitulate the train of phenomena by which the destruction of the cities might have been brought about1 ,i would suppose that the ,river ,jordan1 prior to that event1 continued its course tranquilly through the great longitudinal valley1 called ,el ,arabah1 into the ,gulf of ,akaba2 that a shower of stones and sand from some neighboring volcano first overwhelmed these places2 and that its eruption was followed by a depression of the whole of the region1 from some point apparently intermediate between the lake of ,tiberius and the mountains of ,lebanon1 to the watershed in the parallel of #cj1 which occurs in the valley of ,el ,arabah above-mentioned4 ,i would thence infer that the waters of the ,jordan1 pent-up within the valley by a range of mountains to the east and west1 and a barrier of elevated table-land to the south1 could find no outlet1 and consequently by degrees formed a lake in its most depressed portion1 which1 however1 did not occur at once1 and therefore is not recorded by ,scripture as a part of the catastrophe1 though reference is made in another passage of its existence in what was before the valley of ,siddim4 ,as regards the turning of ,lot's wife into a pillar of salt1 ,henderson1 who has carefully studied this part of the country1 remarks3 ,how natural is the incrustation of his wife on this hypothesis6 ,remaining in a lower part of the valley1 and looking with a wistful eye towards ,sodom1 she was surrounded1 ere she was aware1 by the lava1 which rising and swelling1 at length reached her1 and 7whilst the volcanic effluvia deprived her of life7 incrusted her where she stood1 so that being1 as it were1 embalmed by the salso-bituminous mass1 she became a conspicuous beacon and admonitory example of future generations4 ,,chapter ,,xxxi ,,instruments ,,for ,,recording ,,and ,,measuring ,,earthquake ,,shocks ,to attempt by the unaided senses a determination of the direction in which earthquake shocks reach any certain spot1 the velocity with which they are travelling1 their degree of intensity1 their general character1 whether horizontal or vertical1 or any peculiarities which might show them to be exceptional would be futile for more reasons than one4 ,even a skilled scientific observer1 familiar with what has already been discovered and eager to discover more1 might in the excitement of an earthquake become so excited himself as to make him unable to take reliable observations4 ,but human ingenuity has succeeded in devising delicate instruments capable of recording not only the exact time of the arrival of an earthquake shock1 but also of measuring the different parts of what may seem to be a single shock1 the direction in which the shocks reach the place1 as well as the variations of intensity in all the shocks4 ,crude instruments to do some of these things have been in use from very early times4 ,according to ,mallet among the more important of these early instruments was the following3 the instrument of ,cacciatore of ,palmero4 ,this consisted of a circular wooden dish1 about ten inches in diameter1 placed horizontally1 and filled with mercury to the brim of eight notches at equal distances apart4 ,beneath each notch was placed a small cup4 ,on the passage of the earthquake waves the vessel1 being tilted in a direction dependent on the direction in which the waves were travelling1 would cause some of the mercury to spill over into one or more of the cups1 thus indicating by its amount the intensity of the wave1 and by the particular cup or cups that were filled1 the direction in which the waves reached the place4 ,somewhat similar contrivances were of a vessel partly filled with molasses1 or other sticky liquid2 or a cylindrical tub1 the sides of which were chalked or whitewashed and filled with some colored liquid4 ,in either of these cases1 on the passage of the earthquake waves1 the vessels were tilted and showed by the height of the marks the intensity of the waves1 and by the position of the marks the direction in which the waves first reached the instrument4 ,these instruments1 though satisfactory for the study of earthquake shocks a long time ago1 when an earthquake was regarded as practically consisting of but a single shock1 or1 at the most1 of a very few shocks1 would be worthless for the study of earthquakes now1 for it is finally known that an earthquake consists of a series of many hundreds of vibrations1 differing greatly in their rapidity and intensity1 and following one another in a definite order4 ,the old forms of earthquake instruments were known as seismoscopes4 ,the word seismoscope is a compound word from ,greek consisting of the two words1 seism and scope4 ,it means literally any instrument capable of seeing1 or calling attention to1 a seism1 or earth-shake4 ,in other words1 a seismoscope is any instrument capable of calling attention only to an earth-shake4 ,of course1 neither of the rude seismoscopes just mentioned would be able to give any valuable indications of the successive shakings to which the vessel containing the viscid liquid had been subjected1 since the liquid would simply be splashed a number of times over the same parts of the vessel4 ,in order to get a record of the successive shocks another form of apparatus must be employed1 a form known as a seismograph4 ,concerning the complex character of the apparently single earthquake shock1 ,professor ,milne makes this highly interesting and picturesque statement3 ,an earthquake disturbance at a station far removed from its origin shows that the main movement has two attendants1 one which precedes and the other which follows4 ,the first of these by its characteristics indicates what is to follow1 whilst the latter1 in a very much more pronounced manner1 will often repeat at definite intervals1 but with decreasing intensity1 the prominent features of what has passed4 ,inasmuch as these latter rhythmical1 but decreasing1 impulses of the dying earthquake are more likely to result from reflection than from interference1 ,i have provisionally called them ,echoes4 ,there are many different forms of instruments known as seismographs that are capable of recording all of these vibrations1 but there is this objection to their use3 that the records appear in so tangled a form that it is practically impossible to decipher or untangle them4 ,this fact can be grasped by examining ,fig4 #ea1 which represents a record of this kind4 ,illustration3 ,,fig4 #ea4 ,,complex ,,record ,,of ,,seismograph ,it is necessary1 therefore1 to employ a modified form of instrument called a seismometer1 able not only to record all the different vibrations1 but to record them in such a manner that they can be easily recognized4 ,fig4 #eb1 for example1 shows results obtained by the use of a seismometer1 in which the different vibrations are separated1 and so recorded on a sheet of paper1 as to be readily understood4 ,such a record is called a seismogram1 and represents a long distance seismogram4 ,here the large arrow indicates the beginning of the record4 ,and herein1 as can be clearly seen1 what would appear to an observer without an instrument only a single shock1 lasting but the fraction of a minute1 in reality consists of the preliminary shake as represented in ab and bc1 the principal shake1 as represented at c1 d#a1 d#b1 and d#c1 and the final portions of the shake or the echoes of ,professor ,milne1 as represented from d#c to e4 ,illustration3 ,,fig4 #eb4 ,,long ,,distance ,,seismogram ,except in a very general way there is for present purposes no need of explaining the construction and operation of the seismometer and seismograph4 ,suffice it to say1 there are many forms of these instruments1 any of which are capable of recording the details of a passing shock4 ,the most important thing in either a seismograph or a seismometer is to obtain what is known as a steady point2 that is1 a point consisting of some object or mass that will remain practically at rest1 while everything around it1 even the support which holds it1 is affected by the earthquake4 ,it is1 of course1 not very easy to obtain a steady point1 but it can be done2 and it will be at once comprehended that if a plate or piece of paper were attached to such a steady point or mass1 and a pencil or tracer had one of its ends resting on the plate1 and its other end attached to the support that vibrates with the earth1 a tracing or record would be drawn on the plate from which the character of the motion of the end of the tracer1 and1 therefore1 of the earth1 would be marked on the plate4 ,illustration3 ,,fig4 #ec4 ,,vicentini ,,vertical ,,pendulum ,various devices have been employed for the steady points4 ,the most successful consists of a heavy mass of lead4 ,fig4 #ec represents a form of instrument invented by ,professor ,vicentini of ,italy4 ,here the steady point consists of a heavy leaden bob1 of #bjj1 #djj1 or even #ejj kilograms1 suspended by three metallic rods united above by a brass cap1 hung on a steel wire to a bracket fixed on the wall4 ,this wire may have a length as great as fifty feet4 ,illustration3 ,,fig4 #ed4 ,,vicentini ,,pendulum ,,and ,,recorder ,fig4 #ed represents the recording instrument4 ,here a tracer is provided that is capable of multiplying the motion fifty times1 or even eighty times4 ,a record is traced on a sheet of paper passing over a roller which imparts a rapid motion to a sheet so as to make sure that the different parts of the shock or vibration will be recorded on separate portions of the paper4 ,,chapter ,,xxxii ,,seaquakes ,as earthquakes are shakings of the earth's crust in places where it is uncovered by the waters of the ocean1 so seaquakes are the shakings of those portions that lie on the bed of the ocean4 ,mallet points out that the earthquake wave may start either in the interior of the continent1 or on the bed of the ocean2 that the latter place is the more common1 since on the land vents--rude safety-valves1 as it were1--are provided by the craters of the volcanoes2 that1 when earthquakes start on the ocean bed1 the impulses are conveyed in different forms of waves1 i4 e41 those through the solid earth1 those through the water1 and those through the air1 with varying sounds like bellowings and explosions1 or like the rolling of wagons over rough roads4 ,to learn when quakes occur on the sea is a much harder task1 since on the land we can use seismoscopes1 seismographs1 or seismometers to indicate1 record1 or measure the shakings of the crust1 while on the sea1 where the water is always in more or less motion and the surface so far from the ocean's bed this is impossible1 or1 rather shall it be said1 has hitherto been found so2 for that the mind of man may surmount this obstacle is not impossible to conceive4 ,to detect the wave produced by the quaking of the bed of the ocean is exceedingly difficult1 since those in very deep water are flat or possess but a small height4 ,indeed1 in the deepest parts of the ocean this height is probably to be measured only by inches instead of feet4 ,when1 however1 the waves advance towards the shore they increase in height1 and when they reach the shallows near the coast1 they begin to curl over and break1 thus creating the enormous waves mentioned so often as attending great earthquakes in the ocean4 ,during the great earthquake of ,simoda in ,japan1 #ahed1 the waters of the bay were first greatly agitated1 and then retreated1 leaving the bottom bare in places where the water was formerly thirty feet deep4 ,a wave1 thirty feet high1 then rushed in from the bay and1 climbing the land1 swept away everything in its path1 covering the town with water to the tops of the houses4 ,this monster wave then receded1 but rushed back five times4 ,in #agea1 an earthquake wave suddenly entered ,callao1 the port of ,lima1 ,peru1 sinking twenty-three vessels and driving a frigate inland1 where it was left high and dry4 ,this wave extended across the ,pacific to the ,hawaiian ,islands1 a distance of #f1jjj miles4 ,on the #acth of ,august1 #ahff1 an earthquake wave1 that started a short distance from shore1 produced a number of earthquake waves sixty feet high that reached the coast of ,peru half an hour after the principal earthquake shock4 ,these waves reached ,coquimbo1 #hjj miles distant1 in about three hours1 and ,honolulu1 on the ,sandwich ,islands1 #e1ebj miles distant1 in twelve hours1 and the coast of ,japan1 more than #aj1jjj miles distant1 on the next day4 ,le ,conte remarks that these waves would have encircled the earth1 had it not been for the barrier interposed by the ,andes4 ,another great seaquake1 known as the ,iquiqui seaquake1 during #ahfh in the same neighborhood damaged severely the towns of north ,chile and southern ,peru4 ,while1 however1 there is difficulty in readily observing the earthquake waves that form in the deep ocean1 yet such is at times the violence of an earthquake that there is no difficulty in detecting its presence1 even in deep water4 ,dr4 ,rudolph has made a careful study of the evidences of earthquakes produced in the deep sea1 from a careful examination of a great number of the logs of ships4 ,logs1 as everybody knows1 are books in which the captain or commanding officer makes careful entries of all important happenings to the vessel1 conditions of the weather and of the sea4 ,from this source ,dr4 ,rudolph obtained considerable information of much value concerning these phenomena4 ,i have already called your attention to portion of the ,atlantic ,ocean lying near the ,equator1 in the warmest part of the ocean1 between ,africa and ,south ,america1 as being a region especially liable to submarine volcanic showers4 ,while1 generally speaking1 there is nothing in this region to indicate the probability of submarine disturbance1 yet suddenly1 if a vessel happens to pass directly over the point of origin of the quake1 there ensues a great quaking or quivering4 ,loose objects on the ship begin to shake and clatter4 ,noises arise from some invisible point deep down in the ocean4 ,the disturbance grows1 the noises begin to resemble distant thunder1 the ship trembles and staggers as though it had struck rocks1 and many believe she is about to go down2 when1 as suddenly as it began1 the commotion ceases1 the noises stop1 and the ship shapes her course as calmly1 and as gallantly1 as before4 ,rudolph gives two excellent examples of seaquakes in this region1 both of which were1 doubtless1 due to submarine eruptions4 ,on the #beth of ,january1 #ahei1 as the ship ,florence was in lat4 #j #dh' ,n41 long4 #bi #af' ,w41 about ten miles ,n4 ,w4 by ,n4 from ,st4 ,paul's ,rock1 the people on board felt a sudden shock that began with a rumbling sound like distant thunder4 ,this lasted only forty seconds4 ,the glass and dishes of the vessel rattled so violently that it was feared they would be broken4 ,the shakings were so strong that several objects on the vessel were thrown down4 ,everyone believed the ship had struck on rocks4 ,the captain leaned over the taffrail in order to see the position of the reef1 but soon saw that the vessel had struck nothing1 and informed his crew it was only an earthquake shock4 ,another of the log books examined by ,rudolph was that of a ship in the same part of the ,atlantic ,ocean4 ,this record showed that suddenly on a morning1 in #ahhc1 strange noises were heard that soon increased and became not unlike the firing of great guns or the peals of distant thunder4 ,the ship vibrated as if its anchor had been suddenly let go1 and at the same time a feeling came over all the crew1 as if they had been electrified4 ,in some cases the vibrations were sufficiently severe to throw heavy objects from the deck1 as appears in an account given by a ,french geologist of a quake in the ,mediterranean off the shores of ,asia ,minor4 ,our ship was over the epicentre1#e he says1 and was so severely shaken that at first the ,admiral feared the complete destruction of the corvette4 ,he then makes the statement that the shocks which were directly upwards were so strong as to throw heavy objects in the air2 for example1 a heavy gun and its carriage4 ,while it is possible1 as ,dutton remarks1 that this incident of the heavy gun and carriage was grossly exaggerated1 yet it should not be forgotten that in the case of submarine eruptions such as that which resulted in the production of the island of ,sabrina1 an immense column of water1 weighing probably many times more than a gun and its carriage1 was observed to be shot high into the air4 ,where the seaquake is produced by a strong submarine volcanic eruption1 there is a violent commotion of the water itself1 so that a vessel passing over such a point may be greatly injured1 and1 indeed1 even destroyed4 ,such disasters1 however1 are fortunately exceedingly rare4 ,among other common effects of seaquakes is the destruction of fish already mentioned by the sudden blow to the water stunning and killing them1 just as the explosion of dynamite or other high explosives does in a lake or pond4 ,the most marked effect1 however1 of seaquakes is the starting of the great wave on the coasts of continents and islands4 ,there are certain parts of the ocean that are especially liable to seaquakes4 ,some of the more important of these1 as shown by ,rudolph's researches1 are3 ,the region already referred to in the narrowest parts of the ,atlantic ,ocean between ,africa and ,south ,america almost immediately under the equator4 ,here there are two well marked regions4 ,one is in lat4 #a ,n41 long4 #cj ,w41 where there is a submarine ridge1 the tops of which form what are known as ,st4 ,paul's ,rock4 ,the ocean here is very deep1 the slopes of the ridge descending rapidly4 ,it is on these slopes that earthquakes are very apt to occur just as they do on the steep slopes of mountain ranges4 ,the other region1 called by ,rudolph the ,equatorial ,district1 lies a little further to the east on both sides of the equator in long4 #bj ,w4 ,it appears from ,rudolph's researches that between #ahde and #ahic no less than thirty-seven seaquakes were reported in the logs of ships in the neighborhood of ,st4 ,paul's ,rock1 and between #agdg and #ahij1 in the equatorial district1 there were forty-nine seaquakes4 ,it must not be supposed1 however1 that these were all the quakes in the regions during these times1 since1 of course1 many shocks must have happened that were not felt even by vessels in the neighborhood and many more1 when this portion of the ocean was free from any craft4 ,in the ,north ,atlantic there is a portion of the ocean's bed known as the ,west ,indies ,deep4 ,here the bed is marked by great depths and by many irregularities and is1 therefore1 a region where seaquakes are common4 ,still another district is found in the ,north ,atlantic in the neighborhood of the ,azores4 ,this is the region in which the ,lisbon earthquake is believed to have started4 ,another region where seaquakes are common is in the ,pacific along the coast of ,south ,america from the equator to #de ,s4 lat4 ,here1 says ,dutton1 especially in the vicinity of the angle where the ,peruvian and ,chilian coasts meet have they been most numerous and formidable4 ,the harbors of ,pisco1 ,arica1 ,tacua1 ,iquiqui1 and ,pisago have been repeatedly subject to these destructive invasions4 ,there has been considerable discussion as to the exact manner in which the earthquake waves are set up4 ,whatever be the cause or causes1 the action must be sudden1 such as an upheaval of the bottom1 or a collapse of a large section of the ocean's bed1 with a dropping of a vast body of water4 ,or1 possibly1 a submarine volcanic eruption causes the water to lift suddenly under pressure of steam generated by escape of the lava and other hot volcanic products4 ,dr4 ,rudolph attributes earthquake waves to submarine volcanic eruptions alone4 ,it would seem1 however1 as if each one of the other things above referred to might at times be the direct cause4 ,,chapter ,,xxxiii ,,the ,,distribution ,,of ,,earthquakes ,earthquakes may occur at any part of the earth's surface1 at any time of the day1 or at any season of the year1 yet they are more frequent at certain parts1 certain hours1 certain seasons4 ,since some earthquakes are unquestionably connected with volcanic eruptions1 a map or chart of the volcanoes of the earth would also1 to a certain extent1 show the parts of the earth that are likely to be visited by earthquakes4 ,since1 however1 by far the most severe earthquakes are not directly connected with volcanoes1 but are due to sudden slips of faulted strata1 a volcanic chart would necessarily fail to indicate accurately the principal earthquake regions4 ,in the preparation of a map showing the distribution of earthquakes over the earth's surface1 ,mallet adopted the plan of colorings or tintings in such a manner that the depth of the colors would represent not only the parts shaken1 but also the relative number of times shaken1 as well as the intensity of the shocks4 ,in order to determine the depth of tint to be employed1 ,mallet divided earthquakes into the following classes according to their intensity3 ,great earthquakes1 or earthquakes of the first class2 or those in which the area affected is of great size1 in which many cities have been overthrown1 and many people killed1 and parts of the surface greatly altered4 ,intermediate earthquakes1 or those in which1 although the area affected is great1 yet the destruction of buildings1 or loss of life1 has been comparatively small4 ,minor earthquakes1 or those which1 although capable of producing small fissures in the crust1 generally leave but few or no traces of their occurrence4 ,the greatest distance to which earthquake waves of the first class extend is taken by ,mallet as being over a diameter of #a1jhj miles2 those of the second class over a diameter of about #cfj miles1 and those of the third class over a diameter of about #abj miles4 ,according to the ,rossi ,forel scale already given1 earthquake shocks are divided according to their relative intensity into ten separate classes1 viz43 ,i4 ,the micro-seismic2 ,,ii4 ,the extremely feeble2 ,,iii4 ,the very feeble2 ,,iv4 ,the feeble2 ,v4 ,the moderately intense2 ,,vi4 ,the fairly strong2 ,,vii4 ,the strong2 ,,viii4 ,the very strong2 ,,ix4 ,the extremely strong2 ,x4 ,shocks of extreme intensity4 ,an earthquake map prepared according to ,mallet's scale would show a greater depth of color or tint in the neighborhood of the volcanic districts of the earth and especially in the neighborhood of the mountain regions1 where tectonic quakes are most frequent4 ,oceanic areas would be left almost untinted1 not because earthquakes do not occur on the bed of the ocean1 but because of the difficulty of observing such earthquakes at great distances from the land4 ,so far from earthquakes being absent on the bed of the ocean it is most probable that they are more frequent there than elsewhere4 ,prepared in this way1 ,mallet's map would show a preponderance of earthquakes along the borders of the continents1 especially along the ,great ,circle of ,fire on the borders of the ,pacific ,ocean4 ,dutton as well as some others assert that the ,great ,circle of ,fire on the shores of the ,pacific has in reality no existence2 that1 instead of there being a continuous region of volcanoes1 there is in reality nothing more than a considerable number of volcanoes arranged in groups along the borders of this ocean1 but separated by spaces containing no marked volcanic activity4 ,we do not think this a tenable position1 since it is well known that volcanoes lie along great lines of fissures at different points or openings which are kept open by subsequent volcanic activity1 while the remaining portions are closed soon afterwards2 and1 moreover1 in parts of these so-called non-volcanic regions1 there are probably extended regions of extinct volcanoes4 ,since the time of ,mallet many maps have been made to show the distribution of earthquakes4 ,among the best of such is that by ,m4 de ,montessus de ,ballore4 ,some idea of the great amount of work required for the preparation of ,montessus' map may be formed when one learns that the catalogue of earthquakes collected by him for this purpose included for the years #ahhj to #aijj1 #aca1bib quakes4 ,de ,montessus' earthquake map divides the grand divisions of the earth into numerous sub-divisions1 too numerous1 indeed1 for even brief description in a work of this kind4 ,from the map he thus laboriously prepared ,de ,montessus drew the following general conclusions3 #a4 ,the parts of the earth that are most apt to be shaken by earthquakes are those which possess the greatest differences of relief between their highlands and lowlands1 and that in such regions the most pronounced earthquakes are found on the steepest slopes4 #b4 ,earthquakes are most common along those parts of the crust that are thrown up in huge wrinkles1 or mountain ranges1 whether these masses be above the level of the sea or are covered by it4 ,illustration3 ,,fig4 #ee4 ,,davison',s ,,earthquake ,,map ,,of ,,japan #c4 ,earthquakes are more common in mountainous districts than in plains4 ,but not all mountains are characterized by earthquakes nor are all plains free from them4 ,sometimes the plain at the base of the mountain appears to be especially liable to shocks1 probably by reason of slips along faults at these points4 ,the great mountain ranges of the world are generally characterized by unequal slopes1 the long gentle slope facing the interior of the continents1 and the short1 abrupt slopes being turned towards the coast4 ,now1 ,montessus points out that volcanoes are the most frequent on the short1 abrupt slopes4 ,in some cases1 however1 where the long slopes are the roughest1 it is these slopes that are most frequently shaken4 ,the beds of the ocean that lie along rapidly descending lines1 especially when they lie on the borders of large mountain ranges1 are especially liable to earthquakes4 ,dr4 ,charles ,davison has made a map of the earthquakes of ,japan in which he had adopted the plan of representing the origin or centres of earthquakes by a series of contour lines like those employed on topographical maps4 ,the advantage of this type of map over that employed by ,mallet is just this3 ,davison's earthquake map of ,japan in which the active volcanoes are marked by dots1 and the earthquakes by contour lines surrounding the points of origin1 discloses the interesting fact that here the positions of the volcanoes and the earthquake centres coincide1 since the mountainous districts where the active volcanoes are numerous are singularly free from earthquakes4 ,this can be seen from an inspection of ,fig4 #ee4 ,,chapter ,,xxxiv ,,the ,,causes ,,of ,,earthquakes ,earthquakes occurred long before man appeared on earth4 ,it is natural1 therefore1 that our early ancestors1 experiencing these unwelcome phenomena1 vaguely endeavored to explain their causes4 ,these early attempts at explanation have in many cases been of an exceedingly fanciful character4 ,the ancient ,mongolians and ,hindoos declared that earthquakes are due to our earth resting on a huge frog and that they occur whenever the frog scratches its head4 ,in ,japan1 where earthquakes are very common1 the ignorant people even at a much later day declared that there exists in the depth of the sea an immense fish which1 when angry1 dashes its head violently against the coast of the island1 thus making the earth tremble4 ,this is1 doubtless1 the biggest fish-story extant4 ,another folk-lore explanation in ,japan attributes the cause of the tremblings of the earth to a subterranean monster whose head lies in the north of the island of ,hondo1 while his tail lies between the two principal cities4 ,the shaking of his tail causes earthquakes4 ,fantastic and foolish as these explanations are1 it is worthy of note that the first of the ,japanese explanations shows no little observation on the part of the people1 since it locates the starting-points of earthquakes as being not on the land1 but on the bottom of the sea4 ,in point of fact1 nearly all the great earthquakes in ,japan seem to start somewhere between the coasts of the islands on the sea-bottom that leads down to a very deep part of the ,pacific known as the ,tuscarora ,deep4 ,many years ago nearly everyone believed that earthquakes were caused solely by the forces that produce volcanic eruptions2 that all earthquakes1 whether in the neighborhood of active volcanoes1 or at great distances therefrom1 were to be regarded solely as volcanic in their origin4 ,it is now recognized that the most severe and far-reaching earthquakes have no immediate connection with volcanic explosions1 but are due to the sudden slippings of the earth's strata over lines of faults2 or1 in other words1 earthquakes are most frequently of the tectonic type4 ,at the present time there is unfortunately much difference in opinion as to the exact cause of earthquakes4 ,by this is not meant the immediate cause1 but the ultimate cause4 ,as to the immediate cause1 practically all are agreed that quakes of volcanic origin are to be traced to the same forces that produce volcanic eruptions1 while quakes of tectonic origin are due directly to the slipping of the strata along the faults4 ,but when inquiry is instituted as to the nature of the forces that cause the volcanic eruptions1 or that produce such an alteration of the strata as permits them afterwards to slip and thus jar the earth1 there is much difference of opinion4 ,as can be seen from a few quotations of well-known authorities1 only two kinds of earthquakes exist2 namely1 volcanic earthquakes and tectonic earthquakes4 ,dana1 for example1 while acknowledging that small earthquakes may be caused by the sudden falling of large rock masses into cavities in the crust of the earth1 says3 ,but true earthquakes come1 for the most part at least1 from one or the other of the following sources of disturbance4 #a4 ,vapors suddenly produced1 causing ruptures and friction4 #b4 ,sudden movements or slips along old or new fractures4 ,earthquakes due to the former of these methods are common about volcanoes1 and at the ,hawaiian islands shakings that are destructive over the island of ,hawaii at the moment of some of the more violent eruptions1 do not often affect the island of ,oahu1 a depth of #ejj fathoms of water1 the least depth between the two islands1 being sufficient to stop off the vibrations4444 ,earthquakes of the second mode of origin may occur in all regions1 volcanic or not4 ,they have their origin mostly in the vicinity of mountain regions1 where old fractures most abound4 ,the vibrations may begin in a slip of a few inches1 in fact2 but where there has been a succession of slips1 up and up from #aj1jjj feet or more1 as in the ,appalachian1 earthquakes of inconceivable volcanic activity must have resulted4 ,dana points out that volcanoes stand on lines of fractures in the openings of which their existence began and that1 during geological time1 slips up or down these fractures have occurred1 producing earthquakes and possibly starting eruptions4 ,prestwich1 a well-known ,english geologist1 speaks very decidedly concerning the causes of earthquakes3 ,for my own part1 ,i am disposed to share the belief expressed by ,dana that the tension or pressure1 by which the great oscillations or plications of the earth's crust have been produced1 have not entirely ceased2 and that this is generally the most probable cause of earthquakes4 ,the uplifting of the great continental tracts and mountain ranges must have always left the interior of the crust in a state of unstable equilibrium1 and any slight slide or settling along an old fracture1 or in highly disturbed and distorted strata1 would be attended by an earthquake shock4 ,in volcanic areas the removal of the large volumes of molten rock from the interior to the surface must produce settlements and strains which might also result in some of these minor earthquakes to which volcanic districts are so subject4 ,where we have the two conditions combined1 as they are in the ,andes in ,south ,america1 these earthquake phenomena are1 as we should expect1 developed on the grandest and widest scale4 ,geikie1 the ,scotch geologist1 says3 ,various conceivable causes may1 at different times and under different conditions1 communicate a shock to the subterranean regions4 ,such as the sudden flashing into steam of water in the spherodial state1 the sudden condensation of steam1 the explosion of a volcanic outpour1 the falling in of the roof of a subterranean cavity1 or the sudden snap of deep-seated rocks subjected to prolonged and intense stress4 ,sir ,charles ,lyell1 the great ,english geologist1 holds the following views concerning the origin of earthquakes4 ,he speaks as follows in his ,principles of ,geology3 #a4 ,the primary cause of the volcanoes and the earthquakes are to a great extent the same1 and connected with the development of heat and chemical action at various depths in the interior of the globe4 #b4 ,volcanic heat has been supposed by many to be the result of the high temperature which belonged to the whole planet when it was in a state of igneous fusion1 a temperature which they suppose to have been always diminishing and still to continue to diminish by radiation into space4444 ,the powerful agency of steam or aqueous vapor in volcanic eruptions leads us to compare its power of propelling lava to the surface with that which it exerts in driving up water in the pipe of an ,icelandic geyser4 ,various gases also1 rendered liquid by pressure at great depths1 may aid in causing volcanic outbursts and in fissuring and convulsing the rocks during earthquakes4 ,major ,clarence ,edward ,dutton1 ,u4 ,s4 ,a41 an acknowledged authority on seismology1 speaks as follows3 ,thus far1 then1 we have two causes of earthquakes which are apparently well sustained3 7#a7 the downthrows1 which have often been observed to be accompanied by earthquakes1 and 7#b7 volcanic action4 ,but neither of them have been shown to be connected with more than a comparatively small number4 ,much the greater part of the earthquakes still require explanation1 and the indications are manifold that some of them are produced by some cause yet to be stated4 ,he acknowledges1 however1 this unknown cause may be traceable to volcanic agency4 ,to quote him in full3 ,it remains now to refer to the possibility that many quakes whose origin is unknown1 or extremely doubtful1 may1 after all1 be volcanic4 ,this must be fully admitted1 and1 indeed1 it is in many cases highly probable4 ,evidences that volcanic action has taken place in the depths of the earth without visible1 permanent results on the surface abound in ancient rock exposures4 ,formations of great geological age1 once deeply buried and brought to daylight by secular denudations1 show that lavas have penetrated surrounding rock-masses in many astonishing ways4 ,sometimes they have intruded between strata1 lifting or floating up the overlying beds without any indication of escaping to the surface4 ,sometimes the lava breaks across a series of strata and finds its way into the partings between higher beds4 ,or it forces its way into a fissure to form a dike which may never reach the surface4 ,in one place a long arm or sheet of lava has in a most surprising and inexplicable manner thrust itself into the enveloping rock-mass1 and in the older or metamorphic rocks these offshoots or apophyses cross each other in great numbers and form a tangled network of intrusive dikes4 ,in other places the intruded lava has formed immense lenticular 7lense shaped7 masses 7laccolites71 which have domed up the overlying strata into mountain masses4 ,these intrusions1 almost infinitely varied in form and condition1 are often1 in fact usually1 inexplicable as mechanical problems1 but their reality is vouched for by the evidence of our senses4 ,what concerns us here is the great energy which they suggest and their adequacy to generate in the rocks those sudden1 elastic displacements which are the real initiatory impulses of an earthquake4 ,they assure us that a great deal of volcanic action has transpired in past ages far under ground1 which makes no other sign at the surface than those vibrations which we call an earthquake4 ,koto1 the celebrated ,japanese student of earthquakes1 and a member of the ,earthquake ,investigation ,committee appointed by the ,japanese ,government for studying the great ,mino-,owaro earthquake1 in ,japan1 #ahia1 is properly regarded as an authority on earthquakes4 ,living1 as he does1 in a country where earthquakes and volcanic eruptions are of almost daily occurrence1 he has had abundant opportunity for studying these phenomena1 especially in connection with the ,seismological ,institute of ,japan4 ,he speaks as follows3 ,to make clear once for all my own standpoint1 ,i may say plainly that the chain of volcanoes and the system of mountains of the non-volcanic earthquake1 appear to me to have very intimate and fundamental relations with the so-called tectonic line4 ,mallet regards earthquakes that can be directly traceable to volcanic origin as unsuccessful efforts on the part of nature to establish volcanoes4 ,he speaks concerning this matter as follows3 ,an earthquake in a non-volcanic region may1 in fact1 be viewed as an uncompleted effort to establish a volcano4 ,the forces of explosion and impulse are the same in both2 they differ only in degree of energy1 or in the varying sorts and degrees of resistance opposed to them4 ,there is more than a mere vaguely admitted connection between them1 as heretofore commonly acknowledged--one so vague that the earthquake has been often stated to be the cause of the volcano 7,johnson1 ',phy4 ,atlas1' ,geology1 page #ba71 and more commonly the volcano the cause of the earthquake1 neither view being the expression of the truth of nature4 ,they are not in the relation to each other of cause and effect1 but are both unequal manifestations of a common force under different conditions4 ,before closing this chapter on the causes of earthquakes it may be well to state briefly the explanations that have been suggested by those who hold that the earth is solid and cold throughout its entire mass1 except that in the neighborhood of volcanic districts there are limited areas situated only a comparatively few miles below the surface where the rocks are highly heated4 ,professor ,mallet suggested that the source of heat for these local areas of melted rocks was to be found in the enormous mechanical force that is developed by the crushing of the strata in the earth's crust4 ,the principal objection to ,mallet's theory is to be found in the fact that1 for this heat to be available for the melting of rocks1 it must be produced rapidly1 and not spread out over long periods of time4 ,moreover1 there would appear to be no other way to account for the production of the great force required to effect the crushing of the earth's strata save on the assumption of a highly heated interior still cooling and contracting4 ,in his ,aspects of the ,earth ,shaler has suggested an hypothesis that may be regarded to a certain extent as explaining how heat1 slowly generated1 might be blanketed1 or prevented from escaping and so possibly reaching a temperature sufficiently high to melt the materials in portions of the interior not far below the surface of the earth4 ,we thus see that in the water imprisoned in the deposits of the early geological ages and brought to a high temperature by the blanketing action of the more recently deposited beds1 we have a sufficient cause for the great generation of steam at high temperatures1 and this is the sole essential phenomenon of volcanic eruptions4 ,we see also by this hypothesis why volcanoes do not occur at points remote from the sea1 and why they cease to be in action soon after the sea leaves their neighborhood4444 ,the foregoing considerations make it tolerably clear that volcanoes are fed from deposits of water contained in ancient rocks which have become greatly heated through the blanketing effects of the strata which have been laid down upon them4 ,the gas which is the only invariable element of volcanic eruptions is steam2 moreover1 it is the steam of sea-water1 as is proven by analysis of the ejections4 ,it breaks its way to the surface only on those parts of the earth which are near to where the deposition of strata is lifting the temperature of water contained in rocks by preventing1 in fact1 the escape of the earth's heat4 ,another very common theory is that of chemical action1 or the heat produced by the oxidation of various substances inside the earth1 such1 for example1 as iron pyrites1 a compound of iron and sulphur4 ,when ,sir ,humphrey ,davy discovered metallic sodium and it was found that this material1 when thrown on water1 possessed the power of liberating intense heat1 the discovery was welcomed by geologists as affording a possible explanation of the cause of volcanoes and earthquakes4 ,it may be said generally concerning chemical action as the source of the earth's interior heat1 that the chief objection against it is the fact that such heat is liberated too slowly to result in the production of a very high temperature4 ,this objection does not exist in the case of such substances as metallic sodium1 since here the heat is rapidly developed and is sufficient in amount to fuse the substances produced4 ,but in the lava produced in such great quantities as it is in volcanic districts there must be liberated at the same time large quantities of gaseous hydrogen4 ,now1 although hydrogen is1 as we have already seen1 sometimes given off with the gases that escape from volcanic craters1 yet the quantity which escapes is so small that this theory of volcanic activity has been practically abandoned4 ,quite recently1 however1 among the various chemical substances that are produced under the extremely high temperatures of the electric furnace have been found1 or formed1 a number of curious substances such as calcium carbide1 calcium silicide1 barium silicide1 etc41 that possess the property of becoming highly heated on coming in contact with water4 ,now it is an interesting fact that the hydrogen and other gases which are given off by the action of water on these substances are absorbed in large quantities by the materials themselves1 so that the objection of the absence of hydrogen and similar gases in the craters of the volcanoes would not be quite as objectionable as in the case of such substances4 ,of course1 it is impossible to say whether such substances as calcium carbide1 etc41 actually exist inside the earth's crust1 yet1 as has been pointed out1 the principal condition necessary for their formation1 i4 e41 a high temperature1 existed at times long after the earth1 assuming the correctness of the nebular hypothesis1 was separated from the nebulous sun4 ,there still remains to be discussed the most curious of all possible causes that have been suggested for the presence of the local heated areas at comparatively short distances below the earth's crust2 namely1 radio-activity4 ,in #ahif1 ,henri ,becquerel1 a ,frenchman1 while investigating the power of the ,x-rays1 when passing through certain substances1 to produce phosphorescence1 or causing the substances to shine in the dark1 made the extraordinary discovery that some of the salts of uranium possess the power of emitting a peculiar radiation closely resembling the ,x-rays1 that is able to pass through substances opaque to ordinary light as well as to affect photographic plates4 ,but the most extraordinary part of this discovery was that the salts of uranium apparently possess the power of giving out this radiation continuously without being exposed to the sun's rays4 ,this peculiar property was called radio-activity1 and was shortly afterwards found to be present in many other substances besides uranium1 and notably so in two newly discovered elements known as polonium and radium4 ,now it has been suggested that if there existed somewhere beneath the earth's crust in these locally heated areas1 large quantities of radio-active substances1 these regions would at last become highly heated1 and in this way likely to produce volcanoes and earthquakes4 ,it would not1 however1 seem that this is probably their true cause4 ,from what has just been said it is clear how exceedingly difficult it has become to explain the source of the earth's interior heat when the fact of the earth's original highly heated condition is denied4 ,we are1 therefore1 disposed with ,russell to believe1 as stated in the first part of this volume1 that the ultimate cause of both volcanoes and earthquakes is to be found in the gradual cooling of an originally highly heated globe1 and that the greater part of the interior is still in a highly heated condition1 hot enough to be melted but yet in a solid condition by reason of the great pressure to which it is subjected4 ,,chapter ,,xxxv ,,earthquakes ,,of ,,the ,,geological ,,past--,,cataclysms ,there were numerous volcanoes in the geological past2 therefore1 since volcanic eruptions are generally attended by earthquake shocks1 it follows that during that remote past the earth has been violently shaken by earthquakes4 ,indeed1 if we assume1 as we believe to be the case1 that the cause of earthquakes is correctly to be traced to an originally heated globe which is gradually cooling1 it follows that the earth was necessarily subject to great earthquakes almost from the time when it began to cool4 ,but to establish as a fact the occurrence of an earthquake at so remote a time in the earth's history is far more difficult than to detect the occurrence of a volcano at that time4 ,while the earthquake shocks may produce fissures in the earth's crust1 and may be accompanied by great changes of level1 yet the great time that has elapsed between such occurrences and the present would permit the various geological agencies that are at work either to cover these fissures completely1 or completely to remove by erosion1 or in other similar ways1 the rocks in which they occurred4 ,it is different in the case of a volcano2 for the volcanic craters are in many cases still left standing1 and then there are the voluminous sheets of lava that have spread over great areas of the earth1 as well as numerous volcanic cones4 ,besides1 there are thousands of square miles of surface that have been covered1 often to great depths1 by deposits of volcanic dust thrown out at one time or another from the craters of the then active volcanoes4 ,i am sure you will acknowledge that any force capable of causing great cracks or fissures in the earth's crust1 must1 while doing this1 have produced violent shakings of the earth4 ,great cracks or fissures are to be found in the rocks of all the geological formations4 ,these are a record of the earthquakes that must have attended these convulsions4 ,and there is plenty of evidence to show that the earth's crust has been torn into these fissures in places deep down below the present surface2 for1 by the action of water1 many of these portions have been uncovered so that these great cracks or fissures which have been afterwards filled with a molten rock that has hardened can be seen in the great dikes that still remain4 ,but there are still other evidences of the existence of earthquakes during the geological past4 ,there are found in the different strata of the earth's crust fossil remains of the plants and animals that lived on the earth long before the creation of man4 ,by a careful study of these fossils we know positively the kinds of animals and plants that lived on the earth1 in its waters1 or in its atmosphere1 when these strata were being deposited4 ,it is in this way possible for a geologist to trace the life of the earth and its development as it is written on the great book of which the earth's different strata form the separate pages4 ,now1 a careful study of the earth's fauna and flora during the geological past1 shows1 beyond any question1 that occasionally great changes have occurred in the earth2 for1 here and there1 during different times1 we find that certain species of animals and plants have completely disappeared1 to be followed1 after certain intervals1 by entirely different species4 ,it is evident1 therefore1 that changes have occurred that have made it impossible for the animals and plants that formerly lived on the earth to exist under the changed conditions4 ,these occurrences are known to geologists as exterminations1 catastrophes1 or cataclysms4 ,they are also sometimes called revolutions1 for they mark a more or less complete wiping-out of the animals living at the time they occurred4 ,if you will try to think you will readily understand how great a catastrophe must be1 that would be able to wipe out or completely destroy an entire race of animals4 ,you have doubtless read with astonishment the terrible catastrophe that accompanied the eruption of ,krakatoa1 especially at the loss of life and property caused by the great waves that were set up in the ocean1 but far reaching as these losses were they have nevertheless affected but a limited portion of the earth4 ,the plain truth is even more stupendous1 for catastrophes of the geological past appear to have been so far-reaching and powerful as to affect the whole surface of the earth1 and to have annihilated entire races of animals and plants as if they had never existed4 ,geologists are all practically agreed that there are only two ways in which such exterminations of the earth's life could have been caused1 and these are changes in the earth's climate1 or the starting of waves in the sea by great earthquakes4 ,in the sea2 for it must be borne in mind that in the geological past the greater part of the earth's surface was covered by water1 and the land areas were comparatively small and low1 so that waves created by earthquakes might easily have overwhelmed the entire land surface4 ,of course1 it is fair to suppose that in many cases these exterminations may have been caused by sudden changes of climate1 such as would naturally have resulted from any change in the direction of hot ocean currents which formerly flowed from the equator to the poles4 ,the appearance of a fairly large mass of land in the central parts of the ocean might readily have turned aside the hot ocean currents that formerly swept over the polar regions1 thus greatly lowering the earth's average temperature in these regions4 ,but it seems probable that the principal cause of the destruction of life in the geological past was produced by earthquake waves in the sea1 sweeping over the continents4 ,let us1 therefore1 examine two of the earth's principal geological revolutions or cataclysms2 namely1 that which occurred at the close of an early geological time known as the ,palaeozoic1 and that which occurred at the end of a geological time intermediate between the ,palaeozoic time or the time of ancient life1 called the ,mesozoic time1 and the ,cenozoic time1 or the time immediately preceding the present time4 ,these two revolutions are called by ,dana1 the ,post-,palaeozoic1 or ,appalachian ,revolution1 and the ,post-,mesozoic ,revolution4 ,both were characterized by the making of great mountain systems1 and were1 therefore1 especially liable to repetitions of tremendous earthquakes that must have produced enormous waves in the ocean4 ,palaeozoic time1 says ,dana1 closed with the making of one of the great mountain ranges of ,north ,america--the ,appalachian1 besides ranges in other lands1 and in producing one of the most universal and abrupt disappearances of life in geological history4 ,so great an event is properly styled a revolution4 ,towards the close of the ,palaeozoic time immense disturbances of the earth's crust occurred during the uplifting of the ,appalachian ,mountain ,system4 ,one may1 perhaps1 form some faint idea of the immensity of the forces at work1 from the fact that there were great faults produced by the uplifting of the lands attended with displacement amounting to #aj1jjj or #bj1jjj feet or more2 that in parts of southwestern ,virginia there were flexure faults #ajj miles in length4 ,as to the probability of the extensive exterminations that have occurred during these times being produced by earthquake waves1 ,dana speaks thus3 ,the causes of the extermination are two4444 7#a7 a colder climate4444 7#b7 earthquake waves produced by orogenic movements 7movements producing mountain ranges74 ,if ,north ,america from the west of the ,carolinas to the ,mississippi ,valley can be shaken in consequence of a little slip along a fracture in times of perfect quiet 7the allusion here to the ,charleston earthquake1 in #ahhf71 and ruin mark its movements1 incalculable violence and great surgings of the ocean should have occurred and been often repeated during the progress of flexures1 miles in height and space1 and slips along newly opened fractures that kept up their interrupted progress through thousands of feet of displacements4444 ,under such circumstances the devastation of the sea-border and the low-lying land of the period1 the destruction of their animals and plants1 would have been a sure result4 ,the survivors within a long distance of the coastline would have been few4 ,the same waves would have swept over ,european land and seas1 and there found coadjutors for new strife in earthquake waves of ,european origin4 ,these times of catastrophe may have continued in ,america through half of the following ,triassic period2 for fully two thirds of the ,triassic period are unrepresented by rocks and fossils on the ,atlantic border4 ,coming now to the ,post-,mesozoic revolution this period was marked by the making of the greatest of the ,north ,american mountain systems4 ,dana points out that this revolution affected the summit region of the ,rocky ,mountains over a broad belt probably as long as the western side of the continent4 ,this great belt of mountain-making extended from the ,arctic regions through ,north ,america1 probably paralleled by like work1 of equal extent1 in ,south ,america1 but on a more eastern line4 ,the disappearance of species1 says ,dana1 at the close of ,mesozoic time was one of the two most noted in all geological history4 ,probably not a tenth part of the animal species of the world disappeared at the time1 and far less of the vegetable life and terrestrial ,invertebrates2 yet the change was so comprehensive that no ,cretaceous species of ,vertebrate is yet known to occur in the rocks of the ,american ,tertiary1 and not even a marine ,invertebrate4 ,in tracing the causes of these disappearances1 ,dana points out that1 perhaps1 the principal cause was a decrease in the temperature of the ocean1 since the destructions were limited in large measure to marine life4 ,he regards1 however1 the other most probable cause as traceable to earthquake waves2 for the making of a great mountain range along the entire length of the continent resulted in displacements of the rock formations along lines hundreds of miles in length4 ,such displacements must have been attended by a succession of earthquakes of unusual violence1 causing the destruction by sudden shocks beneath1 and resulting1 directly and indirectly1 in waves sweeping over the continent4 ,since at this time the land was still low for the greater part1 the huge waves must have repeatedly swept over the greater part of the land1 leaving only the smaller species of animals and the vegetation4 ,it is evident1 therefore1 that during the geological past earthquakes occurred that were probably vastly greater than any that have occurred on the earth during more recent times4 ,,chapter ,,xxxvi ,,the ,,kimberly ,,diamond ,,fields ,,and ,,their ,,volcanic ,,origin ,the elementary substance carbon occurs in three forms1 i4 e41 charcoal1 graphite1 and the diamond4 ,the commonest form of carbon is to be found in charcoal1 as well as in bituminous coal1 anthracite coal1 and lignite4 ,graphite1 also known as plumbago1 or black lead1 is the substance you have seen so often in the lead of pencils4 ,the diamond1 as every one knows1 is the highly prized precious stone that sparkles so brightly in the light1 and is so hard that it is capable of scratching almost any other substance4 ,diamonds are found in various parts of the world4 ,we are now interested in them1 however1 only as they occur in certain parts of the world1 as in the great ,kimberly diamond fields in ,southern ,africa4 ,dr4 ,max ,bauer in his book on precious stones says that the discovery of diamonds in ,south ,africa was made by a traveller named ,o',reilly1 who1 in #ahfg1 saw a child sitting in the house of a ,boer named ,jacobs1 playing with a shining stone4 ,jacob's farm was a short distance south of the ,orange ,river near ,hopetown4 ,this stone proved to be a diamond weighing some twenty-one and three-tenths carats and was afterwards sold for #b1ejj4 ,the incident led to the discovery and consequent development of the ,kimberly diamond fields4 ,without going into a description of the different deposits in which diamonds are found1 it will suffice to say that in the ,kimberly district the diamonds occur distributed through the materials that fill peculiar funnel-shaped depressions called pipes which extend vertically downward to unknown depths4 ,the rock that fills a pipe consists of an entirely different material from that in which the pipe occurs4 ,the upper extremity of the pipe is generally slightly elevated above the general surface for a few yards4 ,the pipes vary in diameter from twenty to #gej yards1 diameters of from #bjj to #cjj yards being quiet common4 ,in #ahib1 the diamond-bearing material found in the pipes of the ,kimberly mines had been excavated vertically downwards a distance of #a1bfa feet1 without any signs of its being exhausted4 ,now1 the materials which fill the pipe of the great ,kimberly mine are practically the same in all the mines in the neighborhood4 ,at the upper part of the pipe the materials show the action of weathering by exposure to the air4 ,here the ground is of a yellowish color4 ,below1 the materials have a blue color4 ,according to ,bauer the diamond-bearing material that fills the upper part of the pipe consists of a soft1 sandy material of a light yellow color1 known to diamond miners as yellow ground1 or yellow stuff4 ,in the case of the ,kimberly mine1 the yellow ground has a thickness of about sixty feet4 ,below it the material has a blue color and is known as the blue ground4 ,this latter material possesses the character of a volcanic tuff1 which is a hardened clay4 ,it is of a green or bluish green color and has the appearance of dried mud that holds or binds together numerous irregular1 tough1 and sometimes rounded fragments of a green or bluish black serpentine4 ,the diamonds are found near the surface in the yellow ground1 as well as downwards through the blue ground4 ,it was at one time thought that most of the diamonds existed in the yellow ground1 and that they would soon disappear entirely at short distances below where the blue ground began4 ,under this belief some of the most valuable claims changed hands at prices far below their true value4 ,it was soon found1 however1 that large and valuable stones existed in the blue ground1 and1 indeed1 this ground has never been mined to a depth below where valuable diamonds appear4 ,the diamonds occur in very small quantities spread through the yellow and blue grounds4 ,the following statement by ,bauer will show this3 ,a striking illustration of their sparing occurrence is furnished by the fact that in the richest part of the richest mine1 namely1 in the ,kimberly mine1 they constitute only one part in #b1jjj1jjj1 or #j4jjjje of the blue ground4 ,in other mines the proportion is still lower1 namely1 one part in #dj1jjj1jjj1 a yield which corresponds to five carats per cubic yard of rock4 ,of course1 you will desire by this time to know the manner in which the pipes of the diamond mines of ,south ,africa have become filled with the diamond-bearing rocks1 and particularly what diamonds have to do with a book on volcanoes and earthquakes4 ,dr4 ,emil ,cohen1 who has made a study of these regions1 regards the pipes as volcanic vents or chimneys1 and that the materials filling the pipes have been brought up from below by volcanic forces4 ,he says3 ,i consider that the diamantiferous ground is a product of volcanic action1 and was probably erupted at a comparatively low temperature in the form of an ash saturated with water and comparable to the materials ejected by a mud volcano4 ,subsequently new minerals were formed in the mass1 consequent on alterations induced in the upper part by exposure to atmospheric agencies1 and in the lower by the presence of water4 ,each of the crater-like basins1 or1 perhaps1 more correctly1 funnels1 in which alone diamonds are now found1 was at one time the outlet of an active volcano which became filled up1 partly with the products of eruption and partly with ejected material which fell back from the sides of the crater intermingled with various foreign substances1 such as small pebbles1 or organic remains of local origin1 all of which became imbedded in the volcanic tuff4 ,the substance of the tuff was probably mainly derived from deep-seated crystalline rocks1 of which isolated remains are now to be found1 and which are similar to those which now crop out at the surface1 only at a considerable distance from the diamond fields4 ,these crystalline rocks from which the diamonds probably took their origin1 were pulverized and forced up into the pipes by the action of volcanic forces1 and imbedded in this eruptive material1 these diamonds either in perfect crystals or in fragments are now found4 ,so far as the volcanic origin of the diamonds of the ,kimberly diamond fields is concerned1 ,cohen's theory has been generally accepted with the following modifications3 that the pipes were not filled by a single volcanic eruption1 but by successive eruptions1 and that in the case of the ,kimberly mine1 the pipes contain the results of as many as fifteen successive eruptions4 ,there has1 however1 been another and more important modification proposed to ,cohen's theory1 which is far more probable4 ,it will be noticed that ,cohen's theory regards the action of the volcanic eruption as only serving to bring fragments of a deep-seated mother rock that contained the diamonds up from below with the material that fills the pipe4 ,now1 ,prof4 ,carvill ,lewis proposes the following very important change in ,cohen's theory3 that the blue ground does not consist of fragmentary material or tuff1 but was forced up from below in the pipe in a molten mass and consolidated on cooling4 ,in other words1 the blue ground is filled with an ordinary igneous rock that was solidified in place in the vent or pipe4 ,in the great ,kimberly mines the surface of the pipe is divided into numerous separate claims1 each consisting of a small square lot4 ,there are so many of these claims in the ,kimberly mine that its surface is honey-combed by numerous square pits4 ,the work is done largely by native ,kaffirs employed there since the '#gj's4 ,as the material was removed from the pit1 the adjoining claims were separated from each other by high vertical walls4 ,at a later date1 in order to remove the material and separate the lots1 high staging provided with ropes and hauling machinery was erected4 ,the number of these ropes is now so great that the mine has the appearance of a huge cobweb4 ,a very extensive series of investigations has been made at a comparatively recent date by ,prof4 ,henri ,moissan of ,france on various chemical products that are obtained under the influence of the high temperatures of the electric furnace4 ,when a powerful electric current is caused to pass through a highly refractory material1 that is to say1 a material difficult to fuse1 such as carbon1 it raises it to an extremely high temperature4 ,a still higher temperature can be obtained by causing a powerful current to flow between two carbon rods that are first brought into contact1 and then gradually separated from each other1 just as they are in the ordinary arc lights employed for lighting the streets of our cities4 ,in the latter way a temperature that is estimated as high as #c1ejj ,c4 7#f1ccb ,f471 can be readily obtained4 ,under these very high temperatures some very curious chemical products have been obtained in electric furnaces4 ,these furnaces consist of small chambers made of highly refractory materials closely surrounding the incandescent carbon1 or the carbon voltaic arc4 ,among some of the most curious of these products are artificially produced diamonds4 ,moissan1 however1 was not the first to produce diamonds artificially4 ,as soon as ,lavoisier had experimentally shown that the chemical composition of the diamond and carbon are the same1 efforts were made to convert charcoal into diamonds1 and ,despretz1 as early as #ahdi1 by means of the combined influence of a powerful burning glass1 the oxyhydrogen blowpipe1 and the carbon voltaic arc obtained a very high temperature4 ,he claims by this temperature to have been able to change carbon into a few microscopic diamonds4 ,it is quite possible1 in the light of later investigations1 that ,despretz may have been mistaken in his belief that he had actually produced diamonds2 but whether this be so or not1 he was certainly one of the pioneers in this early transformation of charcoal4 ,theoretically1 all that would be required in order to change the non-crystalline form of carbon into the diamond1 would be to subject the carbon to a temperature sufficiently high to fuse it and then permit it slowly to crystallize4 ,could this be done1 there should be no trouble in transforming any amount of coal into any equal amount of diamonds4 ,but the transformation is by no means as simple as might be supposed4 ,it is not that the temperature of the carbon cannot be raised to its point of fusion1 but that as soon as a certain temperature has been reached1 the carbon1 instead of fusing or melting1 is suddenly volatilized or turned into vapor4 ,there is no doubt that this is done4 ,thousands of feet of carbon rods are volatilized every night in the arc lamps of our cities1 but the trouble is that this carbon vapor so formed1 when cooled1 or condensed1 is not converted into the exceedingly hard1 clear1 crystalline diamond1 but into the soft1 dull black graphite or plumbago4 ,now the process adopted by ,moissan in order to cause volatilized carbon1 or carbon vapor1 to condense in the form of crystalline diamonds was practically as follows3 he placed pieces of pure carbon inside a very strong steel tube1 such1 for example1 as would be formed by boring a short cylindrical hole in a piece of strong thick steel1 and placing a small quantity of carbon inside the tube so formed4 ,closing the open end of the tube by means of a tightly fitting screw plug1 he volatilized the carbon inside the tube4 ,the steel1 tube1 and plug formed an electric furnace1 for1 as soon as he passed an electric current through it1 the temperature at once became high enough to volatilize the carbon4 ,under these circumstances the carbon vapor was subjected to great pressure owing to the limited space in which it was liberated4 ,as soon as this mass of dense vapor had been formed1 he seized the steel tube with a pair of furnace tongs1 and plunged it below the surface of cold water in a bucket4 ,of course1 as the hot tube suddenly chilled1 there was a great shrinking in the walls of the furnace1 so that the already compressed carbon vapor was subjected to a still greater pressure which possibly liquified it4 ,of that1 however1 we cannot speak definitely4 ,this1 however1 can safely be asserted1 that when the tube was broken open a confused mass of small crystals was found inside1 some of which1 on examination with the microscope1 were found to consist of small crystals of two forms of diamonds1 namely1 the black diamond1 or carbonado1 and the regular crystallized diamond4 ,moissan made a great number of experiments for producing diamonds in this way1 and succeeded in forming some very beautiful1 though microscopic1 diamonds4 ,what may be said to characterize especially ,moissan's experiments was the comparatively great number of diamonds1 so small as to be scarcely distinguishable under the microscope4 ,the high temperature to which the materials inside the tube were exposed resulted in the production of numerous minute crystals of different minerals4 ,in order to get rid of as many of these as possible ,moissan adopted the plan of subjecting the material to the action of powerful solvents1 such as sulphuric acid1 aqua regia1 or a mixture of sulphuric and nitric acid1 and hydrofluoric acid4 ,these acids destroyed most of the minute crystals of other minerals1 but left the minute crystals of diamonds unaffected4 ,now it will be observed that the theory proposed by ,prof4 ,carvill ,lewis as to the probable origin of the diamonds of the ,kimberly mines bears a wonderfully close resemblance to the method adopted by ,moissan for the production of artificial diamonds1 since it supposes the diamonds to have been formed by the sudden cooling or chilling within the pipe of various molten materials brought up from great depths by the volcanic forces4 ,if this be true1 then besides the comparatively large crystallized and perfect diamonds found in the blue ground of the ,kimberly mines1 there should also be found large quantities of microscopic diamonds1 just as are found in ,moissan's electric furnaces1 in which he produced artificial diamonds4 ,moissan1 considering this1 obtained a specimen of the blue ground from the ,kimberly diamond pipe and on subjecting it to the action of the different solvents before named1 found in the mass that was left undissolved a great number of microscopic diamonds4 ,it would seem1 therefore1 that there is no reasonable doubt but that the ,kimberly diamond fields had their diamonds produced by the sudden chilling in the volcanic pipes of molten materials brought from great depths by the force of volcanic eruption4 ,,chapter ,,xxxvii ,,the ,,fabled ,,continent ,,of ,,atlantis ,besides the sudden changes of level that frequently occur during earthquake shocks there are gradual changes of level that take place very slowly throughout long periods of time4 ,these are believed to be due to the warpings produced by the cooling of an originally highly heated globe4 ,it is not true1 therefore1 that the earth's surface is fixed1 or that its land and water areas remain always the same4 ,on the contrary1 what is land at one time is water at another time1 and so1 too1 water areas may become changed into land areas4 ,for the most part these changes go on so slowly as not to be noticeable in an ordinary lifetime4 ,indeed1 in some cases1 they are so extremely gradual that ,methuselah himself might have gone to his grave in ignorance of their progress4 ,let us briefly note a few well-known gradual changes of level4 ,one of the most extensive of these is the sinking of an immense area1 over #f1jjj miles in diameter1 that covers a large part of the bed or floor of the ,pacific ,ocean4 ,it is an easy matter to observe the gradual changes of level on the coasts1 since the old water line can be at once found1 but it is very difficult to detect such changes in the bed of the ocean1 hidden as it is by a covering of water4 ,yet many things that seem impossible to the uninitiated are readily solved by those familiar with physical science4 ,little signs1 meaningless to others1 are easily read1 and these prove beyond doubt the gradual sinking of the ocean's bed4 ,it was once believed that the coral polyps or animalcul from the hard1 bony skeletons of which coral reefs are formed1 could live at the greatest depths of the ocean4 ,these minute animals were1 therefore1 generally credited with filling up the deep ocean1 in certain places1 and converting it into dry land1 and poetic philosophers were pleased to point to their indefatigable labors as an object lesson to the slothful4 ,but these charming1 though fallacious1 ideas were rudely overthrown by the sounding line and the drag-net4 ,it had long been known that pieces of coral rock were brought up by dredging apparatus from the bottom of the ocean at all depths1 but it was eventually shown that such pieces of coral rock never contained living animalcul1 when brought from water at greater depths than from #ajj to #abj feet4 ,it puzzled scientific men no little at first to explain this apparent inconsistency4 ,if the coral polyp could not live in water at greater depths than from #ajj to #abj feet1 how could the presence of coral rock at a depth of thousands of feet be explained8 ,happily1 however1 this problem was solved by the great naturalist1 ,charles ,darwin1 who showed that coral islands can only be formed in parts of the ocean whose beds are sinking at the same gradual rate at which the coral rock is being deposited4 ,the presence1 therefore1 of coral islands on the bed of the ,pacific1 as well as along parts of its coasts1 are1 to scientific men1 as good indications of its gradual sinking as if such facts had been written in the clearest language4 ,but there are other instances of gradual changes of level besides the bed of the ,pacific4 ,about #fjj miles along the coast of ,greenland1 from ,disco ,bay1 near lat4 #fi ,n41 south to the ,firth of ,igaliko1 lat4 #fj #dc' ,n41 the bed of the ocean has been slowly sinking through #djj years4 ,old buildings and islands have been covered by the waters1 so that fishermen have been compelled to provide new poles for their boats4 ,as ,sir ,charles ,lyell remarks3 ,in one place the ,moravian settlers have been obliged more than once to move inland the poles upon which their large boats are set1 and the old poles still remain beneath the water as silent witnesses of the change4 ,besides these gradual changes of level there are many others1 but only one more need be cited3 the gradual movements of the coasts of ,north ,america between ,labrador and ,new ,jersey that are rising in some places1 and sinking in other places4 ,the evidences of these gradual changes of level are sometimes of such a character that he who runs may read them4 ,one of the most interesting is1 perhaps1 that of the old ,roman temple of ,jupiter ,serapis1 at ,pozzuli1 on the borders of the ,mediterranean4 ,this temple1 when completed1 was #abd feet in length and #aae feet in width4 ,its roof was supported by forty-six columns1 each forty-two feet in height1 and five feet in diameter4 ,only three of these columns are now standing4 ,they give1 however1 unquestionable evidence of having been submerged for about half their height4 ,nor1 indeed1 is the evidence wanting that this submergence continued a considerable time2 for1 while the lower twelve feet of the columns remain smooth and unaffected1 yet1 for a distance of nine feet above this portion1 they have been perforated by various stone-boring mollusks of a species still living in the ,mediterranean4 ,this witnesses that the columns1 when submerged1 were buried in mud for twelve feet1 and surrounded by water nine feet deep4 ,according to ,dana1 the pavement of the temple is still under water4 ,the fact that another pavement exists below it shows that these changes of level had occurred before the temple was deserted by the ,romans4 ,it appears1 that1 prior to #ahde1 a gradual sinking of this part of the coast had been going on1 but that since then there has ensued a gradual rising4 ,the evidences of these gradual changes of level in the land and water surfaces of the earth cannot be doubted by even the most skeptical4 ,again and again has the dry land disappeared below the surface of the waters of the ocean4 ,again and again1 the ocean's bed has been raised to the surface and been converted into dry land4 ,suppose we attempt to follow one of the latter movements4 ,we will imagine an extensive area to have slowly appeared above the ocean4 ,in due process of time this land surface1 which we will assume to have continental dimensions1 gradually becomes covered with plant and animal life4 ,if it remains above the water for a sufficient length of time1 its simple plants and animals acquire more and more complex forms1 so as to make it difficult to detect any traces of the original species from which they have descended1 or1 more correctly1 ascended4 ,moreover1 where favorable conditions exist1 the continent becomes peopled with men1 who gradually advance from barbarism to semi-barbarism and eventually become a most highly civilized nation1 sending to different parts of the world colonies1 who carry with them the language and religious customs of the land of their birth4 ,but1 a sudden or paroxysmal change of level occurs4 ,the highly developed and densely populated region is suddenly swept out of existence and completely covered by the waters of the ocean until1 in a few thousand years1 all traces of its existence have so completely disappeared that but few1 if any1 can be found willing to acknowledge it ever had an existence4 ,such1 it is claimed1 was the fate of the fabled ,continent of ,atlantis4 ,it will1 therefore1 be interesting to endeavor briefly to review its past history and to read some of the things that have been written about this part of the world1 which appears in the opinion of some of the ancients to have actually existed4 ,references to ,atlantis have been made by various early writers4 ,solon1 the great ,athenian lawgiver1 who flourished #fjj years ,b4 ,c41 began a description of this place in verse4 ,this description was never completed4 ,at a later date one of ,solon's descendants1 ,plato1 who lived about #djj ,b4 ,c41 prepared a description of ,atlantis1 giving in detail its location1 the general character of its surface1 a description of its principal city1 and the civilization of its inhabitants1 as well as a brief reference to its sudden destruction4 ,in another place this record of ,plato will be given in full4 ,it will suffice now to quote briefly what he says concerning its location4 ,there was an island situated in front of the straits which you call the ,columns of ,heracles 7,straits of ,gibraltar74 ,the island was larger than ,libya and ,asia put together1 and was the way to other islands1 and from the island you might pass through the whole in the opposite continent1 for this sea which is within the ,straits of ,heracles is only a harbor1 having a narrow entrance1 but that other is the real sea1 and the surrounding land may most truly be called a continent4 ,now1 in the island of ,atlantis1 there was a great and wonderful empire1 which had ruled over the whole island and several others1 as well as over part of the continents2 and1 besides these1 they subjected the parts of ,libya within the ,columns of ,heracles as far as ,egypt1 and of ,europe as far as ,tyrrhenia4 ,the vast power1 thus gathered into one1 endeavored to subdue at one blow our country and yours1 and the whole of the land which was within the straits1 and then1 ,solon1 your country shone forth1 in the excellence of her virtues and strength1 among all mankind1 for she was the first in courage and military skill1 and was the leader of the ,hellenes4 ,and when the rest fell off from her1 being compelled to stand alone1 after having undergone the very extremity of danger1 she defeated and triumphed over the invaders1 and preserved from slavery those who were not yet subjected1 and freely liberated all the others who dwelt within the limits of ,heracles4 ,but afterwards1 there occurred violent earthquakes and floods1 and in a single day and night of rain1 all your warlike men in a body sunk into the earth1 and the island of ,atlantis in a like manner disappeared1 and was sunk beneath the sea4 ,and that is the reason why the sea in those parts is impassable and impenetrable1 because there is such a quantity of shallow mud in the way2 and this was caused by the subsidence of the island4 7,plato's ,dialogues1 ii1 #eag1 ,timus74 ,but besides ,solon and ,plato there are other ancient writers who refer to the lost island of ,atlantis4 lian1 in his ,varia ,historia1 lib4 iii1 chap4 xvii1 states that ,theopompos1 who flourished #djj ,b4 ,c41 refers to an interview between ,midas1 ,king of ,phrygia1 and ,sielus1 in which the latter speaks of a great continent larger than ,asia1 ,europe1 and ,libya together that existed in the ,atlantic4 ,proclus quotes a statement from an ancient writer1 who speaks about the islands of the sea beyond the ,pillars of ,hercules 7,straits of ,gibraltar74 ,marcellus1 in a book on the ,ethiopians1 refers to seven islands in the ,atlantic whose inhabitants preserve legends of a greater island 7possibly ,atlantis71 that had dominion over the small islands4 ,diodorus ,siculus asserts that the ,phoenicians discovered a large island in the ,atlantic beyond the ,pillars of ,hercules several days' sail from the coast of ,africa4 ,homer1 ,plutarch1 and other ancient writers1 refer to several islands in the ,atlantic situated several thousand stadia from the ,pillars of ,hercules4 7,a stadium was a ,greek measure of length equal to #fjj feet4 ,it was equal to one-eighth of a ,roman mile1 or #fbe ,roman feet47 ,ignatius ,donnelly1 in his book1 called ,atlantis1 the ,ante-,diluvian ,world1 claims that ,plato's description of ,atlantis which has generally been regarded as imaginary1 was1 on the contrary1 historic2 that the prehistoric continent of ,atlantis was the cradle of the human race2 that here man reached his highest civilization2 that ,atlantis was the site of the ,garden of ,eden1 the ,gardens of the ,hesperides1 the ,elysian ,fields1 as well as ,olympus2 that1 under the forms of the gods and goddesses of the ancient ,greeks1 the ,phoenicians1 the ,hindoos1 and the ,scandinavians1 are related the stories of the kings1 queens1 and heroes of ,atlantis4 ,much that has been claimed for the lost continent can hardly be regarded in any other light save that of imagination4 ,for example1 it has been asserted that it was from ,atlantis that the colonies were sent out that peopled the coast countries of the ,gulf of ,mexico1 of parts of the valley of the ,mississippi1 the basin of the ,amazon1 the western coasts of ,south ,america1 parts of ,europe1 the shore lands of the ,mediterranean ,sea1 the coasts of ,europe1 including the ,caspian and the ,black ,seas1 and even of parts of ,africa4 ,it has also been asserted that this mighty nation of ,atlantis carried the worship of the sun to ,egypt1 which was one of its first colonies1 and1 therefore1 the civilization of ,egypt was but an offshoot of prehistoric ,atlantis4 ,but it will be reasonably objected that1 if such a mass of land ever existed in the ,north ,atlantic1 some evidences should still be found on the bed of the ocean4 ,even though great periods of time have elapsed since the disappearance of ,atlantis1 some traces of its former existence should still remain on the floor of the ocean4 ,are there any evidences of an old land mass on this part of the floor of the ,atlantic8 ,the answer is unmistakable4 ,deep-sea soundings show beyond question that there still exists in the ,north ,atlantic in the region where ,atlantis is said to have been located a submarine island1 the summits of which appear above the waters in the ,azores and the ,canary ,islands4 ,this submarine island has been traced southwest over the bed of the ocean for a distance of several thousand miles with a breadth of fully #a1jjj miles4 ,toward the south there is connected with it another submarine island1 the summits of which reach above the surface in the islands of ,ascension1 ,st4 ,helena1 and ,tristan d',acunha4 ,but the testimony of the submarine islands extends further than this4 ,according to a number of careful soundings it appears that the bed of these parts of the ocean1 instead of being characterized by a comparatively level surface due to the gradual accumulation of silt1 possesses1 to a great extent1 the peculiarly sculptured surfaces which are only produced by exposure for a long time to the atmosphere4 ,other facts might be adduced to show that some time during the first appearance of man on the earth there was a large land mass connecting the ,eastern and ,western ,continents4 ,these facts include the wonderful resemblances existing between the plants and animals of the ,eastern and ,western ,continents1 the close resemblances of the myths and legends of the races of the ,eastern and ,western ,continents1 as well as the identity of their religious ideas1 and the close similarity of their language so far as relates to certain fundamental ideas4 ,these facts all point unquestionably to the existence of some large land mass between the two continents1 and to this extent to throw light on the probable existence of prehistoric ,atlantis4 ,,chapter ,,xxxviii ,,plato',s ,,account ,,of ,,atlantis ,the following is a translation of ,plato's record in full3 ,critias4 ,then listen1 ,socrates1 to a strange tale1 which is1 however1 certainly true1 as ,solon1 who was the wisest of the seven sages1 declared4 ,he was a relative and great friend of my great-grandfather1 ,dropidas1 as he himself says in several of his poems1 and ,dropidas told ,critias1 my grandfather1 who remembered1 and told us1 that there were of old great and marvellous actions of the ,athenians1 which have passed into oblivion through time and the destruction of the human race--and one in particular1 which was the greatest of them all1 the recital of which will be a suitable testimony of our gratitude to you4444 ,socrates4 ,very good2 and what is this ancient famous action of which ,critias spoke1 not as a mere legend1 but as a veritable action of the ,athenian ,state1 which ,solon recounted8 ,critias4 ,i will tell an old-world story which ,i heard from an aged man2 for ,critias was1 as he said1 at that time nearly ninety-years of age1 and ,i was about ten years of age4 ,now the day was that day of the ,apaturia which is called the registration of youth2 at which1 according to custom1 our parents gave prizes for recitations1 and the poems of several poets were recited by us boys1 and many of us sung the poems of ,solon1 which were new at the time4 ,one of our tribe1 either because this was his real opinion1 or because he thought that he would please ,critias1 said that1 in his judgment1 ,solon was not only the wisest of men but the noblest of poets4 ,the old man1 ,i well remember1 brightened up at this1 and said smiling3 ,yes1 ,amynander1 if ,solon had only1 like other poets1 made poetry the business of his life1 and had completed the tale which he brought with him from ,egypt1 and had not been compelled1 by reason of the factions and troubles which he found stirring in this country when he came home1 to attend to other matters1 in my opinion1 he would have been as famous as ,homer1 or ,hesiod1 or any poet4 ,and what was that poem about1 ,critias8 said the person who addressed him4 ,about the greatest action which the ,athenians ever did1 and which ought to have been most famous1 but which1 through the lapse of time and the destruction of the actors1 has not come down to us4 ,tell us1 said the other1 the whole story1 and how and from whom ,solon heard this veritable tradition4 ,he replied3 ,at the head of the ,egyptian ,delta1 where the river ,nile divides1 there is a certain district which is called the district of ,sais1 and the great city of the district is also called ,sais1 and is the city from which ,amasis the king was sprung4 ,and the citizens have a deity who is their foundress3 she is called in the ,egyptian tongue ,neith1 which is asserted by them to be the same whom the ,hellenes called ,athene4 ,now1 the citizens of this city are great lovers of the ,athenians1 and say that they are in some way related to them4 ,thither came ,solon1 who was received by them with great honor2 and he asked the priests1 who were most skilful in such matters1 about antiquity1 and made the discovery that neither he nor any other ,hellene knew anything worth mentioning about the times of old4 ,on one occasion1 when he was drawing them on to speak of antiquity1 he began to tell about the most ancient things in our part of the world--about ,phoroneus1 who is called 'the first1' and about ,niobe2 and1 after the ,deluge1 to tell of the lives of ,deucalian and ,pyrrha2 and he traced the genealogy of their descendants1 and attempted to reckon how many years old were the events of which he was speaking1 and to give the dates4 ,thereupon1 one of the priests1 who was of very great age1 said3 ',o ,solon1 ,solon1 you ,hellenes are but children1 and there is never an old man who is an ,hellene4' ,solon1 hearing this1 said1 ',what do you mean8' ',i mean to say1' he replied1 'that in mind you are all young2 there is no old opinion handed down among you by ancient traditions1 nor any science which is hoary with age4 ,and ,i will tell you the reason of this3 there have been1 and there will be again1 many destructions of mankind arising out of many causes4 ',there is a story which even you have preserved1 that once upon a time ,phathon1 the son of ,helios1 having yoked the steeds in his father's chariot1 because he was not able to drive them in the path of his father1 burnt up all that was upon the earth1 and was himself destroyed by a thunder-bolt4 ,now1 this has the form of a myth1 but really signifies a declination of the bodies moving around the earth1 and in the heavens1 and a great conflagration of things upon the earth recurring at long intervals of time3 when this happens1 those who live upon the mountains and in dry and lofty places are more liable to destruction than those who dwell by rivers or on the sea-shore2 and from this calamity the ,nile1 who is our never-failing savior1 saves and delivers us4 ',when1 on the other hand1 the gods purge the earth with a deluge of water1 among you herdsmen and shepherds on the mountains are the survivors1 whereas those of you who live in cities are carried by the rivers into the sea2 but in this country neither at that time nor at any other does the water come up from below1 for which reason the things preserved here are said to be the oldest4 ,the fact is1 that wherever the extremity of winter frost or of summer sun does not prevent1 the human race is always increasing at times1 and at other times diminishing in numbers4 ,and whatever happened either in your country or in ours1 or in any other regions of which we are informed--if any action which is noble or great1 or in any other way remarkable has taken place1 all that has been written down of old1 and is preserved in our temples2 whereas you and other nations are just being provided with letters and the other things which ,states require2 and then1 at the usual period1 the stream from heaven descends like a pestilence1 and leaves only those of you who are destitute of letters and education2 and thus you have to begin all over again as children1 and know nothing of what happened in ancient times1 either among us or among yourselves4 ',as for those genealogies of yours which you have recounted to us1 ,solon1 they are no better than the tales of children2 for1 in the first place1 you remember one deluge only1 whereas there were many of them1 and1 in the next place1 you do not know that there dwelt in your land the fairest and noblest race of men which ever lived1 of whom you and your whole city are but a seed or remnant4 ,and this was unknown to you1 because for many generations the survivors of that destruction died and made no sign4 ,for there was a time1 ,solon1 before that great deluge of all1 when the city which now is ,athens1 was first in war1 and was preminent for the excellence of her laws1 and is said to have performed the noblest deeds1 and to have had the fairest constitution of any of which tradition tells1 under the face of heaven4' ,solon marvelled at this and earnestly requested the priest to inform him exactly and in order about these former citizens4 ',you are welcome to hear about them1 ,solon1' said the priest1 'both for your own sake and for that of the city2 and1 above all1 for the sake of the goddess who is the common patron and protector and educator of both our cities4 ,she founded your city a thousand years before ours1 receiving from the ,earth and ,hephstus the seed of your race1 and then she founded ours1 the constitution of which is set down in our sacred registers as #h1jjj years old4 ,as touching the citizens of #i1jjj years ago1 ,i will briefly inform you of their laws and of the noblest of their actions2 and the exact particulars of the whole we will hereafter go through at our leisure in the sacred registers themselves4 ,if you compare these very laws with your own1 you will find that many of ours are the counterpart of yours1 as they were in the olden time4 ',in the first place1 there is the caste of priests1 which is separated from all the others2 next there are the artificers1 who exercise their several crafts by themselves1 and without admixture of any other1 and also there is the class of shepherds and that of hunters1 as well as that of husbandmen2 and you will observe1 too1 that the warriors in ,egypt are separated from all the other classes1 and are commanded by the law only to engage in war4 ,moreover1 the weapons with which they are equipped are shields and spears1 and this the goddess taught first among you1 and then in ,asiatic countries1 and we among the ,asiatics first adopted4 ',then1 as to wisdom1 do you observe1 what care the law took from the very first1 searching out and comprehending the whole order of things down to prophecy and medicine 7the latter with a view to health72 and out of these divine elements drawing what was needful for human life1 and adding every sort of knowledge which was connected with them4 ,all this order and arrangement the goddess first imparted to you when establishing your city2 and she chose the spot of earth in which you were born1 because she saw that the happy temperament of the seasons in that land would produce the wisest of men4 ',wherefore the goddess1 who was a lover both of war and of wisdom1 selected1 and first of all settled that spot which was the most likely to produce men likest herself4 ,and there you dwelt1 having such laws as these and still better ones1 and excelled all mankind in all virtue1 as became the children and disciples of the gods4 ,many great and wonderful deeds are recorded of your ,state in our histories2 but one of them exceeds all the rest in greatness and valor2 for these histories tell of a mighty power which was agressing wantonly against the whole of ,europe and ,asia1 and to which your city put an end4 ',this power came forth out of the ,atlantic ,ocean1 for in those days the ,atlantic was navigable2 and there was an island situated in front of the straits which you call the ,columns of ,heracles3 the island was larger than ,libya and ,asia put together1 and was the way to other islands1 and from the island you might pass through the whole of the opposite continent which surrounded the true ocean2 for this sea which is within the ,straits of ,heracles is only a harbor1 having a narrow entrance1 but that other is a real sea1 and the surrounding land may be most truly called a continent4 ,now1 in the island of ,atlantis there was a great and wonderful empire1 which had rule over the whole island and several others1 as well as over parts of the continent2 and1 besides these1 they subjected the parts of ,libya within the ,columns of ,heracles as far as ,egypt1 and of ,europe as far as ,tyrrhenia4 ',that vast power1 thus gathered into one1 endeavored to subdue at one blow our country and yours1 and the whole of the land which was within the straits2 and then1 ,solon1 your country shone forth1 in the excellence of her virtue and strength1 among all mankind1 for she was the first in courage and military skill1 and was the leader of the ,hellenes4 ,and when the rest fell off from her1 being compelled to stand alone1 after having undergone the very extremity of danger1 she defeated and triumphed over the invaders1 and preserved from slavery those who were not yet subjected1 and freely liberated all the others who dwelt within the limits of ,heracles4 ,but afterward there occurred violent earthquakes and floods1 and in a single day and night of rain all your warlike men in a body sunk into the earth1 and the island of ,atlantis in like manner disappeared1 and was sunk beneath the sea4 ,and that is the reason why the sea in those parts is impassable and impenetrable1 because there is such a quantity of shallow mud in the way2 and this was caused by the subsidence of the island4' 7',plato's ,dialogues1' ii1 #eag1 ,timus47444 ,but in addition to the gods whom you have mentioned1 ,i would specially invoke ,mnemosyne2 for all the important part of what ,i have to tell is dependent on her favor1 and if ,i can recollect and recite enough of what was said by the priests1 and brought hither by ,solon1 ,i doubt not that ,i shall satisfy the requirements of this theatre4 ,to that task1 then1 ,i will at once address myself4 ,let me begin by observing first of all that nine thousand was the sum of years which had elapsed since the war which was said to have taken place between all those who dwelt outside the ,pillars of ,heracles and those who dwelt within them4 ,this war ,i am now to describe4 ,of the combatants on the one side the city of ,athens was reported to have been the ruler1 and to have directed the contest2 the combatants on the other side were led by the kings of the islands of ,atlantis1 which1 as ,i was saying1 once had an extent greater than that of ,libya and ,asia2 and1 when afterwards sunk by an earthquake1 became an impassable barrier of mud to voyagers sailing from hence to the ocean4 ,the progress of the history will unfold the various tribes of barbarians and ,hellenes which then existed1 as they successively appear on the scene2 but ,i must begin by describing1 first of all1 the ,athenians as they were in that day1 and their enemies who fought with them2 and ,i shall have to tell of the power and form of government of both of them4 ,let us give the precedence to ,athens4444 ,many great deluges have taken place during the nine thousand years1 for that is the number of years which have elapsed since the time of which ,i am speaking2 and in all the ages and changes of things there has never been any settlement of the earth flowing down from the mountains1 as in other places1 which is worth speaking of2 it has always been carried round in a circle1 and disappeared in the depths below4 ,the consequence is that1 in comparison with what then was1 there are remaining in small islets only the bones of the wasted body1 as they may be called1 all the richer and softer parts of the soil having fallen away1 and the mere skeleton of the country being left4444 ,and next1 if ,i have not forgotten what ,i heard when ,i was a child1 ,i will impart to you the character and origin of their adversaries2 for friends should not keep their stories to themselves1 but have them in common4 ,yet1 before proceeding further in the narrative1 ,i ought to warn you that you must not be surprised1 if you should hear ,hellenic names given to foreigners4 ,i will tell you the reason of this3 ,solon1 who was intending to use the tale for his poem1 made an investigation into the meaning of the names1 and found that the early ,egyptians1 in writing them down1 had translated them into their own language1 and he recovered the meaning of the several names and retranslated them1 and copied them out again in our language4 ,my great-grandfather1 ,dropidas1 had the original writing1 which is still in my possession1 and was carefully studied by me when ,i was a child4 ,therefore1 if you hear names such as are used in this country1 you must not be surprised1 for ,i have told you the reason of them4 ,the tale1 which was of great length1 began as follows3 ,i have before remarked1 in speaking of the allotments of the gods1 that they distributed the whole earth into portions differing in extent1 and made themselves temples and sacrifices4 ,and ,poseidon1 receiving for his lot the island of ,atlantis1 begat children by a mortal woman1 and settled them in a part of the island which ,i will proceed to describe4 ,on the side toward the sea1 and in the centre of the whole island1 there was a plain which is said to have been the fairest of all plains1 and very fertile4 ,near the plain1 and also in the centre of the island1 at a distance of about fifty stadia1 there was a mountain1 not very high on any side4 ,in this mountain there dwelt one of the earth-born primeval men of that country1 whose name was ,evenor1 and he had a wife named ,leucippe1 and they had an only daughter1 who was named ,cleito4 ,the maiden was growing up to womanhood when her father and mother died2 ,poseidon fell in love with her1 and had intercourse with her2 and1 breaking the ground1 enclosed the hill in which she lived all around1 making alternate zones of sea and land1 larger and smaller1 encircling one another2 there were two of land and three of water1 which he turned as with a lathe out of the centre of the island1 equidistant every way1 so that no man could get to the island1 for ships and voyagers were not yet heard of4 ,he himself1 as he was a god1 found no difficulty in making special arrangements for the centre island1 bringing two streams of water under the earth1 which he caused to ascend as springs1 one of warm water and the other of cold1 and making every variety of food to spring up abundantly in the earth4 ,he also begat and brought up five pairs of male children1 dividing the island of ,atlantis into ten portions2 he gave to the first-born of the eldest pair his mother's dwelling and the surrounding allotment1 which was the largest and best1 and made him king over the rest2 the others he made princes1 and gave them rule over many men and a large territory4 ,he named them all3 the eldest1 who was king1 he named ,atlas1 and from him the whole island and the ocean received the name of ,atlantic4 ,to his twin brother1 who was born after him1 and obtained as his lot the extremity of the island toward the ,pillars of ,heracles1 as far as the country which is still called the region of ,gades in that part of the world1 he gave the name which in the ,hellenic language is ,eumelus1 in the language of the country which is named after him1 ,gadeirus4 ,of the second pair of twins1 he called one ,ampheres and the other ,evmon4 ,to the third pair of twins he gave the name ,mneseus to the elder1 and ,autochthon to the one who followed him4 ,of the fourth pair of twins he called the elder ,elasippus and the younger ,mestor4 ,and of the fifth pair he gave to the elder the name of ,azaes1 and to the younger ,diaprepes4 ,all these and their descendants were the inhabitants and rulers of divers islands in the open sea2 and also1 as has been already said1 they held sway in the other direction over the country within the ,pillars as far as ,egypt and ,tyrrhenia4 ,now ,atlas had a numerous and honorable family1 and his eldest branch always retained the kingdom1 which the eldest son handed on to his eldest for many generations2 and they had such an amount of wealth as was never before possessed by kings and potentates1 and is not likely ever to be again1 and they were furnished with everything which they could desire both in city and country4 ,for1 because of the greatness of their empire1 many things were brought to them from foreign countries1 and the island itself provided much of what was required by them for the uses of life4 ,in the first place1 they dug out of the earth whatever was to be found there1 mineral as well as metal1 and that which is now only a name1 and was then something more than a name--orichalcum--was dug out of the earth in many parts of the island1 and1 with the exception of gold1 was esteemed the most precious of metals among the men of those days4 ,there was an abundance of wood for carpenters' work1 and sufficient maintenance for tame and wild animals4 ,moreover1 there were a great number of elephants in the island1 and there was provision for animals of every kind1 both for those who live in lakes and marshes and rivers1 and also for those which live in mountains1 and on plains1 and therefore for the animal which is the largest and most voracious of them4 ,also whatever fragrant things there are in the earth1 whether roots1 or herbage1 or woods1 or distilling drops of flowers1 or fruits1 grew and thrived in that land2 and again1 the cultivated fruit of the earth1 both the dry edible fruit and other species of food1 which we call by the general name of legumes1 and the fruits having a hard rind1 affording drinks1 and meats1 and ointments1 and good store of chestnuts and the like1 which may be used to play with1 and are fruits which spoil with keeping--and the pleasant kinds of dessert which console us after dinner1 when we are full and tired of eating--all these that sacred island lying beneath the sun brought forth fair and wondrous in infinite abundance4 ,all these things they received from the earth1 and they employed themselves in constructing their temples1 and palaces1 and harbors and docks2 and they arranged the whole country in the following manner3 first of all they bridged over the zones of sea which surrounded the ancient metropolis1 and made a passage into and out of the royal palace2 and then they began to build the palace in the habitation of the god and of their ancestors4 ,this they continued to ornament in successive generations1 every king surpassing the one who came before him to the utmost of his power1 until they made the building a marvel to behold for size and for beauty4 ,and1 beginning from the sea1 they dug a canal three hundred feet in width and one hundred feet in depth1 and fifty stadia in length1 which they carried through to the outermost zone1 making a passage from the sea up to this1 which became a harbor1 and leaving an opening sufficient to enable the largest vessels to find ingress4 ,moreover1 they divided the zones of land which parted the zones of sea1 constructing bridges of such a width as would leave a passage for a single trireme to pass out of one into another1 and roofed them over2 and there was a way underneath for the ships1 for the banks of the zones were raised considerably above the water4 ,now the largest of the zones into which a passage was cut from the sea was three stadia in breadth1 and the zone of land which came next of equal breadth2 but the next two1 as well a zone of water as of land1 were two stadia1 and the one which surrounded the central island was a stadium only in width4 ,the island in which the palace was situated had a diameter of five stadia4 ,this1 and the zones and the bridge1 which was the sixth part of a stadium in width1 they surrounded by a stone wall1 on either side placing towers1 and gates on the bridges where the sea passed in4 ,the stone which was used in the work they quarried from underneath the centre island and from underneath the zones1 on the outer as well as the inner side4 ,one kind of stone was white1 another black1 and a third red2 as they quarried1 they at the same time hollowed out decks1 double within1 having roofs formed out of the native rock4 ,some of their buildings were simple1 but in others they put together different stones1 which they intermingled for the sake of ornament1 to be a natural source of delight4 ,the entire circuit of the wall which went around the outermost one they covered with a coating of brass1 and the circuit of the next wall they coated with tin1 and the third1 which encompassed the citadel1 flashed with the red light of orichalcum4 ,the palace in the interior of the citadel was constructed in this wise3 in the centre was a holy temple1 dedicated to ,cleito and ,poseidon1 which remained inaccessible1 and was surrounded by an enclosure of gold2 this was the spot in which was originally begotten the race of ten princes1 and thither they annually brought the fruits of the earth in their season from all the ten portions1 and performed sacrifices to each of them4 ,here1 too1 was ,poseidon's own temple1 of a stadium in length and half a stadium in width1 and of a proportionate height1 having a sort of barbaric splendor4 ,all the outside of the temple1 with the exception of the pinnacles1 they covered with silver1 and the pinnacles with gold4 ,in the interior of the temple the roof was of ivory1 adorned everywhere with gold and silver and orichalcum2 all the other parts of the walls and pillars and floor they lined with orichalcum4 ,in the temple they placed statues of gold3 there was the god himself standing in a chariot--the charioteer of six winged horses--and of such a size that he touched the roof of the building with his head2 around him were a hundred ,nereids riding on dolphins1 for such was thought to be the number of them in that day4 ,there were also in the interior of the temple other images which had been dedicated by private individuals4 ,and around the temple1 on the outside1 were placed statues of gold of all the ten kings and of their wives2 and there were many other great offerings1 both of kings and of private individuals1 coming both from the city itself and the foreign cities over which they held sway4 ,there was an altar1 too1 which in size and workmanship corresponded to the rest of the work1 and there were palaces in like manner which answered to the greatness of the kingdom and the glory of the temple4 ,in the next place1 they used fountains both of gold and hot springs4 ,these were very abundant1 and both kinds wonderfully adapted to use by reason of the sweetness and excellence of their waters4 ,they constructed buildings about them1 and planted suitable trees2 also cisterns1 some open to the heaven1 others which they roofed over1 to be used in winter as warm baths3 there were the king's baths1 and the baths of private persons1 which were kept apart2 also separate baths for women1 and others again for horses and cattle1 and to them they gave as much adornment as was suitable for them4 ,the water which ran off they carried1 some to the grove of ,poseidon1 where were growing all manner of trees of wonderful height and beauty1 owing to the excellence of the soil2 the remainder was conveyed by aqueducts which passed over the bridges to the outer circles3 and there were many temples built and dedicated to many gods2 also gardens and places of exercise1 some for men1 and some set apart for horses1 in both of the two islands formed by the zones2 and in the centre of the larger of the two1 there was a racecourse of a stadium in width1 and in length allowed to extend all round the island1 for horses to race in4 ,also there were guard-houses at intervals for the body-guard1 the more trusted of whom had their duties appointed to them in the lesser zone1 which was nearer the ,acropolis2 while the most trusted of all had houses given them within the citadel1 and about the persons of the kings4 ,the docks were full of triremes and naval stores1 and all things were quite ready for use4 ,enough of the plan of the royal palace4 ,crossing the outer harbors1 which were three in number1 you would come to a wall which began at the sea and went all round2 this was everywhere distant fifty stadia from the largest zone and harbor1 and enclosed the whole1 meeting at the mouth of the channel toward the sea4 ,the entire area was densely crowded with habitations2 and the canal and the largest of the harbors were full of vessels1 and merchants coming from all parts1 who1 from their numbers1 kept up a multitudinous sound of human voices and din of all sorts1 night and day4 ,i have repeated his descriptions of the city and the parts about the ancient palace nearly as he gave them1 and now ,i must endeavor to describe the nature and arrangement of the rest of the country4 ,the whole country was described as being very lofty and precipitous on the side of the sea1 but the country immediately about and surrounding the city was a level plain1 itself surrounded by mountains which descended toward the sea2 it was smooth and even1 but of an oblong shape1 extending in one direction three thousand stadia1 and going up the country from the sea through the centre of the island two thousand stadia2 the whole region of the island lies toward the south1 and is sheltered from the north4 ,the surrounding mountains were celebrated for their number and size and beauty1 in which they exceeded all that are now to be seen anywhere2 having in them also many wealthy inhabited villages1 and rivers and lakes1 and meadows supplying food enough for every animal1 wild or tame1 and wood of various sorts1 abundant for every kind of work4 ,i will now describe the plain1 which had been cultivated during many ages by many generations of kings4 ,it was rectangular1 and for the most part straight and oblong2 and what it wanted of the straight line followed the line of the circular ditch4 ,the depth and width and length of this ditch were incredible1 and gave the impression that such a work1 in addition to so many other works1 could hardly have been wrought by the hand of man4 ,but ,i must say what ,i have heard4 ,it was excavated to the depth of a hundred feet1 and its breadth was a stadium everywhere2 it was carried round the whole of the plain1 and was ten thousand stadia in length4 ,it received the streams which came down the mountains1 and winding round the plain1 and touching the city at various points1 was there let off into the sea4 ,from above1 likewise1 straight canals of a hundred feet in width were cut in the plain1 and again let off into the ditch1 toward the sea4 ,these canals were at intervals of a hundred stadia1 and by them they brought down the wood from the mountains to the city1 and conveyed the fruits of the earth in ships1 cutting transverse passages from one canal into another1 and to the city4 ,twice in the year they gathered the fruits of the earth--in winter having the benefit of the rains1 and in summer introducing the water of the canals4 ,as to the population1 each of the lots in the plain had an appointed chief of men who were fit for military service1 and the size of the lot was to be a square of ten stadia each way1 and the total number of all the lots was sixty thousand4 ,and of the inhabitants1 of the mountains and of the rest of the country there was also a vast multitude having leaders1 to whom they were assigned according to their dwellings and villages4 ,the leader was required to furnish for the wars the sixth portion of a war-chariot1 so as to make up a total of ten thousand chariots2 also two horses and riders upon them1 and a light chariot without a seat1 accompanied by a fighting man on foot carrying a small shield1 and having a charioteer mounted to guide the horses2 also1 he was bound to furnish two heavy-armed men1 two archers1 two slingers1 three stone-shooters1 and three javelin men1 who were skirmishers1 and four sailors1 to make up a complement of twelve hundred ships4 ,such was the order of war in the royal city4 ,that of the other nine governments was different in each of them1 and would be wearisome to narrate4 ,as to offices and honors the following was the arrangement from the first3 each of the ten kings1 in his own division and in his own city1 had the absolute control of the citizens1 and in many cases1 of the laws1 punishing and slaying whomsoever he would4 ,now the relations of their governments to one another were regulated by the injunctions of ,poseidon as the law had handed them down4 ,these were inscribed by the first men on a column of orichalcum1 which was situated in the middle of the island1 at the temple of ,poseidon1 whither the people were gathered together every fifth and sixth years alternately1 thus giving equal honor to the odd and to the even number4 ,and when they were gathered together they consulted about public affairs1 and inquired if any one had transgressed in anything1 and passed judgment on him accordingly--and before they passed judgment they gave their pledges to one another in this wise3 ,there were bulls who had the range of the temple of ,poseidon2 and the ten who were left alone in the temple1 after they had offered prayers to the gods that they might take the sacrifices which were acceptable to them1 hunted the bulls without weapons1 but with staves and nooses2 and the bull which they caught they led up to the column4 ,the victim was then struck on the head by them1 and slain over the sacred inscription4 ,now on the column1 besides the law1 there was inscribed an oath invoking mighty curses on the disobedient4 ,when1 therefore1 after offering sacrifices according to their customs1 they had burnt the limbs of the bull1 they mingled a cup and cast in a clot of blood for each of them4 ,the rest of the victim they took to the fire1 after having made a purification of the column all round4 ,they then drew from the cup in golden vessels1 and1 pouring a libation on the fire1 they swore that they would judge according to the laws on the column1 and would punish any one who had previously transgressed1 and that for the future they would not1 if they could help1 transgress any of the inscriptions1 and would not command1 or obey any ruler who commanded them1 to act otherwise than according to the laws of their father ,poseidon4 ,this was the prayer which each of them offered up for himself and for his family1 at the same time drinking1 and dedicating the vessel in the temple of the god2 and1 after spending some necessary time at supper1 when darkness came on and the fire about the sacrifice was cool1 all of them put on most beautiful azure robes1 and1 sitting on the ground at night near the embers of the sacrifices on which they had sworn1 and extinguishing all the fires about the temple1 they received and gave judgment1 if any of them had any accusation to bring against any one2 and1 when they had given judgment1 at daybreak they wrote down their sentences on a golden tablet1 and deposited them as memorials with their robes4 ,there were many special laws which the several kings had inscribed about the temple1 but the most important was the following3 that they were not to take up arms against one another1 and they were all to come to the rescue1 if any one in any city attempted to overthrow the royal house4 ,like their ancestors1 they were to deliberate in common about war and other matters1 giving the supremacy to the family of ,atlas2 and the king was not to have the power of life or death over any of his kinsmen1 unless he had the assent of the majority of the ten kings4 ,such was the vast power which the god settled in the lost island of ,atlantis2 and this he afterward directed against our land on the following pretext1 as traditions tell4 ,for many generations1 as long as the divine nature lasted in them1 they were obedient to the laws1 and well-affectioned toward the gods1 who were their kinsmen1 for they possessed true and in every way great spirits1 practicing gentleness and wisdom in the various chances of life1 and in their intercourse with one another4 ,they despised everything but virtue1 not caring for their present state of life1 and thinking lightly on the possession of gold1 and other property1 which seemed only a burden to them2 neither were they intoxicated by luxury1 nor did wealth deprive them of their self-control2 but they were sober1 and saw clearly that all these goods are increased by virtuous friendship with one another1 and that by excessive zeal for them and honor of them1 the good of them is lost1 and friendship perishes with them4 ,by such reflections1 and by the continuance in them of a divine nature1 all that which we have described waxed and increased in them2 but when this divine portion began to fade away in them1 and became diluted too often1 and with too much of the mortal admixture1 and the human nature got the upper hand1 then1 they being unable to bear their fortune1 became unseemly1 and to him who had an eye to see1 they began to appear base1 and had lost the fairest of their precious gifts2 but to those who had no eye to see the true happiness they still appeared glorious and blessed at the very time when they were filled with unrighteous avarice and power4 ,zeus1 the god of gods1 who rules with law1 and is able to see into such things1 perceiving that an honorable race was in a most wretched state1 and wanting to inflict punishment on them1 that they might be chastened and improved1 collected all the gods into his most holy habitation1 which1 being placed in the centre of the world1 sees all things that partake of generations4 ,and when he had called them together1 he spake as follows3 ,the story abruptly ends here1 for ,plato left no further record4 ,,chapter ,,xxxix ,,nature',s ,,warning ,,of ,,coming ,,earthquakes ,that there are signs of coming earthquakes which might be read by man1 had he sufficient knowledge1 there would seem to be but little doubt4 ,these phenomena follow natural laws so that the approach of an earthquake must necessarily be in a definite order both as regards the phenomena which precede as well as those which follow it4 ,there should1 therefore1 be signs that would enable one to predict its coming1 although it must be acknowledged that these signs1 so far as we actually know1 are indistinct4 ,it may seem to the unthinking and unobservant that the awful catastrophe of an earthquake comes entirely unheralded2 that1 apparently1 it is not until the earth's surface begins to rock to and fro under the mighty forces that are causing destruction that its presence can be known4 ,there are1 however1 many reasons for believing that in1 perhaps1 the greatest number of cases1 it might have been foreseen1 if greater attention had been given to the slight indications of its probable approach a short time before its occurrence4 ,it is evident that the conditions of great pressure or stress in the earth's crust which finally result in a disastrous earthquake have been slowly accumulating for a long time1 and that when the pressure at last reaches a point where the crust has to yield or slip1 the ground is suddenly crushed and tossed to and fro while vast fissures and chasms are produced in the subterranean regions4 ,at those points of the earth immediately above or in the neighborhood of such regions it is possible that there are many signs of the coming quake2 and1 although indistinguishable by our duller senses1 are readily appreciated by the more highly developed senses of the lower animals4 ,indeed1 had we accustomed ourselves to reading the various indications of nature as the lower animals have1 we1 too1 might be able to read these warnings of the coming earthquake4 ,at great distances from the place where the earthquake starts there would necessarily be a better opportunity for predicting its approach4 ,as already stated1 what is called an earthquake does not consist of a single shaking of the ground1 but of a highly complex series of shakings4 ,according to ,mallet1 the following waves start at the same time from the place of origin of an earthquake1 when located on the bed of an ocean2 i4 e41 an earth sound wave and a earth wave constituting the earth's shake2 a sound wave through the ocean1 another through the air2 a sea wave called by him a forced sea wave1 and finally the great sea wave4 ,these waves reach a distant point in the following order3 the sound wave through the earth and the great earthquake or shake which produces the damage4 ,then a smaller sea wave called the forced sea wave4 ,this is followed almost immediately by the sound wave through the sea4 ,next come the air sound wave and finally the great sea wave2 which1 rushing in on the shore1 sweeps nearly everything before it4 ,in other words1 the disturbances produced by the great earthquake follow in this order of sequence4 ,if1 therefore1 the great earthquake wave proper transmitted through the earth should for any reason be delayed in reaching a distant place1 the great sound waves should be able to give warning of the coming disturbances4 ,again1 as we have already seen1 the earthquake wave is preceded by a number of preliminary tremors1 and is followed by a number of after tremors or earthquake echoes4 ,since1 therefore1 the preliminary waves reach a place first1 it would seem that the approach of an earthquake must be heralded by the preliminary tremors4 ,these1 perhaps1 at least in part1 enable the lower animals to detect its coming4 ,again1 in almost all instances there are a number of preliminary shocks that precede the great earthquake shock4 ,some of these preliminary shocks continue at intervals for several days or even longer4 ,sometimes1 indeed1 these subterranean sounds fail to be followed by earthquakes4 ,milne thinks that these sounds are caused by the preliminary tremors which precede the principal shock of the earthquake and that they reach the place first4 ,here again then it is evident that1 were we able to interpret properly these sounds1 we would probably be able to foretell the coming quake with a fair degree of certainty4 ,there would appear to be no reasonable doubt that in some manner which we have not yet been able to discover1 but probably along some of the lines indicated above1 animals are capable of recognizing a coming earthquake4 ,long before the coming of the catastrophe they are said to exhibit extreme terror1 and in many cases appear to seek the companionship of man1 as if for protection4 ,that the senses of smell and hearing are far more acute in the lower animals than in man no one can reasonably doubt4 ,the manner in which a trained dog can follow a scent1 for a long time after the animal or thing producing it has passed1 far exceeds the power of scent possessed by man1 and it is more than likely that this same power is possessed by all animals who live upon or prey upon other animals4 ,it is probable that faintly odorous vapors or gases escape from the crust shortly before the great shock occurs1 and that these faint odors are warnings to the animals of the approaching calamity4 ,the sense of hearing also is much more acute in the lower animals4 ,daubeny is evidently of this belief1 as will be seen from the following3 ,these gases and vapors 7alluding to emanations given off from the ground during earthquakes7 exert an influence on the barometer1 which does appear to be indirectly affected by the earthquake4 ,then1 similar properties also may occasion that uneasiness which animals are said to evince before any such event4 ,thus1 according to the accounts of some writers1 rats and mice leave their holes1 alligators seek the dry land1 quadrupeds snuff the ground1 and manifest such signs of the impending calamity that in countries where earthquakes are common1 the inhabitants take the alarm in consequence1 and escape from their houses4 ,it is right1 however1 to add1 that more recent authorities dispute altogether the correctness of these statements4 ,dutton doubts the ability of animals to foretell coming earthquake shocks4 ,but that the lower animals do exhibit signs of fear at the approach of an earthquake has been repeatedly asserted by good observers4 ,hamilton1 who made a careful examination of the neighboring country during the great earthquake at ,calabria1 asserts that horses and oxen during the shocks extended their legs widely in order to avoid being thrown down1 and that hogs1 oxen1 horses1 and mules1 and also geese1 appeared to be painfully aware of the approach of the earthquake of ,calabria2 and the neighing of a horse1 the braying of an ass1 or the cackling of a goose1 even when he 7,hamilton7 was making his survey 7after the occurrence of the great earthquake shock71 drove the people out of their temporary sheds in expectation of a shock4 ,it is asserted that birds appear to be especially sensible to a coming earthquake shock4 ,that geese will quit the water in which they were swimming before the earthquake and will not return to it4 ,it is quite possible that these birds with their heads immersed in the water can hear the distant murmurings long before they become audible in the air4 ,von ,hoff makes the following statement3 ,it has been remarked that at such times 7immediately before the coming of an earthquake shock71 domestic animals showed a decided uneasiness1 dogs howled mournfully1 horses neighed in an unusual manner1 and poultry flew restlessly about4 ,these latter phenomena might easily be produced by mephitic vapours1 which often ascend to the surface of the earth before the breaking out of an earthquake4 ,mallet states that there is abundant evidence that earthquake shocks1 even when not of very great intensity1 produce nausea in both men and women4 ,this would seem natural1 since1 as everyone knows1 until one is accustomed to sea-voyages1 merely to be tossed to and fro by the motion of the waves results in the production of sea-sickness4 ,it has been also noticed that during earthquakes fish which under ordinary circumstances live in the mud at the bottom of bodies of water come near to the surface and at such times can be caught in great numbers4 ,mallet cites the following effects produced by earthquakes3 ,amongst the effects supposed to be produced by the earthquake on the atmosphere were reckoned tempestuous winds1 thunder-storms1 meteors1 coldness of the air1 severe winters1 heavy rains1 miasmata1 producing diseases and affecting vegetation4 ,a very remarkable instance of the latter is quoted1 namely1 that in ,peru1 after the earthquake of #afhg1 wheat and barley would not thrive at all1 though formerly the country was remarkably favourable for them4 ,sir ,charles ,lyell notes the following phenomena attending earthquakes3 ,irregularities in the seasons preceding or following the shocks2 sudden gusts of wind1 interrupted by dead calms2 violent rains at unusual seasons1 or in countries where1 as a rule1 they are almost unknown2 a reddening of the sun's disk1 and haziness in the air1 often continued for months2 an evolution of electric matter1 or of inflammable gas from the soil1 with sulphurous and mephitic vapours2 noises underground1 like the running of carriages1 or the discharge of artillery1 or distant thunder2 animals uttering cries of distress1 and evincing extraordinary alarm1 being more sensitive than men to the slightest movement2 a sensation like sea-sickness1 and a dizziness in the head1 experienced by men4 ,these1 and other phenomena1 less connected with our present subject as geologists1 have recurred again and again at distant ages1 and in all parts of the globe4 ,,the ,,end ,,footnotes3 ,footnote #a3 ,a point on the other side of the earth directly opposite a given point4 ,footnote #b3 ,a fracture of a stratum1 or a general rock mass1 with a relative displacement of the opposite sides of the break4 ,the plane or fracture of a fault1 known as the fault-plane1 is seldom vertical4 ,the higher side is called the heaved or upthrow side2 the opposite side the thrown or downthrow side4 ,footnote #c3 ,tectonic ,earthquake4 ,an earthquake due to the sudden slip of faulted strata4 ,footnote #d3 ,i4 e41 burnt out mountain1 extinct volcano4 ,footnote #e3 ,epicentre4 ,a point on the surface of the earth vertically above the point of origin of an earthquake1 or the place where it starts4 ,transcriber's ,notes ,obvious printer errors have been silently corrected4 ,some illustrations have been moved to paragraph breaks4 ,page #dc3 ,kamehamoha could be a typo for ,kamehameha4 ,page #fh3 ,changed salter to saltier4 7,orig3 another with water salter than the sea17 ,page #gf3 ,changed ,ena to ,etna4 7,orig3 during his time ,mt4 ,ena had lost so much of its height7 ,page #aae3 eruption during the winter of #ahda-dc1 could be a typo for #ahda-db or #ahdb-dc4 ,page #abb3 ,mont ,pele could be a typo for ,mount ,pele4 ,page #acf3 #dc ,c4 7#aji #d' ,f474 could be a typo for 7#aji4d ,f474 ,page #cda3 ,changed one-eight to one-eighth4 7,orig3 ,it was equal to one-eight of a ,roman mile7 ,retained the following spelling variations3 ,page #di3 ,the largest volcano in ,iceland1 the ,dyngjufkll1 ,page #eg3 ,the largest volcano in ,iceland is ,dyngjufjoll4 ,pages #eb1 #aic1 #caa3 ,geikie ,page #aha3 ,geicke ,pages #ag1 #aef1 #beg3 ,hindostan ,page #afe3 ,hindustan ,page #fc3 ,lucullis ,page #gf3 ,lucullus