,young ,folks' ,library ,selections from the ,choicest ,literature of ,all ,lands2 ,folk-,lore1 ,fairy ,tales1 ,fables1 ,legends1 ,natural ,history1 ,wonders of ,earth1 ,sea and ,sky1 ,animal ,stories1 ,sea ,tales1 ,brave ,deeds1 ,explorations1 ,stories of ,school and ,college ,life1 ,biography1 ,history1 ,patriotic ,eloquence1 ,poetry ,third ,edition ,revised in ,conference by ,thomas ,bailey ,aldrich1 ,editor-in-,chief1 ,president ,william ,jewett ,tucker1 ,hamilton ,wright ,mabie1 ,henry ,van ,dyke1 ,nathan ,haskell ,dole ,twenty ,volumes ,richly ,illustrated ,boston ,hall and ,locke ,company ,publishers ,stanhope ,press ,f4,h4 ,gilson ,company ,boston1 ,u4,s4,a4 #aijb ,,editorial ,,board ,,thomas ,,bailey ,,aldrich1 ,editor-in-chief1 ,author1 poet1 former editor ,atlantic ,monthly1 ,boston1 ,mass4 ,the ,,hon4 ,,john ,d4 ,,long1 ,secretary of the ,united ,states ,navy1 ,boston4 ,,hamilton ,,wright ,,mabie1 ,,ll4,d41 ,author1 literarian1 associate editor ,the ,outlook1 ,new ,york4 ,,ernest ,,thompson ,,seton1 ,artist1 author1 ,new ,york4 ,,john ,,townsend ,,trowbridge1 ,author1 poet1 and editor1 ,arlington1 ,mass4 ,the ,,reverend ,,cyrus ,,townsend ,,brady1 ,archdeacon1 author1 ,philadelphia4 ,,joel ,,chandler ,,harris1 ,humorous writer1 ,atlanta1 ,ga4 ,,mary ,,hartwell ,,catherwood1 ,historical novelist1 ,chicago4 ,,laura ,e4 ,,richards1 ,author1 ,gardiner1 ,me4 ,,roswell ,,field1 ,author1 editor ,the ,evening ,post1 ,chicago4 ,,tudor ,,jenks1 ,author1 associate editor ,saint ,nicholas1 ,new ,york4 ,,george ,a4 ,,henty1 ,traveller1 author1 ,london1 ,england4 ,,kirk ,,munroe1 ,writer of stories for boys1 ,cocoanut ,grove1 ,fla4 ,,edith ,m4 ,,thomas1 ,poet1 ,west ,new ,brighton1 ,n4,y4 ,,caroline ,,ticknor1 ,author1 editor1 ,boston4 ,,nathan ,,haskell ,,dole1 ,author1 translator1 literary editor ,current ,history1 ,boston4 ,,william ,,rainey ,,harper1 ,d4,d41 ,,ll4,d41 ,president ,chicago ,university4 ,,david ,,starr ,,jordan1 ,m4,d41 ,,ll4,d41 ,president ,leland ,stanford ,junior ,university1 naturalist1 writer1 ,stanford ,university1 ,cal4 ,,charles ,,eliot ,,norton1 ,a4,m41 ,,ll4,d41 etc41 ,scholar1 author1 ,emeritus ,professor of ,art at ,harvard ,university4 ,,henry ,,van ,,dyke1 ,d4,d41 ,,ll4,d41 ,clergyman1 author1 ,professor ,princeton ,university4 ,the ,,reverend ,,thomas ,j4 ,,shahan1 ,dean of the ,faculty of ,divinity1 ,professor of ,early ,ecclesiastical ,history1 ,catholic ,university1 ,washington1 ,d4,c4 ,,william ,p4 ,,trent1 ,author1 editor1 ,professor of ,english ,literature1 ,columbia ,university1 ,new ,york ,city4 ,,edward ,,singleton ,,holden1 ,a4,m41 ,,ll4,d41 ,ex-president ,university of ,california1 astronomer1 author1 ,u4,s4 ,military ,academy1 ,west ,point4 ,,edwin ,,erle ,,sparks1 ,professor of ,american ,history1 ,chicago ,university4 ,the ,,very ,,rev4 ,,george ,m4 ,,grant1 ,d4,d41 ,,ll4,d41 ,educator1 author1 vice-principal ,queen's ,college1 ,kingston1 ,ont4 ,,baroness ,,von ,,bulow1 ,educator1 author1 ,dresden1 ,germany4 ,,abbie ,,farwell ,,brown1 ,author1 ,boston4 ,,charles ,,welsh1 ,managing ,editor1 ,author1 lecturer1 editor1 ,winthrop ,highlands1 ,mass4 ,,list ,,of ,,volumes ,,volume ,i4 ,,the ,,story ,,teller ,edited by ,,charles ,,eliot ,,norton ,,volume ,,ii4 ,,the ,,merry ,,maker ,edited by ,,joel ,,chandler ,,harris ,,volume ,,iii4 ,,famous ,,fairy ,,tales ,edited by ,,roswell ,,field ,,volume ,,iv4 ,,tales ,,of ,,fantasy ,edited by ,,tudor ,,jenks ,,volume ,v4 ,,myths ,,and ,,legends ,edited by ,,thomas ,j4 ,,shahan ,,volume ,,vi4 ,,the ,,animal ,,story ,,book ,edited by ,,ernest ,,thompson ,,seton ,,volume ,,vii4 ,,school ,,and ,,college ,,days ,edited by ,,kirk ,,munroe and ,,mary ,,hartwell ,,catherwood ,,volume ,,viii4 ,,book ,,of ,,adventure ,edited by ,,nathan ,,haskell ,,dole ,,volume ,,ix4 ,,famous ,,explorers ,edited by ,,edwin ,,erle ,,sparks ,,volume ,x4 ,,brave ,,deeds ,edited by ,,john ,,townsend ,,trowbridge ,,volume ,,xi4 ,,wonders ,,of ,,earth1 ,,sea ,,and ,,sky ,edited by ,,edward ,,singleton ,,holden ,,volume ,,xii4 ,,famous ,,travels ,edited by ,,george ,a4 ,,henty ,,volume ,,xiii4 ,,sea ,,stories ,edited by ,,cyrus ,,townsend ,,brady ,,volume ,,xiv4 ,a ,,book ,,of ,,natural ,,history ,edited by ,,david ,,starr ,,jordan ,,volume ,,xv4 ,,historic ,,scenes ,,in ,,fiction ,edited by ,,henry ,,van ,,dyke ,,volume ,,xvi4 ,,famous ,,battles ,,by ,,land ,,and ,,sea ,edited by ,,john ,d4 ,,long ,,volume ,,xvii4 ,,men ,,who ,,have ,,risen ,edited by ,,hamilton ,,wright ,,mabie4 ,,volume ,,xviii4 ,,book ,,of ,,patriotism ,edited by ,,volume ,,xix4 ,,leaders ,,of ,,men1 ,,or ,,history ,,told ,,in ,,biography ,edited by ,,william ,,rainey ,,harper ,,volume ,,xx4 ,,famous ,,poems ,selected by ,,thomas ,,bailey ,,aldrich1 with ,poetical ,foreword by ,,edith ,m4 ,,thomas4 ,illustration3 ,a ,,geyser ,volume ,,xi3 ,,wonders ,,of ,,earth1 ,,sea ,,and ,,sky ,edited by ,,edward ,,singleton ,,holden ,boston ,hall and ,locke ,company ,publishers #aijb ,,contents ,,list ,,of ,,illustrations xi ,,the ,,marvels ,,of ,,nature xiii ,,by ,,professor ,e4,s4 ,,holden4 ,,what ,,the ,,earth',s ,,crust ,,is ,,made ,,of #a ,,by ,,agnes ,,giberne4 ,,america ,,the ,,old ,,world #de ,,by ,,louis ,,agassiz4 ,,some ,,records ,,of ,,the ,,rocks #gg ,,by ,n4,s4 ,,shaler4 ,,the ,,pitch ,,lake ,,in ,,the ,,west ,,indies #ig ,,by ,,charles ,,kingsley4 ,a ,,stalagmite ,,cave #aaa ,,by ,,sir ,c4 ,,wyville ,,thomson4 ,,the ,,big ,,trees ,,of ,,california #aai ,,by ,,alfred ,,russel ,,wallace4 ,,what ,,is ,,evolution8 #abg ,,by ,,professor ,,edward ,s4 ,,holden4 ,,how ,,the ,,soil ,,is ,,made #ace ,,by ,,charles ,,darwin4 ,,zo,,logical ,,myths #adc ,,by ,,andrew ,,wilson4 ,,on ,a ,,piece ,,of ,,chalk #aga ,,by ,t4,h4 ,,huxley4 ,a ,,bit ,,of ,,sponge #bje ,,by ,a4 ,,wilson4 ,,the ,,greatest ,,sea-,,wave ,,ever ,,known #baa ,,by ,r4,a4 ,,proctor4 ,,the ,,phosphorescent ,,sea #bbh ,,by ,w4,s4 ,,dallas4 ,,comets #bea ,,by ,,camille ,,flammarion4 ,,the ,,total ,,solar ,,eclipse ,,of #ahhc #bfa ,,by ,e4,s4 ,,holden4 ,,halos--,,parhelia--,,the ,,spectre ,,of ,,the ,,brocken1 ,,etc4 #bfh ,,by ,,camille ,,flammarion4 ,,the ,,planet ,,venus #bhb ,,by ,,agnes ,m4 ,,clerke4 ,,the ,,stars #bif ,,by ,,sir ,r4,s4 ,,ball4 ,,rain ,,and ,,snow #cdb ,,by ,,john ,,tyndall4 ,,the ,,organic ,,world #ceg ,,by ,,st4 ,,george ,,mivart4 ,,inhabitants ,,of ,,my ,,pool #cff ,,by ,,arabella ,b4 ,,buckley4 ,,biographical ,,notes4 #chg ,,suggestions ,,for ,,supplementary ,,reading4 #chi ,,note4 ,the publishers' acknowledgments are due to ,messrs4 ,houghton1 ,mifflin ,co41 for permission to use ,america and the ,old ,world1 by ,l4 ,agassiz2 to ,messrs4 ,d4,c4 ,heath ,co4 for permission to use ,some ,records of the ,rocks1 by ,professor ,n4,s4 ,shaler2 and to ,professor ,e4,s4 ,holden for permission to use ,what is ,evolution8 and ,an ,astronomer's ,voyage to ,fairy ,land4 ,,list ,,of ,,colored ,,illustrations ,a ,,geyser4 ,frontispiece1 ,see ,page #dg ,,view ,,in ,a ,,ca,,on ,face ,page #ab ,a ,,volcano #dh ,a ,,stalagmite ,,cave #aaf ,,where ,,sponges ,,grow #bjh ,a ,,comet #bed ,,the ,,spectre ,,of ,,the ,,brocken #bgb ,,and ,,one ,,hundred ,,and ,,sixty-,,four ,,black ,,and ,,white ,,illustrations ,,in ,,the ,,text4 ,,the ,,marvels ,,of ,,nature ,,by ,,edward ,s4 ,,holden1 ,m4,a41 ,sc4,d4 ,,ll4,d4 ,the ,earth1 the ,sea1 the ,sky1 and their wonders--these are the themes of this volume4 ,the volume is so small1 and the theme so vast6 ,men have lived on the earth for hundreds of thousands of years2 and its wonders have increased1 not diminished1 with their experience4 ,to our barbarous ancestors of centuries ago1 all was mystery--the thunder1 the rainbow1 the growing corn1 the ocean1 the stars4 ,gradually and by slow steps they learned to house themselves in trees1 in caves1 in huts1 in houses2 to find a sure supply of food2 to provide a stock of serviceable clothing4 ,the arts of life were born2 tools were invented2 the priceless boon of fire was received2 tribes and clans united for defence2 some measure of security and comfort was attained4 ,with security and comfort came leisure2 and the mind of early ,man began curiously to inquire the meaning of the mysteries with which he was surrounded4 ,that curious inquiry was the birth of ,science4 ,art was born when some far-away ancestor1 in an idle hour1 scratched on a bone the drawing of two of his reindeer fighting1 or carved on the walls of his cave the image of the mammoth that he had but lately slain with his spear and arrows4 ,in a mind that is completely ignorant there is no wonder4 ,wonder is the child of knowledge--of partial and imperfect knowledge1 to be sure1 but still1 of knowledge4 ,the very first step in ,science is to make an inventory of external ,nature 7and by and by of the faculties of the mind that thinks74 ,the second step is to catalogue similar appearances together4 ,it is a much higher flight to seek the causes of likenesses thus discovered4 ,a few of the chapters of this volume are items in a mere catalogue of wonders1 and deserve their place by accurate and eloquent description4 ,most of them1 however1 represent higher stages of insight4 ,in the latter1 ,nature is viewed not only with the eye of the observer1 but also with the mind's eye1 curious to discover the reasons for things seen4 ,the most penetrating inward inquiry accompanies the acutest external observation in such chapters as those of ,darwin and ,huxley1 here reprinted4 ,now1 the point not to be overlooked is this3 to ,darwin and ,huxley1 as to their remote and uncultured ancestors1 the ,world--the ,earth1 the ,sea1 the ,sky--is full of wonders and of mysteries1 but the wonders are of a higher order4 ,the problems of the thunder and of the rainbow as they presented themselves to the men of a thousand generations ago1 have been fully solved3 but the questions2 what is the veritable nature of electricity1 exactly how does it differ from light1 are still unanswered4 ,and what are simple problems like these to the questions3 what is love2 why do we feel a sympathy with this person1 an antipathy for that2 and others of the sort8 ,science has made almost infinite advances since pre-historic man first felt the feeble current of intellectual curiosity amid his awe of the storm2 it has still to grow almost infinitely before anything like a complete explanation even of external ,nature is achieved4 ,suppose that1 at some future day1 all physical and mechanical laws should be found to be direct consequences of a single majestic law1 just as all the motions of the planets are 7but--are they87 the direct results of the single law of gravitation4 ,gravitation will1 probably1 soon be explained in terms of some remoter cause1 but the reason of that single and ultimate law of the universe which we have imagined would still remain unknown4 ,human knowledge will always have limits1 and beyond those limits there will always be room for mystery and wonder4 ,a complete and exhaustive explanation of the world is inconceivable1 so long as human powers and capacities remain at all as they now are4 ,it is important to emphasize such truths1 especially in a book addressed to the young4 ,when a lad hears for the first time that an astronomer1 by a simple pointing of his spectroscope1 can determine with what velocity a star is approaching the earth1 or receding from it1 or when he hears that the very shape of the revolving masses of certain stars can be calculated from simple measures of the sort1 he is apt to conclude that ,science1 which has made such astounding advances since the days of ,galileo and ,newton1 must eventually reach a complete explanation of the entire universe4 ,the conclusion is not unnatural1 but it is not correct4 ,there are limits beyond which ,science1 in this sense1 cannot go4 ,its scope is limited4 ,beyond its limits there are problems that it cannot solve1 mysteries that it cannot explain4 ,at the present moment1 for example1 the nature of ,force is unknown4 ,a weight released from the hand drops to the earth4 ,exactly what is the nature of the force with which the earth attracts it8 ,we do not know1 but it so happens that it is more than likely that an explanation will be reached in our own day4 ,gravity will be explained in terms of some more general forces4 ,the mystery will be pushed back another step1 and yet another and another4 ,but the progress is not indefinite4 ,if all the mechanical actions of the entire universe were to be formulated as the results of a single law or cause1 the cause of that cause would be still to seek1 as has been said4 ,we have every right to exult in the amazing achievements of ,science2 but we have not understood them until we realize that the universe of ,science has strict limits1 within which all its conquests must necessarily be confined4 ,humility1 and not pride1 is the final lesson of scientific work and study4 99 99 99 99 99 ,the choice of the selections printed in this volume has been necessarily limited by many hampering conditions1 that of mere space being one of the most harassing4 ,each of the chapters might readily be expanded into a volume4 ,volumes might be added on topics almost untouched here4 ,it has been necessary to pass over almost without notice matters of surpassing interest and importance3 ,electricity and its wonderful and new applications2 the new ,biology1 with its views upon such fundamental questions as the origins of life and death2 modern ,astronomy1 with its far-reaching pronouncements upon the fate of universes4 ,all these can only be touched lightly1 if at all4 ,it is the chief purpose of this volume to point the way towards the most modern and the greatest conclusions of ,science1 and to lay foundations upon which the reading of a life-time can be laid4 ,illustration3 ,signature3 ,edward ,s4 ,holden ,,united ,,states ,,military ,,academy1 ,,west ,,point1 ,january #a1 #aijb4 ,,wonders ,,of ,,earth1 ,,sea1 ,,and ,,sky ,,what ,,the ,,earth',s ,,crust ,,is ,,made ,,of 7,,from ,,the ,,world',s ,,foundations47 ,,by ,,agnes ,,giberne4 ,stand still and consider the wondrous works of ,god4 ,illustration ,what is the earth made of--this round earth upon which we human beings live and move8 ,a question more easily asked than answered1 as regards a very large portion of it4 ,for the earth is a huge ball nearly eight thousand miles in diameter1 and we who dwell on the outside have no means of getting down more than a very little way below the surface4 ,so it is quite impossible for us to speak positively as to the inside of the earth1 and what it is made of4 ,some people believe the earth's inside to be hard and solid1 while others believe it to be one enormous lake or furnace of fiery melted rock4 ,but nobody really knows4 ,this outside crust has been reckoned to be of many different thicknesses4 ,one man will say it is ten miles thick1 and another will rate it at four hundred miles4 ,so far as regards man's knowledge of it1 gained from mining1 from boring1 from examination of rocks1 and from reasoning out all that may be learned from these observations1 we shall allow an ample margin if we count the field of geology to extend some twenty miles downwards from the highest mountain-tops4 ,beyond this we find ourselves in a land of darkness and conjecture4 ,twenty miles is only one four-hundredth part of the earth's diameter--a mere thin shell over a massive globe4 ,if the earth were brought down in size to an ordinary large school globe1 a piece of rough brown paper covering it might well represent the thickness of this earth-crust1 with which the science of geology has to do4 ,and the whole of the globe1 this earth of ours1 is but one tiny planet in the great ,solar ,system4 ,and the centre of that ,solar ,system1 the blazing sun1 though equal in size to more than a million earths1 is yet himself but one star amid millions of twinkling stars1 scattered broadcast through the universe4 ,so it would seem at first sight that the field of geology is a small field compared with that of astronomy4444 ,with regard to the great bulk of the globe little can be said4 ,very probably it is formed through and through of the same materials as the crust4 ,this we do not know4 ,neither can we tell1 even if it be so formed1 whether the said materials are solid and cold like the outside crust1 or whether they are liquid with heat4 ,the belief has been long and widely held that the whole inside of the earth is one vast lake or furnace of melted fiery-hot material1 with only a thin cooled crust covering it4 ,some in the present day are inclined to question this1 and hold rather that the earth is solid and cold throughout1 though with large lakes of liquid fire here and there1 under or in her crust1 from which our volcanoes are fed4444 ,the materials of which the crust is made are many and various2 yet1 generally speaking1 they may all be classed under one simple word1 and that word is--,rock4 ,it must be understood that1 when we talk of rock in this geological sense1 we do not only mean hard and solid stone1 as in common conversation4 ,rock may be changed by heat into a liquid or molten state1 as ice is changed by heat to water4 ,liquid rock may be changed by yet greater heat to vapor1 as water is changed to steam1 only we have in a common way no such heat at command as would be needed to effect this4 ,rock may be hard or soft4 ,rock maybe chalky1 clayey1 or sandy4 ,rock may be so close-grained that strong force is needed to break it2 or it may be so porous--so full of tiny holes--that water will drain through it2 or it may be crushed and crumbled into loose grains1 among which you can pass your fingers4 ,the cliffs above our beaches are rock2 the sand upon our seashore is rock2 the clay used in brick-making is rock2 the limestone of the quarry is rock2 the marble of which our mantel-pieces are made is rock4 ,the soft sandstone of ,south ,devon1 and the hard granite of the north of ,scotland1 are alike rock4 ,the pebbles in the road are rock2 the very mould in our gardens is largely composed of crumbled rock4 ,so the word in its geological sense is a word of wide meaning4 ,now the business of the geologist is to read the history of the past in these rocks of which the earth's crust is made4 ,this may seem a singular thing to do1 and ,i can assure you it is not an easy task4 ,for1 to begin with1 the history itself is written in a strange language1 a language which man is only just beginning to spell out and understand4 ,and this is only half the difficulty with which we have to struggle4 ,if a large and learned book were put before you and you were set to read it through1 you would perhaps1 have no insurmountable difficulty1 with patience and perseverance1 in mastering its meaning4 ,but how if the book were first chopped up into pieces1 if part of it were flung away out of reach1 if part of it were crushed into a pulp1 if the numbering of the pages were in many places lost1 if the whole were mixed up in confusion1 and if then you were desired to sort1 and arrange1 and study the volume8 ,picture to yourself what sort of a task this would be1 and you will have some idea of the labors of the patient geologist4 ,rocks may be divided into several kinds or classes4 ,for the present moment it will be enough to consider the two grand divisions--,stratified rocks and ,unstratified rocks4 ,unstratified rocks are those which were once1 at a time more or less distant1 in a melted state from intense heat1 and which have since cooled into a half crystallized state2 much the same as water1 when growing colder1 cools and crystallizes into ice4 ,strictly speaking1 ice is rock1 just as much as granite and sandstone are rock4 ,water itself is of the nature of rock1 only as we commonly know it in the liquid state we do not commonly call it so4 ,illustration3 ,,unstratified ,,rock4--,a ,,volcanic ,,block4 ,crystallization means those particular forms or shapes in which the particles of a liquid arrange themselves1 as that liquid hardens into a solid--in other words1 as it freezes4 ,granite1 iron1 marble1 are frozen substances1 just as truly as ice is a frozen substance2 for with greater heat they would all become liquid like water4 ,when a liquid freezes1 there are always crystals formed1 though these are not always visible without the help of a microscope4 ,also the crystals are of different shapes with different substances4 ,if you examine the surface of a puddle or pond1 when a thin covering of ice is beginning to form1 you will be able to see plainly the delicate sharp needle-like forms of the ice crystals4 ,break a piece of ice1 and you will find that it will not easily break just in any way that you may choose1 but it will only split along the lines of these needle-like crystals4 ,this particular mode of splitting in a crystallized rock is called the cleavage of that rock4 ,crystallization may take place either slowly or rapidly1 and either in the open air or far below ground4 ,the lava from a volcano is an example of rock which has crystallized rapidly in the open air2 and granite is an example of rock which has crystallized slowly underground beneath great pressure4 ,stratified rocks1 on the contrary1 which make up a very large part of the earth's crust1 are not crystallized4 ,instead of having cooled from a liquid into a solid state1 they have been slowly built up1 bit by bit and grain upon grain1 into their present form1 through long ages of the world's history4 ,the materials of which they are made were probably once1 long1 long ago1 the crumblings from granite and other crystallized rocks1 but they show now no signs of crystallization4 ,illustration3 ,,section ,,of ,,stratified ,,rocks4 a4 ,conglomerate4 b4 ,pebbly ,sandstone1 c4 ,thin-bedded ,sandstone1 d4 ,shelly ,sandstone1 e4 ,shale4 f4 ,limestone4 ,they are called stratified because they are in themselves made up of distinct layers1 and also because they lie thus one upon another in layers1 or strata1 just as the leaves of a book lie1 or as the bricks of a house are placed4 ,throughout the greater part of ,europe1 of ,asia1 of ,africa1 of ,north and ,south ,america1 of ,australia1 these rocks are to be found1 stretching over hundreds of miles together1 north1 south1 east1 and west1 extending up to the tops of some of the earth's highest mountains1 reaching down deep into the earth's crust4 ,in many parts if you could dig straight downwards through the earth for thousands of feet1 you would come to layer after layer of these stratified rocks1 one kind below another1 some layers thick1 some layers thin1 here a stratum of gravel1 there a stratum of sandstone1 here a stratum of coal1 there a stratum of clay4 ,but how1 when1 where1 did the building up of all these rock-layers take place8 ,illustration3 ,,the ,,beach ,,in ,,the ,,foreground ,,is ,a ,,rocky ,,shelf1 ,,the ,,remnant ,,of ,,the ,,cliff ,,which ,,once ,,extended ,,out ,,to ,,the ,,island4 ,people are rather apt to think of land and water on the earth as if they were fixed in one changeless form1--as if every continent and every island were of exactly the same shape and size now that it always has been and always will be4 ,yet nothing can be further from the truth4 ,the earth-crust is a scene of perpetual change1 of perpetual struggle1 of perpetual building up1 of perpetual wearing away4 ,the work may go on slowly1 but it does go on4 ,the sea is always fighting against the land1 beating down her cliffs1 eating into her shores1 swallowing bit by bit of solid earth2 and rain and frost and inland streams are always busily at work1 helping the ocean in her work of destruction4 ,year by year and century by century it continues4 ,not a country in the world which is bordered by the open sea has precisely the same coast-line that it had one hundred years ago2 not a land in the world but parts each century with masses of its material1 washed piecemeal away into the ocean4 ,is this hard to believe8 ,look at the crumbling cliffs around old ,england's shores4 ,see the effect upon the beach of one night's fierce storm4 ,mark the pathway on the cliff1 how it seems to have crept so near the edge that here and there it is scarcely safe to tread2 and very soon1 as we know1 it will become impassable4 ,just from a mere accident1 of course1--the breaking away of some of the earth1 loosened by rain and frost and wind4 ,but this is an accident which happens daily in hundreds of places around the shores4 ,leaving the ocean1 look now at this river in our neighborhood1 and see the slight muddiness which seems to color its waters4 ,what from8 ,only a little earth and sand carried off from the banks as it flowed1--very unimportant and small in quantity1 doubtless1 just at this moment and just at this spot4 ,but what of that little going on week after week1 and century after century1 throughout the whole course of the river1 and throughout the whole course of every river and rivulet in our whole country and in every other country4 ,a vast amount of material must every year be thus torn from the land and given to the ocean4 ,for the land's loss here is the ocean's gain4 ,and1 strange to say1 we shall find that this same ocean1 so busily engaged with the help of its tributary rivers in pulling down land1 is no less busily engaged with their help in building it up4 ,you have sometimes seen directions upon a vial of medicine to shake before taking the dose4 ,when you have so shaken the bottle the clear liquid grows thick2 and if you let it stand for awhile the thickness goes off1 and a fine grain-like or dust-like substance settles down at the bottom--the settlement or sediment of the medicine4 ,the finer this sediment1 the slower it is in settling4 ,if you were to keep the liquid in gentle motion1 the fine sediment would not settle down at the bottom4 ,with coarser and heavier grains the motion would have to be quicker to keep them supported in the water4 ,now it is just the same thing with our rivers and streams4 ,running water can support and carry along sand and earth1 which in still water would quickly sink to the bottom2 and the more rapid the movement of the water1 the greater is the weight it is able to bear4 ,this is plainly to be seen in the case of a mountain torrent4 ,as it foams fiercely through its rocky bed it bears along1 not only mud and sand and gravel1 but stones and even small rocks1 grinding the latter roughly together till they are gradually worn away1 first to rounded pebbles1 then to sand1 and finally to mud4 ,the material thus swept away by a stream1 ground fine1 and carried out to sea--part being dropped by the way on the river-bed--is called detritus1 which simply means worn-out material4 ,illustration3 ,a ,,mountain ,,torrent4 ,the tremendous carrying-power of a mountain torrent can scarcely be realized by those who have not observed it for themselves4 ,i have seen a little mountain-stream swell in the course of a heavy thunderstorm to such a torrent1 brown and turbid with earth torn from the mountainside1 and sweeping resistlessly along in its career a shower of stones and rock-fragments4 ,that which happens thus occasionally with many streams is more or less the work all the year round of many more4 ,as the torrent grows less rapid1 lower down in its course1 it ceases to carry rocks and stones1 though the grinding and wearing away of stones upon the rocky bed continues1 and coarse gravel is borne still upon its waters4 ,presently the widening stream1 flowing yet more calmly1 drops upon its bed all such coarser gravel as is not worn away to fine earth1 but still bears on the lighter grains of sand4 ,next the slackening speed makes even the sand too heavy a weight1 and that in turn falls to line the river-bed1 while the now broad and placid stream carries only the finer particles of mud suspended in its waters4 ,soon it reaches the ocean1 and the flow being there checked by the incoming ocean-tide1 even the mud can no longer be held up1 and it also sinks slowly in the shallows near the shore1 forming sometimes broad mud-banks dangerous to the mariner4 ,this is the case only with smaller rivers4 ,where the stream is stronger1 the mud-banks are often formed much farther out at sea2 and more often still the river-detritus is carried away and shed over the ocean-bed1 beyond the reach of our ken4 ,the powerful rush of water in earth's greater streams bears enormous masses of sand and mud each year far out into the ocean1 there dropping quietly the gravel1 sand1 and earth1 layer upon layer at the bottom of the sea4 ,thus pulling down and building up go on ever side by side2 and while land is the theatre oftentimes of decay and loss1 ocean is the theatre oftentimes of renewal and gain4 ,did you notice the word sediment used a few pages back about the settlement at the bottom of a medicine-vial8 ,there is a second name given to the ,stratified ,rocks1 of which the earth's crust is so largely made up4 ,they are called also ,sedimentary ,rocks4 ,the reason is simply this4 ,the ,stratified ,rocks of the present day were once upon a time made up out of the sediment stolen first from land and then allowed to settle down on the sea-bottom4 ,long1 long ago1 the rivers1 the streams1 the ocean1 were at work1 as they are now1 carrying away rock and gravel1 sand and earth4 ,then1 as now1 all this material1 borne upon the rivers1 washed to and fro by the ocean1 settled down at the mouths of rivers or at the bottom of the sea1 into a sediment1 one layer forming over another1 gradually built up through long ages4 ,at first it was only a soft1 loose1 sandy or muddy sediment1 such as you may see on the seashore1 or in a mud-bank4 ,but as the thickness of the sediment increased1 the weight of the layers above gradually pressed the lower layers into firm hard rocks2 and still1 as the work of building went on1 these layers were1 in their turn1 made solid by the increasing weight over them4 ,certain chemical changes had also a share in the transformation from soft mud to hard rock1 which need not be here considered4 ,all this has through thousands of years been going on4 ,the land is perpetually crumbling away2 and fresh land under the sea is being perpetually built up1 from the very same materials which the sea and the rivers have so mercilessly stolen from continents and islands4 ,this is the way1 if geologists rightly judge1 in which a very large part of the enormous formations of ,stratified or ,sedimentary ,rocks have been made4 ,illustration3 ,,view ,,in ,a ,,canon4 ,so far is clear4 ,but now we come to a difficulty4 ,the ,stratified ,rocks1 of which a very large part of the continents is made1 appear to have been built up slowly1 layer upon layer1 out of the gravel1 sand1 and mud1 washed away from the land and dropped on the shore of the ocean4 ,illustration3 ,,sea ,,cliffs ,,showing ,a ,,series ,,of ,,stratified ,,rocks4 ,you may see these layers for yourself as you walk out into the country4 ,look at the first piece of bluff rock you come near1 and observe the clear pencil-like markings of layer above layer--not often indeed lying flat1 one over another1 and this must be explained later1 but however irregularly slanting1 still plainly visible4 ,you can examine these lines of stratification on the nearest cliff1 the nearest quarry1 the nearest bare headland1 in your neighborhood4 ,but how can this be8 ,if all these stratified rocks are built on the floor of the ocean out of material taken from the land1 how can we by any possibility find such rocks upon the land8 ,in the beds of rivers we might indeed expect to see them1 but surely nowhere else save under ocean waters4 ,yet find them we do4 ,through ,england1 through the two great world-continents1 they abound on every side4 ,thousands of miles in unbroken succession are composed of such rocks4 ,stand with me near the seashore1 and let us look around4 ,those white chalk cliffs--they1 at least1 are not formed of sand or earth4 ,true1 and the lines of stratification are in them very indistinct1 if seen at all2 yet they too are built up of sediment of a different kind1 dropping upon ocean's floor4 ,see1 however1 in the rough sides of yonder bluff the markings spoken of1 fine lines running alongside of one another1 sometimes flat1 sometimes bent or slanting1 but always giving the impression of layer piled upon layer4 ,yet how can one for a moment suppose that the ocean-waters ever rose so high8 ,stay a moment4 ,look again at yonder white chalk cliff1 and observe a little way below the top a singular band of shingles1 squeezed into the cliff1 as it were1 with chalk below and earth above4 ,that is believed to be an old sea-beach4 ,once upon a time the waters of the sea are supposed to have washed those shingles1 as now they wash the shore near which we stand1 and all the white cliff must have lain then beneath the ocean4 ,geologists were for a long while sorely puzzled to account for these old sea-beaches1 found high up in the cliffs around our land in many different places4 ,they had at first a theory that the sea must once1 in far back ages1 have been a great deal higher than it is now4 ,but this explanation only brought about fresh difficulties4 ,it is quite impossible that the level of the sea should be higher in one part of the world than in another4 ,if the sea around ,england were then one or two hundred feet higher than it is now1 it must have been one or two hundred feet higher in every part of the world where the ocean-waters have free flow4 ,one is rather puzzled to know where all the water could have come from1 for such a tremendous additional amount4 ,besides1 in some places remains of sea-animals are found in mountain heights1 as much as two or three thousand feet above the sea-level--as1 for instance1 in ,corsica4 ,this very much increases the difficulty of the above explanation4 ,so another theory was started instead1 and this is now generally supposed to be the true one4 ,what if instead of the whole ocean having been higher1 parts of the land were lower8 ,england at one time1 parts of ,europe at another time1 parts of ,asia and ,america at other times1 may have slowly sunk beneath the ocean1 and after long remaining there have slowly risen again4 ,this is by no means so wild a supposition as it may seem when first heard1 and as it doubtless did seem when first proposed4 ,for even in the present day these movements of the solid crust of our earth are going on4 ,the coasts of ,sweden and ,finland have long been slowly and steadily rising out of the sea1 so that the waves can no longer reach so high upon those shores as in years gone by they used to reach4 ,in ,greenland1 on the contrary1 land has long been slowly and steadily sinking1 so that what used to be the shore now lies under the sea4 ,other such risings and sinkings might be mentioned1 as also many more in connection with volcanoes and earthquakes1 which are neither slow nor steady1 but sudden and violent4 ,so it becomes no impossible matter to believe that1 in the course of ages past1 all those wide reaches of our continents and islands1 where sedimentary rocks are to be found1 were each in turn1 at one time or another1 during long periods1 beneath the rolling waters of the ocean4444 99 99 99 99 99 ,these built-up rocks are not only called ,stratified1 and ,sedimentary4 ,they have also the name of ,aqueous ,rock1 from the ,latin word aqua1 water2 because they are believed to have been formed by the action of the water4 ,they have yet another and fourth title1 which is1 ,fossiliferous ,rocks4 ,fossils are the hardened remains of animals and vegetables found in rocks4 ,they are rarely1 if ever1 seen in unstratified rocks2 but many layers of stratified rocks abound in these remains4 ,whole skeletons as well as single bones1 whole tree-trunks as well as single leaves1 are found thus embedded in rock-layers1 where in ages past the animal or plant died and found a grave4 ,they exist by thousands in many parts of the world1 varying in size from the huge skeleton of the elephant to the tiny shell of the microscopic animalcule4 ,illustration3 ,,fossil ,,of ,,carboniferous ,,fern4 ,fossils differ greatly in kind4 ,sometimes the entire shell or bone is changed into stone1 losing all its animal substance1 but retaining its old outline and its natural markings4 ,sometimes the fossil is merely the hardened impress of the outside of a shell or leaf1 which has dented its picture on soft clay1 and has itself disappeared1 while the soft clay has become rock1 and the indented picture remains fixed through after-centuries4 ,sometimes the fossil is the cast of the inside of a shell2 the said shell having been filled with soft mud1 which has taken its exact shape and hardened1 while the shell itself has vanished4 ,the most complete description of fossil is the first of these three kinds4 ,it is wonderfully shown sometimes in fossil wood1 where all the tiny cells and delicate fibres remain distinctly marked as of old1 only the whole woody substance has changed into hard stone4 ,illustration3 ,,footprints ,,from ,,triassic ,,sandstone ,,of ,,connecticut4 ,but although the fossil remains of quadrupeds and other land-animals are found in large quantities1 their number is small compared with the enormous number of fossil sea-shells and sea-animals4 ,illustration3 ,,fossil ,,footprints4 ,land-animals can1 as a rule1 have been so preserved1 only when they have been drowned in ponds or rivers1 or mired in bogs and swamps1 or overtaken by frost1 or swept out to sea4 ,sea-animals1 on the contrary1 have been so preserved on land whenever that land has been under the sea2 and this appears to have been the case1 at one or another past age1 with the greater part of our present continents4 ,these fossil remains of sea-animals are discovered in all quarters of the world1 not only on the seashore but also far inland1 not only deep down underground but also high up on the tops of lofty mountains--a plain proof that over the summits of those mountains the ocean must once have rolled1 and this not for a brief space only1 but through long periods of time4 ,and not on the mountain-summit only are these fossils known to abound1 but sometimes in layer below layer of the mountain1 from top to bottom1 through thousands of feet of rock4 ,illustration3 ,,fossil ,,shells4 ,this may well seem puzzling at first sight4 ,fossils of sea-creatures on a mountain-top are startling enough2 yet hardly so startling as the thought of fossils inside that mountain4 ,how could they have found their way thither8 ,the difficulty soon vanishes1 if once we clearly understand that all these thousands of feet of rock were built up slowly1 layer after layer1 when portions of the land lay deep under the sea4 ,thus each separate layer of mud or sand or other material became in its turn the top layer1 and was for the time the floor of the ocean1 until further droppings of material out of the waters made a fresh layer1 covering up the one below4 ,while each layer was thus in succession the top layer of the building1 and at the same time the floor of the ocean1 animals lived and died in the ocean1 and their remains sank to the bottom1 resting upon the sediment floor4 ,thousands of such dead remains disappeared1 crumbling into fine dust and mingling with the waters1 but here and there one was caught captive by the half-liquid mud1 and was quickly covered and preserved from decay4 ,and still the building went on1 and still layer after layer was placed1 till many fossils lay deep down beneath the later-formed layers2 and when at length1 by slow or quick upheaval of the ground1 this sea-bottom became a mountain1 the little fossils were buried within the body of that mountain4 ,so wondrously the matter appears to have come about4 99 99 99 99 99 ,another difficulty with respect to the stratified rocks has to be thought of4 ,all these layers or deposits of gravel1 sand1 or earth1 on the floor of the ocean1 would naturally be horizontal--that is1 would lie flat1 one upon another4 ,in places the ocean-floor might slant1 or a crevice or valley or ridge might break the smoothness of the deposit4 ,but though the layers might partake of the slant1 though the valley might have to be filled1 though the ridge might have to be surmounted1 still the general tendency of the waves would be to level the dropping deposits into flat layers4 ,then how is it that when we examine the strata of rocks in our neighborhood1 wherever that neighborhood may be1 we do not find them so arranged8 ,here1 it is true1 the lines for a space are nearly horizontal1 but there1 a little way farther on1 they are perpendicular2 here they are bent1 and there curved2 here they are slanting1 and there crushed and broken4 ,this only bears out what has been already said about the ,book of ,geology4 ,it has been bent and disturbed1 crushed and broken4 ,great powers have been at work in this crust of our earth4 ,continents have been raised1 mountains have been upheaved1 vast masses of rock have been scattered into fragments4 ,here or there we may find the layers arranged as they were first laid down2 but far more often we discover signs of later disturbance1 either slow or sudden1 varying from a mere quiet tilting to a violent overturn4 ,illustration3 ,,example ,,of ,,disturbance ,,of ,,the ,,earth',s ,,layers4 ,so the ,book of ,geology is a torn and disorganized volume1 not easy to read4 ,yet1 on the other hand1 these very changes which have taken place are a help to the geologist4 ,it may seem at first sight as if we should have an easier task1 if the strata were all left lying just as they were first formed1 in smooth level layers1 one above another4 ,but if it were so1 we could know very little about the lower layers4 ,we might indeed feel sure1 as we do now1 that the lowest layers were the oldest and the top layers the newest1 and that any fossils found in the lower layers must belong to an age farther back than any fossils found in the upper layers4 ,so much would be clear4 ,and we might dig also and burrow a little way down1 through a few different kinds of rock1 where they were not too thick4 ,but that would be all4 ,there our powers would cease4 ,now how different4 ,through the heavings and tiltings of the earth's crust1 the lower layers are often pushed quite up to the surface1 so that we are able to examine them and their fossils without the least difficulty1 and very often without digging underground at all4 ,you must not suppose that the real order of the rocks is changed by these movements1 for generally speaking it is not4 ,the lower kinds are rarely if ever found placed over the upper kinds2 only the ends of them are seen peeping out above ground4 ,it is as if you had a pile of copy-books lying flat one upon another1 and were to put your finger under the lowest and push it up4 ,all those above would be pushed up also1 and perhaps they would slip a little way down1 so that you would have a row of edges showing side by side1 at very much the same height4 ,the arrangement of the copy-books would not be changed1 for the lowest would still be the lowest in actual position2 but a general tilting or upheaval would have taken place4 ,just such a tilting or upheaval has taken place again and again with the rocks forming our earth-crust4 ,the edges of the lower rocks often show side by side with those of higher layers4 ,but geologists know them apart4 ,they are able to tell confidently whether such and such a rock1 peeping out at the earth's surface1 belongs really to a lower or a higher kind4 ,for there is a certain sort of order followed in the arrangement of rock-layers all over the earth1 and it is well known that some rocks are never found below some other rocks1 that certain particular kinds are never placed above certain other kinds4 ,thus it follows that the fossils found in one description of rock1 must be the fossils of animals which lived and died before the animals whose fossil remains are found in another neighboring rock1 just because this last rock-layer was built upon the ocean-floor above and therefore later than the other4 ,all this is part of the foreign language of geology--part of the piecing and arranging of the torn volume4 ,many mistakes are made2 many blunders are possible2 but the mistakes and blunders are being gradually corrected1 and certain rules by which to read and understand are becoming more and more clear4 ,it has been already said that unstratified rocks are those which have been at some period1 whether lately or very long ago1 in a liquid state from intense heat1 and which have since cooled1 either quickly or slowly1 crystallizing as they cooled4 ,unstratified ,rocks may be divided into two distinct classes4 ,illustration3 ,,section ,,of ,a ,,lava ,,bomb4 ,first4--,volcanic ,rocks1 such as lava4 ,these have been quickly cooled at the surface of the earth1 or not far below it4 ,secondly4--,plutonic ,rocks1 such as granite4 ,these have been slowly cooled deep down in the earth under heavy pressure4 ,there is also a class of rocks1 called metamorphic rocks1 including some kinds of marble4 ,these are1 strictly speaking1 crystalline rocks1 and yet they are arranged in something like layers4 ,the word metamorphic simply means transformed4 ,they are believed to have been once stratified rocks1 perhaps containing often the remains of animals2 but intense heat has later transformed them into crystalline rocks1 and the animal remains have almost or quite vanished4 ,illustration3 ,,lava-,,stream ,,on ,,vesuvius4 ,just as the different kinds of ,stratified ,rocks are often called ,aqueous ,rocks1 or rocks formed by the action of water--so these different kinds of ,unstratified ,rocks are often called ,igneous ,rocks1 or rocks formed by the action of fire--the name being taken from the ,latin word for fire4 ,the ,metamorphic ,rocks are sometimes described as ,aqueo-igneous1 since both water and fire helped in the forming of them4 ,it was at one time believed1 as a matter of certainty1 that granite and such rocks belonged to a period much farther back than the periods of the stratified rocks4 ,that is to say1 it was supposed that fire-action had come first and water-action second2 that the fire-made rocks were all formed in very early ages1 and that only water-made rocks still continued to be formed4 ,so the name of ,primary ,rocks1 or ,first ,rocks1 was given to the granites and other such rocks1 and the name of ,secondary ,rocks to all water-built rocks2 while those of the third class were called ,transition ,rocks1 because they seemed to be a kind of link or stepping-stone in the change from the ,first to the ,second ,rocks4 ,the chief reason for the general belief that fire-built rocks were older than water-built ones was1 that the former are as a rule found to lie lower than the latter4 ,they form1 as it were1 the basement of the building1 while the top-stories are made of water-built rocks4 ,many still believe that there is much truth in the thought4 ,it is most probable1 so far as we are able to judge1 that the first-formed crust of rocks all over the earth was of cooled and crystallized material4 ,as these rocks were crumbled and wasted by the ocean1 materials would have been supplied for the building-up of rocks1 layer upon layer4 ,but this is conjecture4 ,we cannot know with any certainty the course of events so far back in the past4 ,and geologists are now able to state with tolerable confidence that1 however old many of the granites may be1 yet a large amount of the fire-built rocks are no older than the water-built rocks which lie over them4 ,so by many geologists the names of ,primary1 ,transition1 and ,secondary ,formations are pretty well given up4 ,it has been proposed to give instead to the crystallized rocks of all kinds the name of ,underlying ,rocks 7,hypogene ,rocks74 ,but if they really do lie under1 how can they possibly be of the same age8 ,one would scarcely venture to suppose1 in looking at a building1 that the cellars had not been finished before the upper floors4 ,true4 ,in the first instance doubtless the cellars were first made1 then the ground-floor1 then the upper stories4 ,when1 however1 the house was so built1 alterations and improvements might be very widely carried on above and below4 ,while one set of workmen were engaged in remodelling the roof1 another set of workmen might be engaged in remodelling the kitchens and first floor1 pulling down1 propping up1 and actually rebuilding parts of the lower walls4 ,this is precisely what the two great fellow-workmen1 ,fire and ,water1 are ever doing in the crust of our earth4 ,and if it be objected that such alterations too widely undertaken might result in slips1 cracks1 and slidings1 of ceilings and walls in the upper stories1 ,i can only say that such catastrophes have been the result of underground alterations in that great building1 the earth's crust4444 ,we see therefore clearly that1 although the earliest fire-made rocks may very likely date farther back than the earliest water-made rocks1 yet the making of the two kinds has gone on side by side1 one below and the other above ground1 through all ages up to the present moment4 ,and just as in the present day water continues its busy work above ground of pulling down and building up1 so also fire continues its busy work underground of melting rocks which afterwards cool into new forms1 and also of shattering and upheaving parts of the earth-crust4 ,for there can be no doubt that fiery heat does exist as a mighty power within our earth1 though to what extent we are not able to say4 ,these two fellow-workers in nature have different modes of working4 ,one we can see on all sides1 quietly progressing1 demolishing land patiently bit by bit1 building up land steadily grain by grain4 ,the other1 though more commonly hidden from sight1 is fierce and tumultuous in character1 and shows his power in occasional terrific outbursts4 ,we can scarcely realize what the power is of the imprisoned fiery forces underground1 though even we are not without some witness of their existence4 ,from time to time even our firm land has been felt to tremble with a thrill from some far-off shock2 and even in our country is seen the marvel of scalding water pouring unceasingly from deep underground4444 ,think of the tremendous eruptions of ,vesuvius1 of ,etna1 of ,hecla1 of ,mauna ,loa4 ,think of whole towns crushed and buried1 with their thousands of living inhabitants4 ,think of rivers of glowing lava streaming up from regions below ground1 and pouring along the surface for a distance of forty1 fifty1 and even sixty miles1 as in ,iceland and ,hawaii4 ,think of red-hot cinders flung from a volcano-crater to a height of ten thousand feet4 ,think of lakes of liquid fire in other craters1 five hundred to a thousand feet across1 huge cauldrons of boiling rock4 ,think of showers of ashes from the furnace below of yet another1 borne so high aloft as to be carried seven hundred miles before they sank to earth again4 ,think of millions of red-hot stones flung out in one eruption of ,vesuvius4 ,think of a mass of rock1 one hundred cubic yards in size1 hurled to a distance of eight miles or more out of the crater of ,cotopaxi4 ,illustration3 ,,hot ,,wells4 ,think also of earthquake-shocks felt through twelve hundred miles of country4 ,think of fierce tremblings and heavings lasting in constant succession through days and weeks of terror4 ,think of hundreds of miles of land raised several feet in one great upheaval4 ,think of the earth opening in scores of wide-lipped cracks1 to swallow men and beasts4 ,think of hot mud1 boiling water1 scalding stream1 liquid rock1 bursting from such cracks1 or pouring from rents in a mountain-side4 ,truly these are signs of a state of things in or below the solid crust on which we live1 that may make us doubt the absolute security of ,mother ,earth4 ,different explanations have been put forward to explain this seemingly fiery state of things underground4 ,until lately the belief was widely held that our earth was one huge globe of liquid fire1 with only a slender cooled crust covering her1 a few miles in thickness4 ,this view was supported by the fact that heat is found to increase as men descend into the earth4 ,measurements of such heat-increase have been taken1 both in mines and in borings for wells4 ,the usual rate is about one degree more of heat1 of our common thermometer1 for every fifty or sixty feet of descent4 ,if this were steadily continued1 water would boil at a depth of eight thousand feet below the surface2 iron would melt at a depth of twenty-eight miles2 while at a depth of forty or fifty miles no known substance upon earth could remain solid4 ,the force of this proof is1 however1 weakened by the fact that the rate at which the heat increases differs very much in different places4 ,also it is now generally supposed that such a tremendous furnace of heat--a furnace nearly eight thousand miles in diameter--could not fail to break up and melt so slight a covering shell4 ,many believe1 therefore1 not that the whole interior of the earth is liquid with heat1 but that enormous fire-seas or lakes of melted rock exist here and there1 under or in the earth-crust4 ,from these lakes the volcanoes would be fed1 and they would be the cause of earthquakes and land-upheavals or land-sinkings4 ,there are strong reasons for supposing that the earth was once a fiery liquid body1 and that she has slowly cooled through long ages4 ,some hold that her centre probably grew solid first from tremendous pressure2 that her crust afterwards became gradually cold2 and that between the solid crust and the solid inside or nucleus1 a sea of melted rock long existed1 the remains of which are still to be found in these tremendous fiery reservoirs4 ,the idea accords well with the fact that large numbers of extinct or dead volcanoes are scattered through many parts of the earth4 ,if the above explanation be the right one1 doubtless the fire-seas in the crust extended once upon a time beneath such volcanoes1 but have since died out or smouldered low in those parts4 ,a somewhat curious calculation has been made1 to illustrate the different modes of working of these two mighty powers--,fire and ,water4 ,the amount of land swept away each year in mud1 and borne to the ocean by the ,river ,ganges1 was roughly reckoned1 and also the amount of land believed to have been upheaved several feet in the great ,chilian earthquake4 ,it was found that the river1 steadily working month by month1 would require some four hundred years to carry to the sea the same weight of material1 which in one tremendous effort was upheaved by the fiery underground forces4 ,yet we must not carry this distinction too far4 ,fire does not always work suddenly1 or water slowly2 witness the slow rising and sinking of land in parts of the earth1 continuing through centuries2 and witness also the effects of great floods and storms4 ,the crust of the earth is made of rock4 ,but what is rock made of8 ,certain leading divisions of rocks have been already considered3 ,the ,water-made ,rocks2 ,the ,fire-made ,rocks1 both ,plutonic and ,volcanic2 ,the ,water-and-,fire-made ,rocks4 ,the first of these--,water-made ,rocks--may be subdivided into three classes4 ,these are1-- ,i4 ,flint ,rocks2 ,,ii4 ,clay ,rocks2 ,,iii4 ,lime ,rocks4 ,this is not a book in which it would be wise to go closely into the mineral nature of rocks4 ,two or three leading thoughts may1 however1 be given4 ,does it not seem strange that the hard and solid rocks should be in great measure formed of the same substances which form the thin invisible air floating around us8 ,yet so it is4 ,there is a certain gas called ,oxygen ,gas4 ,without that gas you could not live many minutes4 ,banish it from the room in which you are sitting1 and in a few minutes you will die4 ,this gas makes up nearly one-quarter by weight of the atmosphere round the whole earth4 ,the same gas plays an important part in the ocean2 for more than three-quarters of water is oxygen4 ,it plays also an important part in rocks2 for about half the material of the entire earth's crust is oxygen4 ,another chief material in rocks is silicon4 ,this makes up one-quarter of the crust1 leaving only one-quarter to be accounted for4 ,silicon mixed with oxygen makes silica or quartz4 ,there are few rocks which have not a large amount of quartz in them4 ,common flint1 sandstones1 and the sand of our shores1 are made of quartz1 and therefore belong to the first class of ,silicious or ,flint ,rocks4 ,granites and lavas are about one-half quartz4 ,the beautiful stones1 amethyst1 agate1 chalcedony1 and jasper1 are all different kinds of quartz4 ,another chief material in rocks is a white metal called aluminium4 ,united to oxygen it becomes alumina1 the chief substance in clay4 ,rocks of this kind--such as clays1 and also the lovely blue gem1 sapphire--are called ,argillaceous ,rocks1 from the ,latin word for clay1 and belong to the second class4 ,such rocks keep fossils well4 ,another is calcium4 ,united to oxygen and carbonic acid1 it makes carbonate of lime1 the chief substance in limestone2 so all limestones belong to the third class of ,calcareous or ,lime ,rocks4 ,other important materials may be mentioned1 such as magnesium1 potassium1 sodium1 iron1 carbon1 sulphur1 hydrogen1 chlorine1 nitrogen4 ,these1 with many more1 not so common1 make up the remaining quarter of the earth-crust4 ,carbon plays as important a part in animal and vegetable life as silicon in rocks4 ,carbon is most commonly seen in three distinct forms--as charcoal1 as black-lead1 and as the pure brilliant diamond4 ,carbon united1 in a particular proportion1 to oxygen1 forms carbonic acid2 and carbonic acid united1 in a particular proportion1 to lime1 forms limestone4 ,hydrogen united to oxygen forms water4 ,each of these two gases is invisible alone1 but when they meet and mingle they form a liquid4 ,nitrogen united to oxygen and to a small quantity of carbonic acid gas forms our atmosphere4 ,rocks of pure flint1 pure clay1 or pure lime1 are rarely or never met with4 ,most rocks are made up of several different substances melted together4 99 99 99 99 99 ,in the fire-built rocks no remains of animals are found1 though in water-built rocks they abound4 ,water-built rocks are sometimes divided into two classes--those which only contain occasional animal remains1 and those which are more or less built up of the skeletons of animals4 ,illustration3 ,,amiba ,,princeps1 ,,one ,,of ,,the ,,many ,,orders ,,of ,,the ,,rhizopoda ,,class1 ,,magnified ,,one ,,hundred ,,times4 ,there are some exceedingly tiny creatures inhabiting the ocean1 called ,rhizopods4 ,they live in minute shells1 the largest of which may be almost the size of a grain of wheat1 but by far the greater number are invisible as shells without a microscope1 and merely show as fine dust4 ,the rhizopods are of different shapes1 sometimes round1 sometimes spiral1 sometimes having only one cell1 sometimes having several cells4 ,in the latter case a separate animal lives in each cell4 ,the animal is of the very simplest as well as the smallest kind4 ,he has not even a mouth or a stomach but can take in food at any part of his body4 ,illustration3 ,,rhizopods 7,,magnified74 ,these rhizopods live in the oceans in enormous numbers4 ,tens of millions are ever coming into existence1 living out their tiny lives1 dying1 and sinking to the bottom4 ,there upon the ocean-floor gather their remains1 a heaped-up multitude of minute skeletons or shells1 layer forming over layer4 ,it was long suspected that the white chalk cliffs of ,england were built up in some such manner as this through past ages4 ,and now at length proof has been found1 in the shape of mud dredged up from the ocean-bottom--mud entirely composed of countless multitudes of these little shells1 dropping there by myriads1 and becoming slowly joined together in one mass4 ,just so1 it is believed1 were the white chalk cliffs built--gradually prepared on the ocean-floor1 and then slowly or suddenly upheaved1 so as to become a part of the dry land4 ,think what the enormous numbers must have been of tiny living creatures1 out of whose shells the wide reaches of white chalk cliffs have been made4 ,chalk cliffs and chalk layers extend from ,ireland1 through ,england and ,france1 as far as to the ,crimea4 ,in the south of ,russia they are said to be six hundred feet thick4 ,yet one cubic inch of chalk is calculated to hold the remains of more than one million rhizopods4 ,how many countless millions upon millions must have gone to the whole structure6 ,how long must the work of building up have lasted6 ,illustration3 ,,three ,,polyps ,,of ,,coral4 ,these little shells do not always drop softly and evenly to the ocean-floor1 to become quietly part of a mass of shells4 ,sometimes1 where the ocean is shallow enough for the waves to have power below1 or where land currents can reach1 they are washed about1 and thrown one against another1 and ground into fine powder2 and the fine powder becomes in time1 through different causes1 solid rock4 ,illustration3 ,,coral ,,polyp4 ,limestone is made in another way also4 ,in the warm waters of the ,south ,pacific ,ocean there are many islands1 large and small1 which have been formed in a wonderful manner by tiny living workers4 ,the workers are soft jelly-like creatures1 called polyps1 who labor together in building up great walls and masses of coral4 ,illustration3 ,,coral ,,island4 ,illustration3 ,,young ,,coral ,,polyp ,,attached ,,to ,a ,,rock ,,and ,,expanded4 ,they never carry on their work above the surface of the water1 for in the air they would die4 ,but the waves break the coral1 and heap it up above high-water mark1 and carry earth and seeds to drop there till at length a small low-lying island is formed4 ,the waves not only heap up broken coral1 but they grind the coral into fine powder1 and from this powder limestone rock is made1 just as it is from the powdered shells of rhizopods4 ,the material used by the polyps in building the coral is chiefly lime1 which they have the power of gathering out of the water1 and the fine coral-powder1 sinking to the bottom1 makes large quantities of hard limestone4 ,soft chalk is rarely1 if ever1 found near the coral islands4 ,illustration3 #a4 ,,white ,,coral4 #b4 ,,portion ,,of ,a ,,branch 7,,magnified74 ,limestones are formed in the same manner from the grinding up of other sea-shells and fossils1 various in kind2 the powder becoming gradually united into solid rock4 ,there is yet another way in which limestone is made1 quite different from all these4 ,sometimes streams of water have a large quantity of lime in them2 and these as they flow will drop layers of lime which harden into rock4 ,or a lime-laden spring1 making its way through the roof of an underground cavern1 will leave all kinds of fantastic arrangements of limestone wherever its waters can trickle and drip4 ,such a cavern is called a stalactite cave4 99 99 99 99 99 ,so there are different kinds of fossil rock-making4 ,there may be rocks made of other materials1 with fossil simply buried in them4 ,there may be rocks made entirely of fossils1 which have gathered in masses as they sank to the sea-bottom1 and have there become simply and lightly joined together4 ,there may be rocks made of the ground-up powder of fossils1 pressed into a solid substance or united by some other substance4 ,rocks are also often formed of whole fossils1 or stones1 or shells1 bound into one by some natural soft sticky cement1 which has gathered round them and afterwards grown hard1 like the cement which holds together the stones in a wall4 ,the tiny rhizopods 7meaning root foot7 which have so large a share in chalk and limestone making1 are among the smallest and simplest known kinds of animal life4 ,there are also some very minute forms of vegetable life1 which exist in equally vast numbers1 called ,diatoms4 ,for a long while they were believed to be living animals1 like the rhizopods4 ,scientific men are now1 however1 pretty well agreed that they really are only vegetables or plants4 ,the diatoms have each one a tiny shell or shield1 not made of lime like the rhizopod-shells1 but of flint4 ,some think that common flint may be formed of these tiny shells4 ,again1 there is a kind of rock called ,mountain ,meal1 which is entirely made up of the remains of diatoms4 ,examined under the microscope1 thousands of minute flint shields of various shapes are seen4 ,this rock1 or earth1 is very abundant in many places1 and is sometimes used as a polishing powder4 ,in ,bohemia there is a layer of it no less than fourteen feet thick4 ,yet so minute are the shells of which it is composed1 that one square inch of rock is said to contain about four thousand millions of them4 ,each one of these millions is a separate distinct fossil4444 99 99 99 99 99 ,illustration3 ,,succession ,,of ,,buried ,,coal-,,growths ,,and ,,erect ,,tree-,,stumps4 ,,sydney1 ,,cape ,,breton4 a4 ,sandstone1 b4 ,shales1 c4 ,coal-seams1 d4 ,bed containing ,roots and ,stumps in situ4 ,if you examine carefully a piece of coal1 you will find1 more or less clearly1 markings like those which are seen in a piece of wood4 ,sometimes they are very distinct indeed4 ,coal abounds in impressions of leaves1 ferns1 and stems1 and fossil remains of plants and tree-trunks are found in numbers in coal-seams4 ,coal is a vegetable substance4 ,the wide coal-fields of ,britain and other lands are the fossil remains of vast forests4 ,long ages ago1 as it seems1 broad and luxuriant forests flourished over the earth4 ,in many parts generation after generation of trees lived and died and decayed1 leaving no trace of their existence1 beyond a little layer of black mould1 soon to be carried away by wind and water4 ,coal could only be formed where there were bogs and quagmires4 ,but in bogs and quagmires1 and in shallow lakes of low-lying lands1 there were great gatherings of slowly-decaying vegetable remains1 trees1 plants1 and ferns all mingling together4 ,then after a while the low lands would sink and the ocean pouring in would cover them with layers of protecting sand or mud2 and sometimes the land would rise again1 and fresh forests would spring into life1 only to be in their turn overwhelmed anew1 and covered by fresh sandy or earthy deposits4 ,these buried forests lay through the ages following1 slowly hardening into the black and shining coal1 so useful now to man4 ,the coal is found thus in thin or thick seams1 with other rock-layers between1 telling each its history of centuries long past4 ,in one place no less than sixteen such beds of coal are found1 one below another1 each divided from the next above and the next underneath by beds of clay or sand or shale4 ,the forests could not have grown in the sea1 and the earth-layers could not have been formed on land1 therefore many land-risings and sinkings must have taken place4 ,each bed probably tells the tale of a succession of forests4444 99 99 99 99 99 ,before going on to a sketch of the early ages of the ,earth's history--ages stretching back long long before the time of ,adam--it is needful to think yet for a little longer about the manner in which that history is written1 and the way in which it has to be read4 ,for the record is one difficult to make out1 and its style of expression is often dark and mysterious4 ,there is scarcely any other volume in the great ,book of ,nature1 which the student is so likely to misread as this one4 ,it is very needful1 therefore1 to hold the conclusions of geologists with a light grasp1 guarding each with a perhaps or a may be4 ,many an imposing edifice has been built1 in geology1 upon a rickety foundation which has speedily given way4 ,in all ages of the world's history up to the present day1 rock-making has taken place--fire-made rocks being fashioned underground1 and water-made rocks being fashioned above ground though under water4 ,also in all ages different kinds of rocks have been fashioned side by side--limestone in one part of the world1 sandstone in another1 chalk in another1 clay in another1 and so on4 ,there have1 it is true1 been ages when one kind seems to have been the chief kind--an age of limestone1 or an age of chalk4 ,but even then there were doubtless more rock-buildings going on1 though not to so great an extent4 ,on the other hand1 there may have been ages during which no limestone was made1 or no chalk1 or no clay4 ,as a general rule1 however1 the various sorts of rock-building have probably gone on together4 ,this was not so well understood by early geologists as it is now4 ,the difficulty is often great of disentangling the different strata1 and saying which was earlier and which later formed4 ,still1 by close and careful study of the rocks which compose the earth's crust1 a certain kind of order is found to exist1 more or less followed out in all parts of the world4 ,when each layer was formed in ,england or in ,america1 the geologist cannot possibly say4 ,he can1 however1 assert1 in either place1 that a certain mass of rock was formed before a certain other mass in that same place1 even though the two may seem to lie side by side2 for he knows that they were so placed only by upheaval1 and that once upon a time the one lay beneath the other4 ,the geologist can go further4 ,he can often declare that a certain mass of rock in ,america and a certain mass of rock in ,england1 quite different in kind1 were probably built up at about the same time4 ,how long ago that time was he would be rash to attempt to say2 but that the two belong to the same age he has good reason for supposing4 ,we find rocks piled upon rocks in a certain order1 so that we may generally be pretty confident that the lower rocks were first made1 and the upper rocks the latest built4 ,further than this1 we find in all the said layers of water-built rocks signs of past life4 ,as already stated1 much of this life was ocean-life1 though not all4 ,below the sea1 as the rock-layers were being formed1 bit by bit1 of earth dropping from the ocean to the ocean's floor1 sea-creatures lived out their lives and died by thousands1 to sink to that same floor4 ,millions passed away1 dissolving and leaving no trace behind2 but thousands were preserved--shells often1 animals sometimes4 ,nor was this all4 ,for now and again some part of the sea-bottom was upheaved1 slowly or quickly1 till it became dry land4 ,on this dry land animals lived again1 and thousands of them1 too1 died1 and their bones crumbled into dust4 ,but here and there one was caught in bog or frost1 and his remains were preserved till1 through lapse of ages1 they turned to stone4 ,yet again that land would sink1 and over it fresh layers were formed by the ocean-waters1 with fresh remains of sea-animals buried in with the layers of sand or lime2 and once more the sea-bottom would rise1 perhaps then to continue as dry land1 until the day when man should discover and handle these hidden remains4 ,now note a remarkable fact as to these fossils1 scattered far and wide through the layers of stratified rock4 ,in the uppermost and latest built rocks the animals found are the same1 in great measure1 as those which now exist upon the earth4 ,leaving the uppermost rocks1 and examining those which lie a little way below1 we find a difference4 ,some are still the same1 and others1 if not quite the same1 are very much like what we have now2 but here and there a creature of a different form appears4 ,go deeper still1 and the kinds of animals change further4 ,fewer and fewer resemble those which now range the earth2 more and more belong to other species4 ,descend through layer after layer till we come to rocks built in earliest ages and not one fossil shall we find precisely the same as one animal living now4 ,so not only are the rocks built in successive order1 stratum after stratum belonging to age after age in the past1 but fossil-remains also are found in successive order1 kind after kind belonging to past age after age4 ,although in the first instance the succession of fossils was understood by means of the succession of rock-layers1 yet in the second place the arrangement of rock-layers is made more clear by the means of these very fossils4 ,a geologist1 looking at the rocks in ,america1 can say which there were first-formed1 which second-formed1 which third-formed4 ,also1 looking at the rocks in ,england1 he can say which there were first-formed1 second-formed1 third-formed4 ,he would1 however1 find it very difficult1 if not impossible1 to say which among any of the ,american rocks was formed at about the same time as any particular one among the ,english rocks1 were it not for the help afforded him by these fossils4 ,just as the regular succession of rock-strata has been gradually learned1 so the regular succession of different fossils is becoming more and more understood4 ,it is now known that some kinds of fossils are always found in the oldest rocks1 and in them only2 that some kinds are always found in the newest rocks1 and in them only2 that some fossils are rarely or never found lower than certain layers2 that some fossils are rarely or never found higher than certain other layers4 ,so this fossil arrangement is growing into quite a history of the past4 ,and a geologist1 looking at certain rocks1 pushed up from underground1 in ,england and in ,america1 can say3 ,these are very different kinds of rocks1 it is true1 and it would be impossible to say how long the building up of the one might have taken place before or after the other4 ,but ,i see that in both these rocks there are exactly the same kinds of fossil-remains1 differing from those in the rocks above and below4 ,i conclude therefore that the two rocks belong to about the same great age in the world's past history1 when the same animals were living upon the earth4 ,observing and reasoning thus1 geologists have drawn up a general plan or order of strata2 and the whole of the vast masses of water-built rocks throughout the world have been arranged in a regular succession of classes1 rising step by step from earliest ages up to the present time4 ,illustration ,,america ,,the ,,old ,,world 7,,from ,,geological ,,sketches47 ,,by ,l4 ,,agassiz4 ,illustration ,first-born among the ,continents1 though so much later in culture and civilization than some of more recent birth1 ,america1 so far as her physical history is concerned1 has been falsely denominated the ,new ,world4 ,hers was the first dry land lifted out of the waters1 hers the first shore washed by the ocean that enveloped all the earth beside2 and while ,europe was represented only by islands rising here and there above the sea1 ,america already stretched an unbroken line of land from ,nova ,scotia to the ,far ,west4 ,in the present state of our knowledge1 our conclusions respecting the beginning of the earth's history1 the way in which it took form and shape as a distinct1 separate planet1 must1 of course1 be very vague and hypothetical4 ,yet the progress of science is so rapidly reconstructing the past that we may hope to solve even this problem2 and to one who looks upon man's appearance upon the earth as the crowning work in a succession of creative acts1 all of which have had relation to his coming in the end1 it will not seem strange that he should at last be allowed to understand a history which was but the introduction to his own existence4 ,it is my belief that not only the future1 but the past also1 is the inheritance of man1 and that we shall yet conquer our lost birthright4 ,even now our knowledge carries us far enough to warrant the assertion that there was a time when our earth was in a state of igneous fusion1 when no ocean bathed it and no atmosphere surrounded it1 when no wind blew over it and no rain fell upon it1 but an intense heat held all its materials in solution4 ,in those days the rocks which are now the very bones and sinews of our mother ,earth--her granites1 her porphyries1 her basalts1 her syenites--were melted into a liquid mass4 ,as ,i am writing for the unscientific reader1 who may not be familiar with the facts through which these inferences have been reached1 ,i will answer here a question which1 were we talking together1 he might naturally ask in a somewhat sceptical tone4 ,how do you know that this state of things ever existed1 and1 supposing that the solid materials of which our earth consists were ever in a liquid condition1 what right have you to infer that this condition was caused by the action of heat upon them8 ,i answer1 ,because it is acting upon them still2 because the earth we tread is but a thin crust floating on a liquid sea of molten materials2 because the agencies that were at work then are at work now1 and the present is the logical sequence of the past4 ,from artesian wells1 from mines1 from geysers1 from hot springs1 a mass of facts has been collected1 proving incontestably the heated condition of all substances at a certain depth below the earth's surface2 and if we need more positive evidence1 we have it in the fiery eruptions that even now bear fearful testimony to the molten ocean seething within the globe and forcing its way but from time to time4 ,the modern progress of ,geology has led us by successive and perfectly connected steps back to a time when what is now only an occasional and rare phenomenon was the normal condition of our earth2 when the internal fires were enclosed by an envelope so thin that it opposed but little resistance to their frequent outbreak1 and they constantly forced themselves through this crust1 pouring out melted materials that subsequently cooled and consolidated on its surface4 ,so constant were these eruptions1 and so slight was the resistance they encountered1 that some portions of the earlier rock-deposits are perforated with numerous chimneys1 narrow tunnels as it were1 bored by the liquid masses that poured out through them and greatly modified their first condition4 ,illustration3 ,,ideal ,,section ,,of ,a ,,volcano ,,in ,,action4 ,the question at once suggests itself1 ,how was even this thin crust formed8 what should cause any solid envelope1 however slight and filmy when compared to the whole bulk of the globe1 to form upon the surface of such a liquid mass8 ,at this point of the investigation the geologist must appeal to the astronomer2 for in this vague and nebulous border-land1 where the very rocks lose their outlines and flow into each other1 not yet specialized into definite forms and substances1--there the two sciences meet4 ,astronomy shows us our planet thrown off from the central mass of which it once formed a part1 to move henceforth in an independent orbit of its own4 ,that orbit1 it tells us1 passed through celestial spaces cold enough to chill this heated globe1 and of course to consolidate it externally4 ,we know1 from the action of similar causes on a smaller scale and on comparatively insignificant objects immediately about us1 what must have been the effect of this cooling process upon the heated mass of the globe4 ,all substances when heated occupy more space than they do when cold4 ,water1 which expands when freezing1 is the only exception to this rule4 ,the first effect of cooling the surface of our planet must have been to solidify it1 and thus to form a film or crust over it4 ,that crust would shrink as the cooling process went on2 in consequence of the shrinking1 wrinkles and folds would arise upon it1 and here and there1 where the tension was too great1 cracks and fissures would be produced4 ,in proportion as the surface cooled1 the masses within would be affected by the change of temperature outside of them1 and would consolidate internally also1 the crust gradually thickening by this process4 ,illustration3 ,a ,,volcano4 ,but there was another element without the globe1 equally powerful in building it up4 ,fire and water wrought together in this work1 if not always harmoniously1 at least with equal force and persistency4 ,i have said that there was a time when no atmosphere surrounded the earth2 but one of the first results of the cooling of its crust must have been the formation of an atmosphere1 with all the phenomena connected with it1--the rising of vapors1 their condensation into clouds1 the falling of rains1 the gathering of waters upon its surface4 ,water is a very active agent of destruction1 but it works over again the materials it pulls down or wears away1 and builds them up anew in other forms4 ,as soon as an ocean washed over the consolidated crust of the globe1 it would begin to abrade the surfaces upon which it moved1 gradually loosening and detaching materials1 to deposit them again as sand or mud or pebbles at its bottom in successive layers1 one above another4 ,thus1 in analyzing the crust of the globe1 we find at once two kinds of rocks1 the respective work of fire and water3 the first poured out from the furnaces within1 and cooling1 as one may see any mass of metal cool that is poured out from a smelting-furnace to-day1 in solid crystalline masses1 without any division into separate layers or leaves2 and the latter in successive beds1 one over another1 the heavier materials below1 the lighter above1 or sometimes in alternate layers1 as special causes may have determined successive deposits of lighter or heavier materials at some given spot4 ,there were many well-fought battles between geologists before it was understood that these two elements had been equally active in building up the crust of the earth4 ,the ground was hotly contested by the disciples of the two geological schools1 one of which held that the solid envelope of the earth was exclusively due to the influence of fire1 while the other insisted that it had been accumulated wholly under the agency of water4 ,this difference of opinion grew up very naturally2 for the great leaders of the two schools lived in different localities1 and pursued their investigations over regions where the geological phenomena were of an entirely opposite character1--the one exhibiting the effect of volcanic eruptions1 the other that of stratified deposits4 ,it was the old story of the two knights on opposite sides of the shield1 one swearing that it was made of gold1 the other that it was made of silver2 and almost killing each other before they discovered that it was made of both4 ,so prone are men to hug their theories and shut their eyes to any antagonistic facts1 that it is related of ,werner1 the great leader of the ,aqueous school1 that he was actually on his way to see a geological locality of especial interest1 but1 being told that it confirmed the views of his opponents1 he turned round and went home again1 refusing to see what might force him to change his opinions4 ,if the rocks did not confirm his theory1 so much the worse for the rocks1--he would none of them4 ,at last it was found that the two great chemists1 fire and water1 had worked together in the vast laboratory of the globe1 and since then scientific men have decided to work together also2 and if they still have a passage at arms occasionally over some doubtful point1 yet the results of their investigations are ever drawing them nearer to each other1--since men who study truth1 when they reach their goal1 must always meet at last on common ground4 ,the rocks formed under the influence of heat are called1 in geological language1 the ,igneous1 or1 as some naturalists have named them1 the ,plutonic rocks1 alluding to their fiery origin1 while the others have been called ,aqueous or ,neptunic rocks1 in reference to their origin under the agency of water4 ,a simpler term1 however1 quite as distinctive1 and more descriptive of their structure1 is that of the stratified and massive or unstratified rocks4 ,we shall see hereafter how the relative position of these two classes of rocks and their action upon each other enable us to determine the chronology of the earth1 to compare the age of her mountains1 and1 if we have no standard by which to estimate the positive duration of her continents1 to say at least which was the first-born among them1 and how their characteristic features have been successfully worked out4 ,i am aware that many of these inferences1 drawn from what is called the geological record1 must seem to be the work of the imagination4 ,in a certain sense this is true1--for imagination1 chastened by correct observation1 is our best guide in the study of ,nature4 ,we are too apt to associate the exercise of this faculty with works of fiction1 while it is in fact the keenest detective of truth4 ,illustration3 ,,dikes4 ,besides the stratified and massive rocks1 there is still a third set1 produced by the contact of these two1 and called1 in consequence of the changes thus brought about1 the ,metamorphic rocks4 ,the effect of heat upon clay is to bake it into slate2 limestone under the influence of heat becomes quick-lime1 or1 if subjected afterwards to the action of water1 it is changed to mortar2 sand under the same agency is changed to a coarse kind of glass4 ,suppose1 then1 that a volcanic eruption takes place in a region of the earth's surface where successive layers of limestone1 of clay1 and of sandstone1 have been previously deposited by the action of water4 ,if such an eruption has force enough to break through these beds1 the hot1 melted masses will pour out through the rent1 flow over its edges1 and fill all the lesser cracks and fissures produced by such a disturbance4 ,what will be the effect upon the stratified rocks8 ,wherever these liquid masses1 melted by a heat more intense than can be produced by any artificial means1 have flowed over them or cooled in immediate contact with them1 the clays will be changed to slate1 the limestone will have assumed a character more like marble1 while the sandstone will be vitrified4 ,this is exactly what has been found to be the case1 wherever the stratified rocks have been penetrated by the melted masses from beneath4 ,they have been themselves partially melted by the contact1 and when they have cooled again1 their stratification1 though still perceptible1 has been partly obliterated1 and their substance changed4 ,such effects may often be traced in dikes1 which are only the cracks in rocks filled by materials poured into them at some period of eruption when the melted masses within the earth were thrown out and flowed like water into any inequality or depression of the surface around4 ,the walls enclosing such a dike are often found to be completely altered by contact with its burning contents1 and to have assumed a character quite different from the rocks of which they make a part2 while the mass itself which fills the fissure shows by the character of its crystallization that it has cooled more quickly on the outside1 where it meets the walls1 than at the centre4 ,the first two great classes of rocks1 the unstratified and stratified rocks1 represent different epochs in the world's physical history3 the former mark its revolutions1 while the latter chronicle its periods of rest4 ,all mountains and mountain-chains have been upheaved by great convulsions of the globe1 which rent asunder the surface of the earth1 destroyed the animals and plants living upon it at the time1 and were then succeeded by long intervals of repose1 when all things returned to their accustomed order1 ocean and river deposited fresh beds in uninterrupted succession1 the accumulation of materials went on as before1 a new set of animals and plants were introduced1 and a time of building up and renewing followed the time of destruction4 ,these periods of revolution are naturally more difficult to decipher than the periods of rest2 for they have so torn and shattered the beds they uplifted1 disturbing them from their natural relations to each other1 that it is not easy to reconstruct the parts and give them coherence and completeness again4 ,but within the last half-century this work has been accomplished in many parts of the world with an amazing degree of accuracy1 considering the disconnected character of the phenomena to be studied2 and ,i think ,i shall be able to convince my readers that the modern results of geological investigation are perfectly sound logical inferences from well-established facts4 ,in this1 as in so many other things1 we are but children of a larger growth4 ,the world is the geologist's great puzzle-box2 he stands before it like the child to whom the separate pieces of his puzzle remain a mystery till he detects their relation and sees where they fit1 and then his fragments grow at once into a connected picture beneath his hand4444 ,when geologists first turned their attention to the physical history of the earth1 they saw at once certain great features which they took to be the skeleton and basis of the whole structure4 ,they saw the great masses of granite forming the mountains and mountain-chains1 with the stratified rocks resting against their slopes2 and they assumed that granite was the first primary agent1 and that all stratified rocks must be of a later formation4 ,although this involved a partial error1 as we shall see hereafter when we trace the upheavals of granite even into comparatively modern periods1 yet it held an important geological truth also2 for1 though granite formations are by no means limited to those early periods1 they are nevertheless very characteristic of them1 and are indeed the foundation-stones on which the physical history of the globe is built4 ,starting from this landmark1 the earlier geologists divided the world's history into three periods4 ,as the historian recognizes ,ancient ,history1 the ,middle ,ages1 and ,modern ,history as distinct phases in the growth of the human race1 so they distinguished between what they called the ,primary period1 when1 as they believed1 no life stirred on the surface of the earth2 the ,secondary or middle period1 when animals and plants were introduced1 and the land began to assume continental proportions2 and the ,tertiary period1 or comparatively modern geological times1 when the physical features of the earth as well as its inhabitants were approaching more nearly to the present condition of things4 ,but as their investigations proceeded1 they found that every one of these great ages of the world's history was divided into numerous lesser epochs1 each of which had been characterized by a peculiar set of animals and plants1 and had been closed by some great physical convulsion1 disturbing and displacing the materials accumulated during such a period of rest4 ,the further study of these subordinate periods showed that what had been called ,primary formations1 namely1 the volcanic or ,plutonic rocks formerly believed to be confined to the first geological ages1 belonged to all the periods1 successive eruptions having taken place at all times1 pouring up through the accumulated deposits1 penetrating and injecting their cracks1 fissures1 and inequalities1 as well as throwing out large masses on the surface4 ,up to our own day there has never been a period when such eruptions have not taken place1 though they have been constantly diminishing in frequency and extent4 ,in consequence of this discovery1 that rocks of igneous character were by no means exclusively characteristic of the earliest times1 they are now classified together upon very different grounds from those on which geologists first united them2 though1 as the name ,primary was long retained1 we still find it applied to them1 even in geological works of quite recent date4 ,this defect of nomenclature is to be regretted1 as likely to mislead the student1 because it seems to refer to time2 whereas it no longer signifies the age of the rocks1 but simply their character4 ,the name ,plutonic or ,massive rocks is1 however1 now almost universally substituted for that of ,primary4 ,a wide field of investigation still remains to be explored by the chemist and the geologist together1 in the mineralogical character of the ,plutonic rocks1 which differs greatly in the different periods4 ,the earlier eruptions seem to have been chiefly granitic1 though this must not be understood in too wide a sense1 since there are granite formations even as late as the ,tertiary period2 those of the middle periods were mostly porphyries and basalts2 while in the more recent ones1 lavas predominate4 ,we have as yet no clew to the laws by which this distribution of volcanic elements in the formation of the earth is regulated2 but there is found to be a difference in the crystals of the ,plutonic rocks belonging to different ages1 which1 when fully understood may enable us to determine the age of any ,plutonic rock by its mode of crystallization2 so that the mineralogist will as readily tell you by its crystals whether a bit of stone of igneous origin belongs to this or that period of the world's history1 as the palontologist will tell you by its fossils whether a piece of rock of aqueous origin belongs to the ,silurian or ,devonian or ,carboniferous deposits4 ,although subsequent investigations have multiplied so extensively not only the number of geological periods1 but also the successive creations that have characterized them1 yet the first general division into three great eras was nevertheless founded upon a broad and true generalization4 ,in the first stratified rocks in which any organic remains are found1 the highest animals are fishes1 and the highest plants are cryptogams2 in the middle periods reptiles come in1 accompanied by fern and moss forests2 in later times quadrupeds are introduced1 with a dicotyledonous vegetation4 ,so closely does the march of animal and vegetable life keep pace with the material progress of the world1 that we may well consider these three divisions1 included under the first general classification of its physical history1 as the three ,ages of ,nature2 the more important epochs which subdivide them may be compared to so many great dynasties1 while the lesser periods are the separate reigns contained therein4 ,of such epochs there are ten1 well known to geologists2 of the lesser periods about sixty are already distinguished1 while many more loom up from the dim regions of the past1 just discerned by the eye of science1 though their history is not yet unravelled4 ,before proceeding further1 ,i will enumerate the geological epochs in their succession1 confining myself1 however1 to such as are perfectly well established1 without alluding to those of which the limits are less definitely determined1 and which are still subject to doubts and discussions among geologists4 ,as ,i do not propose to make here any treatise of ,geology1 but simply to place before my readers some pictures of the old world1 with the animals and plants that have inhabited it at various times1 ,i shall avoid1 as far as possible1 all debatable ground1 and confine myself to those parts of my subject which are best known1 and can therefore be more clearly presented4 ,illustration3 ,,fossil ,,scorpion4--,,silurian ,,period4 ,first1 we have the ,azoic period1 devoid of life1 as its name signifies1--namely1 the earliest stratified deposits upon the heated film forming the first solid surface of the earth1 in which no trace of living thing has ever been found4 ,next comes the ,silurian period1 when the crust of the earth had thickened and cooled sufficiently to render the existence of animals and plants upon it possible1 and when the atmospheric conditions necessary to their maintenance were already established4 ,many of the names given to these periods are by no means significant of their character1 but are merely the result of accident3 as1 for instance1 that of ,silurian1 given by ,sir ,roderick ,murchison to this set of beds1 because he first studied them in that part of ,wales occupied by the ancient tribe of the ,silures4 ,the next period1 the ,devonian1 was for a similar reason named after the country of ,devonshire in ,england1 where it was first investigated4 ,upon this follows the ,carboniferous period1 with the immense deposits of coal from which it derives its name4 ,then comes the ,permian period1 named1 again1 from local circumstances1 the first investigation of its deposits having taken place in the province of ,permia in ,russia4 ,next in succession we have the ,triassic period1 so called from the trio of rocks1 the red sandstone1 ,muschel ,kalk 7shell-limestone71 and ,keuper 7clay71 most frequently combined in its formations2 the ,jurassic1 so amply illustrated in the chain of the ,jura1 where geologists first found the clew to its history2 and the ,cretaceous period1 to which the chalk cliffs of ,england and all the extensive chalk deposits belong4 ,upon these follow the so-called ,tertiary formations1 divided into three periods1 all of which have received most characteristic names in this epoch of the world's history we see the first approach to a condition of things resembling that now prevailing1 and ,sir ,charles ,lyell has most fitly named its three divisions1 the ,eocene1 ,miocene1 and ,pliocene4 ,the termination of the three words is made from the ,greek word ,kainos1 recent2 while ,eos signifies dawn1 ,meion less1 and ,pleion more4 ,thus ,eocene indicates the dawn of recent species1 ,pliocene their increase1 while ,miocene1 the intermediate term1 means less recent4 ,above these deposits comes what has been called in science the present period1--the modern times of the geologist1--that period to which man himself belongs1 and since the beginning of which1 though its duration be counted by hundreds of thousands of years1 there has been no alteration in the general configuration of the earth1 consequently no important modification of its climatic conditions1 and no change in the animals and plants inhabiting it4 ,illustration3 ,,crustacea4--,,devonian ,,period4 ,illustration3 ,,fish ,,of ,,the ,,devonian ,,period4 ,illustration3 ,,fish ,,of ,,the ,,carboniferous ,,period4 ,illustration3 ,,fossil ,,vegetation ,,of ,,carboniferous ,,period4 ,illustration3 ,,fish ,,of ,,the ,,permian ,,period4 ,i have spoken of the first of these periods1 the ,azoic1 as having been absolutely devoid of life1 and ,i believe this statement to be strictly true2 but ,i ought to add that there is a difference of opinion among geologists upon this point1 many believing that the first surface of our globe may have been inhabited by living beings1 but that all traces of their existence have been obliterated by the eruptions of melted materials1 which not only altered the character of those earliest stratified rocks1 but destroyed all the organic remains contained in them4 ,it will be my object to show1 not only that the absence of the climatic and atmospheric conditions essential to organic life1 as we understand it1 must have rendered the previous existence of any living beings impossible1 but also that the completeness of the ,animal ,kingdom in those deposits where we first find organic remains1 its intelligible and coherent connections with the successive creations of all geological times and with the animals now living1 afford the strongest internal evidence that we have indeed found in the lower ,silurian formations1 immediately following the ,azoic1 the beginning of life upon earth4 ,when a story seems to us complete and consistent from the beginning to the end1 we shall not seek for a first chapter1 even though the copy in which we have read it be so torn and defaced as to suggest the idea that some portion of it may have been lost4 ,the unity of the work1 as a whole1 is an incontestable proof that we possess it in its original integrity4 ,the validity of this argument will be recognized1 perhaps1 only by those naturalists to whom the ,animal ,kingdom has begun to appear as a connected whole4 ,for those who do not see order in ,nature it can have no value4 ,illustration3 ,,fossils ,,of ,,triassic ,,vegetation4 ,illustration3 ,,bird ,,of ,,the ,,jurassic ,,period47,the ,oldest ,bird47 ,illustration3 ,,skeleton ,,of ,,bird ,,of ,,the ,,cretaceous ,,period4 ,illustration3 ,,skeleton ,,of ,,animal ,,of ,,the ,,eocene ,,period4 ,for a table containing the geological periods in their succession1 ,i would refer to any modern text-book of ,geology1 or to an article in the ,atlantic ,monthly for ,march1 #ahfb1 upon ,methods of ,study in ,natural ,history1 where they are given in connection with the order of introduction of animals upon earth4 ,were these sets of rocks found always in the regular sequence in which ,i have enumerated them1 their relative age would be easily determined1 for their superposition would tell the whole story3 the lowest would1 of course1 be the oldest1 and we might follow without difficulty the ascending series1 till we reached the youngest and uppermost deposits4 ,but their succession has been broken up by frequent and violent alterations in the configuration of the globe4 ,land and water have changed their level1--islands have been transformed to continents1--sea-bottoms have become dry land1 and dry land has sunk to form sea-bottoms1--,alps and ,himalayas1 ,pyrenees and ,apennines1 ,alleghanies and ,rocky ,mountains1 have had their stormy birthdays since many of these beds have been piled one above another1 and there are but few spots on the earth's surface where any number of them may be found in their original order and natural position4 ,when we remember that ,europe1 which lies before us on the map as a continent1 was once an archipelago of islands1--that1 where the ,pyrenees raise their rocky barrier between ,france and ,spain1 the waters of the ,mediterranean and ,atlantic met1--that1 where the ,british ,channel flows1 dry land united ,england and ,france1 and ,nature in those days made one country of the lands parted since by enmities deeper than the waters that run between1--when we remember1 in short1 all the fearful convulsions that have torn asunder the surface of the earth1 as if her rocky record had indeed been written on paper1 we shall find a new evidence of the intellectual unity which holds together the whole physical history of the globe in the fact that through all the storms of time the investigator is able to trace one unbroken thread of thought from the beginning to the present hour4 ,illustration3 ,,skeleton ,,of ,,animal ,,of ,,the ,,miocene ,,period4 ,illustration3 ,,skeleton ,,of ,,animal ,,of ,,the ,,pliocene ,,period4 ,the tree is known by its fruits1--and the fruits of chance are incoherence1 incompleteness1 unsteadiness1 the stammering utterance of blind1 unreasoning force4 ,a coherence that binds all the geological ages in one chain1 a stability of purpose that completes in the beings born to-day an intention expressed in the first creatures that swam in the ,silurian ocean or crept upon its shores1 a steadfastness of thought1 practically recognized by man1 if not acknowledged by him1 whenever he traces the intelligent connection between the facts of ,nature and combines them into what he is pleased to call his system of ,geology1 or ,zology1 or ,botany1--these things are not the fruits of chance or of an unreasoning force1 but the legitimate results of intellectual power4 ,there is a singular lack of logic1 as it seems to me1 in the views of the materialistic naturalists4 ,while they consider classification1 or1 in other words1 their expression of the relations between animals or between physical facts of any kind1 as the work of their intelligence1 they believe the relations themselves to be the work of physical causes4 ,the more direct inference surely is1 that1 if it requires an intelligent mind to recognize them1 it must have required an intelligent mind to establish them4 ,these relations existed before man was created2 they have existed ever since the beginning of time2 hence1 what we call the classification of facts is not the work of his mind in any direct original sense1 but the recognition of an intelligent action prior to his own existence4 ,there is1 perhaps1 no part of the world1 certainly none familiar to science1 where the early geological periods can be studied with so much ease and precision as in the ,united ,states4 ,along their northern borders1 between ,canada and the ,united ,states1 there runs the low line of hills known as the ,laurentian ,hills4 ,insignificant in height1 nowhere rising more than fifteen hundred or two thousand feet above the level of the sea1 these are nevertheless the first mountains that broke the uniform level of the earth's surface and lifted themselves above the waters4 ,their low stature1 as compared with that of other more lofty mountain-ranges1 is in accordance with an invariable rule1 by which the relative age of mountains may be estimated4 ,the oldest mountains are the lowest1 while the younger and more recent ones tower above their elders1 and are usually more torn and dislocated also4 ,this is easily understood1 when we remember that all mountains and mountain-chains are the result of upheavals1 and that the violence of the outbreak must have been in proportion to the strength of the resistance4 ,when the crust of the earth was so thin that the heated masses within easily broke through it1 they were not thrown to so great a height1 and formed comparatively low elevations1 such as the ,canadian hills or the mountains of ,bretagne and ,wales4 ,but in later times1 when young1 vigorous giants1 such as the ,alps1 the ,himalayas1 or1 later still1 the ,rocky ,mountains1 forced their way out from their fiery prison-house1 the crust of the earth was much thicker1 and fearful indeed must have been the convulsions which attended their exit4 ,illustration3 ,a ,,physical ,,map ,,of ,,the ,,united ,,states4 ,the ,laurentian ,hills form1 then1 a granite range1 stretching from ,eastern ,canada to the ,upper ,mississippi1 and immediately along its base are gathered the ,azoic deposits1 the first stratified beds1 in which the absence of life need not surprise us1 since they were formed beneath a heated ocean4 ,as well might we expect to find the remains of fish or shells or crabs at the bottom of geysers or of boiling springs1 as on those early shores bathed by an ocean of which the heat must have been so intense4 ,although1 from the condition in which we find it1 this first granite range has evidently never been disturbed by any violent convulsion since its first upheaval1 yet there has been a gradual rising of that part of the continent2 for the ,azoic beds do not lie horizontally along the base of the ,laurentian ,hills in the position in which they must originally have been deposited1 but are lifted and rest against their slopes4 ,they have been more or less dislocated in this process1 and are greatly metamorphized by the intense heat to which they must have been exposed4 ,indeed1 all the oldest stratified rocks have been baked by the prolonged action of heat4 ,it may be asked how the materials for those first stratified deposits were provided4 ,in later times1 when an abundant and various soil covered the earth1 when every river brought down to the ocean1 not only its yearly tribute of mud or clay or lime1 but the dbris of animals and plants that lived and died in its waters or along its banks1 when every lake and pond deposited at its bottom in successive layers the lighter or heavier materials floating in its waters and settling gradually beneath them1 the process by which stratified materials are collected and gradually harden into rock is more easily understood4 ,but when the solid surface of the earth was only just beginning to form1 it would seem that the floating matter in the sea can hardly have been in sufficient quantity to form any extensive deposits4 ,no doubt there was some abrasion even of that first crust2 but the more abundant source of the earliest stratification is to be found in the submarine volcanoes that poured their liquid streams into the first ocean4 ,at what rate these materials would be distributed and precipitated in regular strata it is impossible to determine2 but that volcanic materials were so deposited in layers is evident from the relative position of the earliest rocks4 ,i have already spoken of the innumerable chimneys perforating the ,azoic beds1 narrow outlets of ,plutonic rock1 protruding through the earliest strata4 ,not only are such funnels filled with the crystalline mass of granite that flowed through them in a liquid state1 but it has often poured over their sides1 mingling with the stratified beds around4 ,in the present state of our knowledge1 we can explain such appearances only by supposing that the heated materials within the earth's crust poured out frequently1 meeting little resistance1--that they then scattered and were precipitated in the ocean around1 settling in successive strata at its bottom1--that through such strata the heated masses within continued to pour again and again1 forming for themselves the chimney-like outlets above mentioned4 ,such1 then1 was the earliest ,american land1--a long1 narrow island1 almost continental in its proportions1 since it stretched from the eastern borders of ,canada nearly to the point where now the base of the ,rocky ,mountains meets the plain of the ,mississippi ,valley4 ,we may still walk along its ridge and know that we tread upon the ancient granite that first divided the waters into a northern and southern ocean2 and if our imaginations will carry us so far1 we may look down toward its base and fancy how the sea washed against this earliest shore of a lifeless world4 ,this is no romance1 but the bald1 simple truth2 for the fact that this granite band was lifted out of the waters so early in the history of the world1 and has not since been submerged1 has1 of course1 prevented any subsequent deposits from forming above it4 ,and this is true of all the northern part of the ,united ,states4 ,it has been lifted gradually1 the beds deposited in one period being subsequently raised1 and forming a shore along which those of the succeeding one collected1 so that we have their whole sequence before us4 ,in regions where all the geological deposits 7,silurian1 ,devonian1 carboniferous1 permian1 triassic1 etc47 are piled one upon another1 and we can get a glimpse of their internal relations only where some rent has laid them open1 or where their ragged edges1 worn away by the abrading action of external influences1 expose to view their successive layers1 it must1 of course1 be more difficult to follow their connection4 ,for this reason the ,american continent offers facilities to the geologist denied to him in the so-called ,old ,world1 where the earlier deposits are comparatively hidden1 and the broken character of the land1 intersected by mountains in every direction1 renders his investigation still more difficult4 ,of course1 when ,i speak of the geological deposits as so completely unveiled to us here1 ,i do not forget the sheet of drift which covers the continent from north to south1 and which we shall discuss hereafter1 when ,i reach that part of my subject4 ,but the drift is only a superficial and recent addition to the soil1 resting loosely above the other geological deposits1 and arising1 as we shall see1 from very different causes4 ,in this article ,i have intended to limit myself to a general sketch of the formation of the ,laurentian ,hills with the ,azoic stratified beds resting against them4 ,in the ,silurian epoch following the ,azoic we have the first beach on which any life stirred2 it extended along the base of the ,azoic beds1 widening by its extensive deposits the narrow strip of land already upheaved4 ,i propose 444 to invite my readers to a stroll with me along that beach4 ,with what interest do we look upon any relic of early human history6 ,the monument that tells of a civilization whose hieroglyphic records we cannot even decipher1 the slightest trace of a nation that vanished and left no sign of its life except the rough tools and utensils buried in the old site of its towns or villages1 arouses our imagination and excites our curiosity4 ,men gaze with awe at the inscription on an ancient ,egyptian or ,assyrian stone2 they hold with reverential touch the yellow parchment-roll whose dim1 defaced characters record the meagre learning of a buried nationality2 and the announcement1 that for centuries the tropical forests of ,central ,america have hidden within their tangled growth the ruined homes and temples of a past race1 stirs the civilized world with a strange1 deep wonder4 ,to me it seems1 that to look on the first land that was ever lifted above the waste of waters1 to follow the shore where the earliest animals and plants were created when the thought of ,god first expressed itself in organic forms1 to hold in one's hand a bit of stone from an old sea-beach1 hardened into rock thousands of centuries ago1 and studded with the beings that once crept upon its surface or were stranded there by some retreating wave1 is even of deeper interest to men than the relies of their own race1 for these things tell more directly of the thoughts and creative acts of ,god4 ,standing in the neighborhood of ,whitehall1 near ,lake ,george1 one may look along such a seashore1 and see it stretching westward and sloping gently southward as far as the eye can reach4 ,it must have had a very gradual slope1 and the waters must have been very shallow2 for at that time no great mountains had been uplifted1 and deep oceans are always the concomitants of lofty heights4 ,we do not1 however1 judge of this by inference merely2 we have an evidence of the shallowness of the sea in those days in the character of the shells found in the ,silurian deposits1 which shows that they belonged in shoal waters4 ,indeed1 the fossil remains of all times tell us almost as much of the physical condition of the world at different epochs as they do of its animal and vegetable population4 ,when ,robinson ,crusoe first caught sight of the footprint on the sand1 he saw in it more than the mere footprint1 for it spoke to him of the presence of men on his desert island4 ,we walk on the old geological shores1 like ,crusoe along his beach1 and the footprints we find there tell us1 too1 more than we actually see in them4 ,the crust of our earth is a great cemetery1 where the rocks are tombstones on which the buried dead have written their own epitaphs4 ,they tell us not only who they were and when and where they lived1 but much also of the circumstances under which they lived4 ,we ascertain the prevalence of certain physical conditions at special epochs by the presence of animals and plants whose existence and maintenance required such a state of things1 more than by any positive knowledge respecting it4 ,where we find the remains of quadrupeds corresponding to our ruminating animals1 we infer not only land1 but grassy meadows also1 and an extensive vegetation2 where we find none but marine animals1 we know the ocean must have covered the earth2 the remains of large reptiles1 representing1 though in gigantic size1 the half aquatic1 half terrestrial reptiles of our own period1 indicate to us the existence of spreading marshes still soaked by the retreating waters2 while the traces of such animals as live now in sand and shoal waters1 or in mud1 speak to us of shelving sandy beaches and of mud-flats4 ,the eye of the ,trilobite tells us that the sun shone on the old beach where he lived2 for there is nothing in nature without a purpose1 and when so complicated an organ was made to receive the light1 there must have been light to enter it4 ,the immense vegetable deposits in the ,carboniferous period announce the introduction of an extensive terrestrial vegetation2 and the impressions left by the wood and leaves of the trees show that these first forests must have grown in a damp soil and a moist atmosphere4 ,in short1 all the remains of animals and plants hidden in the rocks have something to tell of the climatic conditions and the general circumstances under which they lived1 and the study of fossils is to the naturalist a thermometer by which he reads the variations of temperature in past times1 a plummet by which he sounds the depths of the ancient oceans1--a register1 in fact1 of all the important physical changes the earth has undergone4 ,but although the animals of the early geological deposits indicate shallow seas by their similarity to our shoal-water animals1 it must not be supposed that they are by any means the same4 ,on the contrary1 the old shells1 crustacea1 corals1 etc41 represent types which have existed in all times with the same essential structural elements1 but under different specific forms in the several geological periods4 ,and here it may not be amiss to say something of what are called by naturalists representative types4 ,the statement that different sets of animals and plants have characterized the successive epochs is often understood as indicating a difference of another kind than that which distinguishes animals now living in different parts of the world4 ,this is a mistake4 ,there are so-called representative types all over the globe1 united to each other by structural relations and separated by specific differences of the same kind as those that unite and separate animals of different geological periods4 ,take1 for instance1 mud-flats or sandy shores in the same latitudes of ,europe and ,america2 we find living on each1 animals of the same structural character and of the same general appearance1 but with certain specific differences1 as of color1 size1 external appendages1 etc4 ,they represent each other on the two continents4 ,the ,american wolves1 foxes1 bears1 rabbits1 are not the same as the ,european1 but those of one continent are as true to their respective types as those of the other2 under a somewhat different aspect they represent the same groups of animals4 ,in certain latitudes1 or under conditions of nearer proximity1 these differences may be less marked4 ,it is well known that there is a great monotony of type1 not only among animals and plants1 but in the human races also1 throughout the ,arctic regions2 and some animals characteristic of the high ,north reappear under such identical forms in the neighborhood of the snow-fields in lofty mountains1 that to trace the difference between the ptarmigans1 rabbits1 and other gnawing animals of the ,alps1 for instance1 and those of the ,arctics1 is among the most difficult problems of modern science4 ,and so it is also with the animated world of past ages2 in similar deposits of sand1 mud1 or lime1 in adjoining regions of the same geological age1 identical remains of animals and plants may be found2 while at greater distances1 but under similar circumstances1 representative species may occur4 ,in very remote regions1 however1 whether the circumstances be similar or dissimilar1 the general aspect of the organic world differs greatly1 remoteness in space being thus in some measure an indication of the degree of affinity between different faun4 ,in deposits of different geological periods immediately following each other1 we sometimes find remains of animals and plants so closely allied to those of earlier or later periods that at first sight the specific differences are hardly discernible4 ,the difficulty of solving these questions1 and of appreciating correctly the differences and similarities between such closely allied organisms1 explains the antagonistic views of many naturalists respecting the range of existence of animals1 during longer or shorter geological periods2 and the superficial way in which discussions concerning the transition of species are carried on1 is mainly owing to an ignorance of the conditions above alluded to4 ,my own personal observation and experience in these matters have led me to the conviction that every geological period has had its own representatives1 and that no single species has been repeated in successive ages4 ,the laws regulating the geographical distribution of animals1 and their combination into distinct zological provinces called faun1 with definite limits1 are very imperfectly understood as yet2 but so closely are all things linked together from the beginning that ,i am convinced we shall never find the clew to their meaning till we carry on our investigations in the past and the present simultaneously4 ,the same principle according to which animal and vegetable life is distributed over the surface of the earth now1 prevailed in the earliest geological periods4 ,the geological deposits of all times have had their characteristic faun under various zones1 their zological provinces presenting special combinations of animal and vegetable life over certain regions1 and their representative types reproducing in different countries1 but under similar latitudes1 the same groups with specific differences4 ,of course1 the nearer we approach the beginning of organic life1 the less marked do we find the differences to be1 and for a very obvious reason4 ,the inequalities of the earth's surface1 her mountain-barriers protecting whole continents from the ,arctic winds1 her open plains exposing others to the full force of the polar blasts1 her snug valleys and her lofty heights1 her tablelands and rolling prairies1 her river-systems and her dry deserts1 her cold ocean-currents pouring down from the high ,north on some of her shores1 while warm ones from tropical seas carry their softer influence to others1--in short1 all the contrasts in the external configuration of the globe1 with the physical conditions attendant upon them1 are naturally accompanied by a corresponding variety in animal and vegetable life4 ,but in the ,silurian age1 when there were no elevations higher than the ,canadian hills1 when water covered the face of the earth1 with the exception of a few isolated portions lifted above the almost universal ocean1 how monotonous must have been the conditions of life6 ,and what should we expect to find on those first shores8 ,if we are walking on a sea-beach to-day1 we do not look for animals that haunt the forests or roam over the open plains1 or for those that live in sheltered valleys or in inland regions or on mountain-heights4 ,we look for ,shells1 for ,mussels and ,barnacles1 for ,crabs1 for ,shrimps1 for ,marine ,worms1 for ,star-,fishes and ,sea-,urchins1 and we may find here and there a fish stranded on the sand or tangled in the seaweed4 ,illustration ,,some ,,records ,,of ,,the ,,rocks 7,,from ,a ,,first ,,book ,,in ,,geology47 ,,by ,n4,s4 ,,shaler1 ,s4,d4#a ,footnote #a3 ,copyright1 #ahhd1 by ,n4,s4 ,shaler4 ,illustration ,the geologist cannot find his way back in the record of the great stone book1 to the far-off day when life began4 ,the various changes that come over rocks from the action of heat1 of water1 and of pressure1 have slowly modified these ancient beds1 so that they no longer preserve the frames of the animals that were buried in them4 ,these old rocks1 which are so changed that we cannot any longer make sure that any animals lived in them1 are called the archan1 which is ,greek for ancient4 ,they were probably mud and sand and limestone when first made1 but they have been changed to mica schists1 gneiss1 granite1 marble1 and other crystalline rocks4 ,when any rock becomes crystalline1 the fossils dissolve and disappear1 as coins lose their stamp and form when they are melted in the jeweller's gold-pot4 ,these ancient rocks that lie deepest in the earth are very thick1 and must have taken a great time in building2 great continents must have been worn down by rain and waves in order to supply the waste out of which they were made4 ,it is tolerably certain that they took as much time during their making as has been required for all the other times since they were formed4 ,during the vast ages of this archan the life of our earth began to be4 ,we first find many certain evidences of life in the rocks which lie on top of the archan rock1 and are known as the ,cambriani and ,silurian periods4 ,there we have creatures akin to our corals and crabs and worms1 and others that are the distant kindred of the cuttle-fishes and of our lamp-shells4 ,there were no backboned animals1 that is to say1 no land mammals1 reptiles1 or fishes at this stage of the earth's history4 ,it is not likely that there was any land life except of plants and those forms like the lowest ferns1 and probably mosses4 ,nor is it likely that there were any large continents as at the present time1 but rather a host of islands lying where the great lands now are1 the budding tops of the continents just appearing above the sea4 ,although the life of this time was far simpler than at the present day1 it had about as great variety as we would find on our present sea-floors4 ,there were as many different species living at the same time on a given surface4 ,the ,cambrian and ,silurian time--the time before the coming of the fishes--must have endured for many million years without any great change in the world4 ,hosts of species lived and died2 half a dozen times or more the life of the earth was greatly changed4 ,new species came much like those that had gone before1 and only a little gain here and there was perceptible at any time4 ,still1 at the end of the ,silurian1 the life of the world had climbed some steps higher in structure and in intelligence4 ,illustration3 ,,fig4 #a4 ,,north ,,america ,,in ,,cambrian ,,time4 ,the next set of periods is known as the ,devonian4 ,it is marked by the rapid extension of the fishes2 for1 although the fishes began in the uppermost ,silurian1 they first became abundant in this time4 ,these1 the first strong-jawed tyrants of the sea1 came all at once1 like a rush of the old ,norman pirates into the peaceful seas of ,great ,britain4 ,they made a lively time among the sluggish beings of that olden sea4 ,creatures that were able to meet feebler enemies were swept away or compelled to undergo great changes1 and all the life of the oceans seems to have a spur given to it by these quicker-formed and quicker-willed animals4 ,in this ,devonian section of our rocks we have proofs that the lands were extensively covered with forests of low fern trees1 and we find the first trace of air-breathing animals in certain insects akin to our dragon-flies4 ,in this stage of the earth's history the fishes grew constantly more plentiful1 and the seas had a great abundance of corals and crinoids4 ,except for the fishes1 there were no very great changes in the character of the life from that which existed in the earlier time of the ,cambrian and ,silurian4 ,the animals are constantly changing1 but the general nature of the life remains the same as in the earlier time4 ,illustration3 ,,fig4 #b4 ,,raniceps ,,lyelli--,,coal ,,time ,,salamander4 ,in the ,carboniferous or coal-bearing age1 we have the second great change in the character of the life on the earth4 ,of the earlier times1 we have preserved only the rocks formed in the seas4 ,but rarely do we find any trace of the land life or even of the life that lived along the shores4 ,in this ,carboniferous time1 however1 we have very extensive sheets of rocks which were formed in swamps in the way shown in the earlier part of this book4 ,they constitute our coal-beds1 which1 though much worn away by rain and sea1 still cover a large part of the land surface4 ,these beds of coal grew in the air1 and1 although the swamps where they were formed had very little animal life in them1 we find some fossils which tell us that the life of the land was making great progress2 there are new insects1 including beetles1 cockroaches1 spiders1 and scorpions1 and1 what is far more important1 there are some air-breathing1 back-boned animals1 akin to the salamanders and water-dogs of the present day4 ,these were nearly as large as alligators1 and of much the same shape1 but they were probably born from the egg in the shape of tadpoles and lived for a time in the water as our young frogs1 toads1 and salamanders do4 ,this is the first step upwards from the fishes to land vertebrates2 and we may well be interested in it1 for it makes one most important advance in creatures through whose lives our own existence became possible4 ,still1 these ancient woods of the coal period must have had little of the life we now associate with the forests2 there were still no birds1 no serpents1 no true lizards1 no suck-giving animals1 no flowers1 and no fruits4 ,these coal-period forests were sombre wastes of shade1 with no sound save those of the wind1 the thunder1 and the volcano1 or of the running streams and the waves on the shores4 ,in the seas of the ,carboniferous time1 we notice that the ancient life of the earth is passing away4 ,many creatures1 such as the trilobites1 die out1 and many other forms such as the crinoids or sea lilies become fewer in kind and of less importance4 ,these marks of decay in the marine life continue into the beds just after the ,carboniferous1 known as the ,permian1 which are really the last stages of the coal-bearing period4 ,when with the changing time we pass to the beds known as the ,triassic1 which were made just after the close of the ,carboniferous time1 we find the earth undergoing swift changes in its life4 ,the moist climate and low lands that caused the swamps to grow so rapidly have ceased to be1 and in their place we appear to have warm1 dry air1 and higher lands4 ,on these lands of the ,triassic time the air-breathing life made very rapid advances4 ,the plants are seen to undergo considerable changes4 ,the ferns no longer make up all the forests1 but trees more like the pines began to abound1 and insects became more plentiful and more varied4 ,illustration3 ,,fig4 #c4 ,,cycas ,,circinalis1 ,,akin ,,to ,,highest ,,plants ,,of ,,coal ,,time4 ,hitherto the only land back-boned animal was akin to our salamanders4 ,now we have true lizards in abundance1 many of them of large size4 ,some of them were probably plant-eaters1 but most were flesh-eaters2 some seem to have been tenants of the early swamps1 and some dwelt in the forests4 ,the creatures related to the salamanders have increased in the variety of their forms to a wonderful extent4 ,we know them best by the tracks which they have left on the mud stones formed on the borders of lakes or the edge of the sea4 ,in some places these footprints are found in amazing numbers and perfection4 ,the best place for them is in the ,connecticut ,valley1 near ,turner's ,falls1 ,mass4 ,at this point the red sandstone and shale beds1 which are composed of thin layers having a total thickness of several hundred feet1 are often stamped over by these footprints like the mud of a barnyard4 ,from the little we can determine from these footprints1 the creatures seem to have been somewhat related to our frogs1 but they generally had tails1 and1 though provided with four legs1 were in the habit of walking on the hind ones alone like the kangaroo4 ,a few of these tracks are shown in the figure on this page4 ,illustration3 ,,fig4 #d4 ,,foot-,,prints1 ,,connecticut ,,sandstones4 ,these strange creatures were of many different species4 ,some of them must have been six or seven feet high1 for their steps are as much as three feet apart1 and seem to imply a creature weighing several hundred pounds4 ,others were not bigger than robins4 ,strangely enough1 we have never found their bones nor the creatures on which they fed1 and but for the formation of a little patch of rocks here and there we should not have had even these footprints to prove to us that such creatures had lived in the ,connecticut ,valley in this far-off time4 ,illustration3 ,,fig4 #e4 ,,foot-,,print1 ,,turner',s ,,falls4 ,but these wonderful forms are less interesting than two or three little fossil jaw-bones that prove to us that in this ,triassic time the earth now bore another animal more akin to ourselves1 in the shape of a little creature that gave suck to its young4 ,once more life takes a long upward step in this little opossum-like animal1 perhaps the first creature whose young was born alive4 ,these little creatures called ,microlestes or ,dromatherium1 of which only one or two different but related species have been found in ,england and in ,north ,carolina1 appear to have been insect-eaters of about the size and shape of the ,australian creature shown in ,fig4 #g4 ,so far we know it in but few specimens1--altogether only an ounce or two of bones1--but they are very precious monuments of the past4 ,illustration3 ,,fig4 #f4 ,,dromatherium ,,sylvestre ,,and ,,teeth ,,of ,,microlestes ,,antiquus4 ,in this ,triassic time the climate appears to have been rather dry1 for in it we have many extensive deposits of salt formed by the evaporation of closed lakes1 of seas1 such as are now forming on the bottom of the ,dead ,sea1 and the ,great ,salt ,lake of ,utah1 and a hundred or more other similar basins of the present day4 ,illustration3 ,,fig4 #g4 ,,myrmecobius4 ,in the sea animals of this time we find many changes4 ,already some of the giant lizard-like animals1 which first took shape on the land1 are becoming swimming-animals4 ,they changed their feet to paddles1 which1 with the help of a flattened tail1 force them through the water4 ,the fishes on which these great swimming lizards preyed are more like the fishes of our present day than they were before4 ,the trilobites are gone1 and of the crinoids only a remnant is left4 ,most of the corals of the earlier days have disappeared1 but the mollusks have not changed more than they did at several different times in the earliest stages of the earth's history4 ,illustration3 ,,fig4 #h4 ,,ichthyosaurus ,,and ,,plesiosaurus4 ,after the ,trias comes a long succession of ages in which the life of the world is steadily advancing to higher and higher planes2 but for a long time there is no such startling change as that which came in the passage from the coal series of rocks to the ,trias4 ,this long set of periods is known to geologists as the age of reptiles4 ,it is well named1 for the kindred of the lizards then had the control of the land4 ,there were then none of our large fish to dispute their control1 so they shaped themselves to suit all the occupations that could give them a chance for a living4 ,some remained beasts of prey like our alligators1 but grew to larger size2 some took to eating the plants1 and came to walk on their four legs as our ordinary beasts do1 no longer dragging themselves on their bellies as do the lizard and alligator1 their lower kindred4 ,others became flying creatures like our bats1 only vastly larger1 often with a spread of wing of fifteen or twenty feet4 ,yet others1 even as strangely shaped1 dwelt with the sharks in the sea4 ,illustration3 ,,fig4 #i4 ,,reptiles ,,of ,,jurassic ,,period4 ,in this time of the earth's history we have the first bird-like forms4 ,they were feathered creatures1 with bills carrying true teeth1 and with strong wings2 but they were reptiles in many features1 having long1 pointed tails such as none of our existing birds have4 ,they show us that the birds are the descendants of reptiles1 coming off from them as a branch does from the parent tree4 ,the tortoises began in this series of rocks4 ,at first they are marine or swimming forms1 the box-turtles coming later4 ,here too begin many of the higher insects4 ,creatures like moths and bees appear1 and the forests are enlivened with all the important kinds of insects1 though the species were very different from those now living4 ,in the age of reptiles the plants have made a considerable advance4 ,palms are plenty2 forms akin to our pines and firs abound1 and the old flowerless group of ferns begins to shrink in size1 and no longer spreads its feathery foliage over all the land as before4 ,still there were none of our common broad-leaved trees2 the world had not yet known the oaks1 birches1 maples1 or any of our hard-wood trees that lose their leaves in autumn2 nor were the flowering plants1 those with gay blossoms1 yet on the earth4 ,the woods and fields were doubtless fresh and green1 but they wanted the grace of blossoms1 plants1 and singing-birds4 ,none of the animals could have had the social qualities or the finer instincts that are so common among animals of the present day4 ,there were probably no social animals like our ants and bees1 no merry singing creatures2 probably no forms that went in herds4 ,life was a dull round of uncared-for birth1 cruel self-seeking1 and of death4 ,the animals at best were clumsy1 poorly-endowed creatures1 with hardly more intelligence than our alligators4 ,the little thread of higher life begun in the ,microlestes and ,dromatherium1 the little insect-eating mammals of the forest1 is visible all through this time4 ,it held in its warm blood the powers of the time to come1 but it was an insignificant thing among the mighty cold-blooded reptiles of these ancient lands4 ,there are several species of them1 but they are all small1 and have no chance to make headway against the older masters of the earth4 ,the ,jurassic or first part of the reptilian time shades insensibly into the second part1 called the ,cretaceous1 which immediately follows it4 ,during this period the lands were undergoing perpetual changes2 rather deep seas came to cover much of the land surfaces1 and there is some reason to believe that the climate of the earth became much colder than it had been1 at least in those regions where the great reptiles had flourished4 ,it may be that it is due to a colder climate that we owe the rapid passing away of this gigantic reptilian life of the previous age4 ,the reptiles1 being cold-blooded1 cannot stand even a moderate winter cold1 save when they are so small that they can crawl deep into crevices in the rocks to sleep the winter away1 guarded from the cold by the warmth of the earth4 ,at any rate these gigantic animals rapidly ceased to be1 so that by the middle of the ,cretaceous period they were almost all gone1 except those that inhabited the sea2 and at the end of this time they had shrunk to lizards in size4 ,the birds continue to increase and to become more like those of our day2 their tails shrink away1 their long bills lose their teeth2 they are mostly water-birds of large size1 and there are none of our songsters yet2 still they are for the first time perfect birds1 and no longer half-lizard in their nature4 ,the greatest change in the plants is found in the coming of the broad-leaved trees belonging to the families of our oaks1 maples1 etc4 ,now for the first time our woods take on their aspect of to-day2 pines and other cone-bearers mingle with the more varied foliage of nut-bearing or large-seeded trees4 ,curiously enough1 we lose sight of the little mammals of the earlier time4 ,this is probably because there is very little in the way of land animals of this period preserved to us4 ,there are hardly any mines or quarries in the beds of this age to bring these fossils to light4 ,in the most of the other rocks there is more to tempt man to explore them for coal ores or building stones4 ,in passing from the ,cretaceous to the ,tertiary1 we enter upon the threshold of our modern world4 ,we leave behind all the great wonders of the old world1 the gigantic reptiles1 the forests of tree ferns1 the seas full of ammonites and belemnites1 and come among the no less wonderful but more familiar modern forms4 ,we come at once into lands and seas where the back-boned animals are the ruling beings4 ,the reptiles have shrunk to a few low forms1--the small lizards1 the crocodiles and alligators1 the tortoises and turtles1 and1 as if to mark more clearly the banishment of this group from their old empire1 the serpents1 which are peculiarly degraded forms of reptiles which have lost the legs they once had1 came to be the commonest reptiles of the earth4 ,the first mammals that have no pouches now appear4 ,in earlier times1 the suck-giving animals all belonged to the group that contains our opossums1 kangaroos1 etc4 ,these creatures are much lower and feebler than the mammals that have no pouches4 ,although they have probably been on the earth two or three times as long as the higher mammals1 they have never attained any eminent success whatever2 they cannot endure cold climates2 none of them are fitted for swimming as are the seals and whales1 or for flying as the bats1 or for burrowing as the moles2 they are dull1 weak things1 which are not able to contend with their stronger1 better-organized1 higher kindred4 ,they seem not only weak1 but unable to fit themselves to many different kinds of existence4 ,in the lower part of the ,tertiary rocks1 we find at once a great variety of large beasts that gave suck to their young4 ,it is likely that these creatures had come into existence in a somewhat earlier time in other lands1 where we have not been able to study the fossils2 for to make their wonderful forms slowly1 as we believe them to have been made1 would require a very long time4 ,it is probable that during the ,cretaceous time1 in some land where we have not yet had a chance to study the rocks1 these creatures grew to their varied forms1 and that in the beginning of the ,tertiary time1 they spread into the regions where we find their bones4 ,beginning with the ,tertiary time1 we find these lower kinsmen of man1 through whom man came to be4 ,the mammals were marked by much greater simplicity and likeness to each other than they now have4 ,there were probably no monkeys1 no horses1 no bulls1 no sheep1 no goats1 no seals1 no whales1 and no bats4 ,all these animals had many-fingered feet4 ,there were no cloven feet like those of our bulls1 and no solid feet as our horses have4 ,their brains1 which by their size give us a general idea of the intelligence of the creature1 are small2 hence we conclude that these early mammals were less intelligent than those of our day4 ,it would require volumes to trace the history of the growth of these early mammals1 and show how they1 step by step1 came to their present higher state4 ,we will take only one of the simplest of these changes1 which happens to be also the one which we know best4 ,this is the change that led to the making of our common horses1 which seem to have been brought into life on the continent of ,north ,america4 ,the most singular thing about our horses is that the feet have but one large toe or finger1 the hoof1 the hard covering of which is the nail of that extremity4 ,now it seems hard to turn the weak1 five-fingered feet of the animals of the lower ,tertiary--feet which seem to be better fitted for tree-climbing than anything else--into feet such as we find in the horse4 ,yet the change is brought about by easy stages that lead the successive creatures from the weak and loose-jointed foot of the ancient forms to the solid1 single-fingered horse's hoof1 which is wonderfully well-fitted for carrying a large beast at a swift speed1 and is so strong a weapon of defence that an active donkey can kill a lion with a well-delivered kick4 ,illustration3 ,,fig4 #aj4 ,,feet ,,of ,,tertiary ,,mammals4 ,the oldest of these creatures that lead to the horses is called ,eohippus or beginning horse4 ,this fellow had on the forefeet four large toes1 each with a small hoof and fifth imperfect one1 which answered to the thumb4 ,the hind feet had gone further in the change1 for they each had but three toes1 each with hoofs1 the middle-toed hoof larger and longer than the others4 ,a little later toward our day we find another advance in the ,orohippus1 when the little imperfect thumb has disappeared1 and there are only four toes on the forefeet and three on the hind4 ,yet later we have the ,mesohippus or half-way horse4 ,there are still three toes on the hind foot1 but one more of the fingers of the forefeet has disappeared4 ,this time it is the little finger that goes1 leaving only a small bone to show that its going was by a slow shrinking4 ,the creature now has three little hoofs on each of its feet4 ,still nearer our own time comes the ,miohippus1 which shows the two side hoofs on each foot shrinking up so that they do not touch the ground1 but they still bear little hoofs4 ,lastly1 about the time of man's coming on the earth1 appears his faithful servant1 the horse1 in which those little side hoofs have disappeared1 leaving only two little splint bones to mark the place where these side hoofs belong4 ,thus1 step by step1 our horses' feet were built up2 while these parts were changing1 the other parts of the animals were also slowly altering4 ,they were at first smaller than our horses1--some of them not as large as an ordinary ,newfoundland dog2 others as small as foxes4 ,illustration3 ,,fig4 #aa4 ,,development ,,of ,,horses',s ,,foot4 ,as if to remind us of his old shape1 our horses now and then1 but rarely1 have1 in place of the little splint bones above the hoof1 two smaller hoofs1 just like the foot of ,miohippus4 ,sometimes these are about the size of a silver dollar1 on the part that receives the shoe when horses are shod4 ,in this way1 by slow-made changes1 the early mammals pass into the higher4 ,out of one original part are made limbs as different as the feet of the horse1 the wing of a bat1 the paddle of a whale1 and the hand of man4 ,so with all the parts of the body the forms change to meet the different uses to which they are put4 ,at the end of this long promise1 which was written in the very first animals1 comes man himself1 in form closely akin to the lower animals1 but in mind immeasurably apart from them4 ,we can find every part of man's body in a little different shape in the monkeys1 but his mind is of a very different quality4 ,while his lower kindred cannot be made to advance in intelligence any more than man himself can grow a horse's foot or a bat's wing1 he is constantly going higher and higher in his mental and moral growth4 ,so far we have found but few traces of man that lead us to suppose that he has been for a long geological time on the earth1 yet there is good evidence that he has been here for a hundred thousand years or more4 ,it seems pretty clear that he has changed little in his body in all these thousands of generations4 ,the earliest remains show us a large-brained creature1 who used tools and probably had already made a servant of fire1 which so admirably aids him in his work4 ,besides the development of this wonderful series of animals1 that we may call in a certain way our kindred1 there have been several other remarkable advances in this ,tertiary time1 this age of crowning wonders in the earth's history4 ,the birds have gone forward very rapidly2 it is likely that there were no songsters at the first part of this period1 but these singing birds have developed very rapidly in later times4 ,among the insects the most remarkable growth is among the ants1 the bees1 and their kindred4 ,these creatures have very wonderful habits2 they combine together for the making of what we may call states1 they care for their young1 they wage great battles1 they keep slaves1 they domesticate other insects1 and in many ways their acts resemble the doings of man4 ,coming at about the same time as man1 these intellectual insects help to mark this later stage of the earth as the intellectual period in its history4 ,now for the first time creatures are on the earth which can form societies and help each other in the difficult work of living4 ,among the mollusks1 the most important change is in the creation of the great1 strong swimming squids1 the most remarkable creatures of the sea4 ,some of these have arms that can stretch for fifty feet from tip to tip4 ,among the plants1 the most important change has been in the growth of flowering plants1 which have been constantly becoming more plenty1 and the plants which bear fruits have also become more numerous4 ,the broad-leaved trees seem to be constantly gaining on the forests of narrow-leaved cone-bearers1 which had in an earlier day replaced the forests of ferns4 ,in these ,tertiary ages1 as in the preceding times of the earth1 the lands and seas were much changed in their shape4 ,it seems that in the earlier ages the land had been mostly in the shape of large islands grouped close together where the continents now are4 ,in this time1 these islands grew together to form the united lands of ,europe1 ,asia1 ,africa1 ,australia1 and the twin ,american continents2 so that1 as life rose higher1 the earth was better fitted for it4 ,still there were great troubles that it had to undergo4 ,there were at least two different times during the ,tertiary age termed glacial periods1 times when the ice covered a large part of the northern continents1 compelling life of all sorts to abandon great regions1 and to find new places in more southern lands4 ,many kinds of animals and plants seem to have been destroyed in these journeys2 but these times of trial1 by removing the weaker and less competent creatures1 made room for new forms to rise in their places4 ,all advance in nature makes death necessary1 and this must come to races as well as to individuals if the life of the world is to go onward and upward4 ,looking back into the darkened past1 of which we yet know but little compared with what we would like to know1 we can see the great armies of living beings led onward from victory to victory toward the higher life of our own time4 ,each age sees some advance1 though death overtakes all its creatures4 ,those that escape their actual enemies or accident1 fall a prey to old age3 volcanoes1 earthquakes1 glacial periods1 and a host of other violent accidents sweep away the life of wide regions1 yet the host moves on under a control that lies beyond the knowledge of science4 ,man finds himself here as the crowning victory of this long war4 ,for him all this life appears to have striven4 ,in his hands lies the profit of all its toil and pain4 ,surely this should make us feel that our duty to all these living things1 that have shared in the struggle that has given man his elevation1 is great1 but above all1 great is our duty to the powers that have been placed in our bodies and our minds4 ,illustration3 ,a ,,glacier4 ,,the ,,pitch ,,lake ,,in ,,the ,,west ,,indies 7,,from ,,at ,,last47 ,,by ,c4 ,,kingsley4 ,illustration3 ,,coolie ,,and ,,negro4 ,the ,pitch ,lake1 like most other things1 owes its appearance on the surface to no convulsion or vagary at all1 but to a most slow1 orderly1 and respectable process of nature1 by which buried vegetable matter1 which would have become peat1 and finally brown coal1 in a temperate climate1 becomes1 under the hot tropic soil1 asphalt and oil1 continually oozing up beneath the pressure of the strata above it4444 99 99 99 99 99 ,as we neared the shore1 we perceived that the beach was black with pitch2 and the breeze being off the land1 the asphalt smell 7not unpleasant7 came off to welcome us4 ,we rowed in1 and saw in front of a little row of wooden houses a tall mulatto1 in blue policeman's dress1 gesticulating and shouting to us4 ,he was the ward policeman1 and ,i found him 7as ,i did all the colored police7 able and courteous1 shrewd and trusty4 ,these police are excellent specimens of what can be made of the negro1 or half-negro1 if he be but first drilled1 and then given a responsibility which calls out his self-respect4 ,he was warning our crew not to run aground on one or other of the pitch reefs1 which here take the place of rocks4 ,a large one1 a hundred yards off on the left1 has been almost all dug away1 and carried to ,new ,york or to ,paris to make asphalt-pavement4 ,illustration3 ,,the ,,police ,,station4 ,the boat was run ashore1 under his directions1 on a spit of sand between the pitch2 and when she ceased bumping up and down in the muddy surf1 we scrambled out into a world exactly the hue of its inhabitants of every shade1 from jet black to copper-brown4 ,the pebbles on the shore were pitch4 ,a tide-pool close by was enclosed in pitch2 a four-eyes was swimming about in it1 staring up at us2 and when we hunted him1 tried to escape1 not by diving1 but by jumping on shore on the pitch1 and scrambling off between our legs4 ,while the policeman1 after profoundest courtesies1 was gone to get a mule-cart to take us up to the lake1 and planks to bridge its water channels1 we took a look round at this oddest of corners of the earth4 ,in front of us was the unit of civilization1--the police-station1 wooden1 on wooden stilts 7as all well-built houses are here71 to insure a draught of air beneath them4 ,we were1 of course1 asked to come in and sit down1 but preferred looking about1 under our umbrellas2 for the heat was intense4 ,the soil is half pitch1 half brown earth1 among which the pitch sweals in and out as tallow sweals from a candle4 ,it is always in slow motion under the heat of the tropic sun2 and no wonder if some of the cottages have sunk right and left in such a treacherous foundation4 ,a stone or brick house could not stand here2 but wood and palm-thatch are both light and tough enough to be safe1 let the ground give way as it will4 ,the soil1 however1 is very rich4 ,the pitch certainly does not injure vegetation1 though plants will not grow actually in it4 ,the first plants which caught our eyes were pine-apples1 for which ,la ,brea is famous4 ,the heat of the soil1 as well as the air1 brings them to special perfection4 ,they grow about anywhere1 unprotected by hedge or fence2 for the negroes here seem honest enough1 at least toward each other2 and at the corner of the house was a bush worth looking at1 for we had heard of it for many a year4 ,it bore prickly1 heart-shaped pods an inch long1 filled with seeds coated with a red waxy pulp4 ,this was a famous plant--,bixa orellana ,roucou2 and that pulp was the well-known annotto dye of commerce4 ,in ,england and ,holland it is used merely1 ,i believe1 to color cheeses1 but in the ,spanish ,main to color human beings4 ,the ,indian of the ,orinoco prefers paint to clothes2 and when he has roucoued himself from head to foot1 considers himself in full dress1 whether for war or dancing4 ,doubtless he knows his own business best from long experience4 ,indeed1 as we stood broiling on the shore1 we began somewhat to regret that ,european manners and customs prevented our adopting the ,guaraon and ,arrawak fashion4 ,illustration3 ,,the ,,mule-,,cart4 ,the mule-cart arrived2 the lady of the party was put into it on a chair1 and slowly bumped and rattled past the corner of ,dundonald ,street--so named after the old sea-hero1 who was1 in his life-time1 full of projects for utilizing this same pitch--and up in pitch road1 with a pitch gutter on each side4 ,the pitch in the road has been1 most of it1 laid down by hand1 and is slowly working down the slight incline1 leaving pools and ruts full of water1 often invisible1 because covered with a film of brown pitch-dust1 and so letting in the unwary walker over his shoes4 ,the pitch in the gutter-bank is in its native place1 and as it spues slowly out of the soil into the ditch in odd wreaths and lumps1 we could watch1 in little1 the process which has produced the whole deposit--probably the whole lake itself4 ,a bullock-cart1 laden with pitch1 came jolting down past us1 and we observed that the lumps1 when the fracture is fresh1 have all a drawn out look2 that the very air bubbles in them1 which are often very numerous1 are all drawn out likewise1 long and oval1 like the air-bubbles in some ductile lavas4 ,on our left1 as we went on1 the bush was low1 all of yellow cassia and white ,hibiscus1 and tangled with lovely convolvulus-like creepers1 ,ipomoea and ,echites1 with white1 purple or yellow flowers4 ,on the right were negro huts and gardens1 fewer and fewer as we went on1--all rich with fruit trees1 especially with oranges1 hung with fruit of every hue2 and beneath them1 of course1 the pine-apples of ,la ,brea4 ,everywhere along the road grew1 seemingly wild here1 that pretty low tree1 ,cashew1 with rounded yellow-veined leaves and little green flowers1 followed by a quaint pink and red-striped pear1 from which hangs1 at the larger and lower end1 a kidney-shaped bean1 which bold folk eat when roasted2 but woe to those who try it when raw2 for the acrid oil blisters the lips1 and even while the beans are roasting the fumes of the oil will blister the cook's face if she holds it too near the fire4 ,as we went onward up the gentle slope 7the rise is one hundred and thirty-eight feet in rather more than a mile71 the ground became more and more full of pitch1 and the vegetation poorer and more rushy1 till it resembled1 on the whole1 that of an ,english fen4 ,an ,ipomoea or two1 and a scarlet flowered dwarf ,heliconia1 kept up the tropic type1 as does a stiff brittle fern about two feet high4 ,we picked the weeds1 which looked like ,english mint or basil1 and found that most of them had three longitudinal nerves in each leaf1 and were really ,melastomas1 though dwarfed into a far meaner habit than that of the noble forms we saw at ,chaguanas1 and again on the other side of the lake4 ,on the right1 too1 in a hollow1 was a whole wood of ,groogroo palms1 gray stemmed1 gray leaved1 and here and there a patch of white or black ,roseau rose gracefully eight or ten feet high among the reeds4 ,the plateau of pitch now widened out1 and the whole ground looked like an asphalt pavement1 half overgrown with marsh-loving weeds1 whose roots feed in the sloppy water which overlies the pitch4 ,but1 as yet1 there was no sign of the lake4 ,the incline1 though gentle1 shuts off the view of what is beyond4 ,this last lip of the lake has surely overflowed1 and is overflowing still1 though very slowly4 ,its furrows all curve downward2 and it is1 in fact1 as one of our party said1 a black glacier4 ,the pitch1 expanding under the burning sun of day1 must needs expand most toward the line of least resistance--that is1 downhill2 and when it contracts again under the coolness of night1 it contracts1 surely1 from the same cause1 more downhill than uphill2 and so each particle never returns to the spot whence it started1 but rather drags the particles above it downward toward itself4 ,at least1 so it seemed to us4 ,thus may be explained the common mistake which is noticed by ,messrs4 ,wall and ,sawkins in their admirable description of the lake4 ,all previous descriptions refer the bituminous matter scattered over the ,la ,brea district1 and especially that between the village and the lake1 to streams which have issued at some former epoch from the lake1 and extended into the sea4 ,this supposition is totally incorrect1 as solidification would probably have ensued before it had proceeded one-tenth of the distance2 and such of the asphalt as has undoubtedly escaped from the lake has not advanced more than a few yards1 and always presents the curved surfaces already described1 and never appears as an extended sheet4 ,agreeing with this statement as a whole1 ,i nevertheless cannot but think it probable that a great deal of the asphalt1 whether it be in large masses or in scattered veins1 may be moving very slowly down hill1 from the lake to the sea1 by the process of expansion by day and contraction by night1 and may be likened to a caterpillar1 or rather caterpillars innumerable1 progressing by expanding and contracting their rings1 having strength enough to crawl down hill1 but not strength enough to back up hill again4 ,at last we surmounted the last rise1 and before us lay the famous lake--not at the bottom of a depression1 as we expected1 but at the top of a rise1 whence the ground slopes away from it on two sides1 and rises from it very slightly on the two others4 ,the black pool glared and glittered in the sun4 ,a group of islands1 some twenty yards wide1 were scattered about the middle of it4 ,beyond it rose a double forest of ,moriche fan-palms2 and to the right of them high wood with giant ,mombins and undergrowth of ,cocorite--a paradise on the other side of the ,stygian pool4 ,illustration3 ,,the ,,pitch ,,lake4 ,we walked1 with some misgivings1 on to the asphalt1 and found it perfectly hard4 ,in a few steps we were stopped by a channel of clear water1 with tiny fish and water-beetles in it2 and1 looking round1 saw that the whole lake was intersected with channels1 so unlike anything which can be seen elsewhere that it is not easy to describe them4 ,conceive a crowd of mushrooms1 of all shapes1 from ten to fifty feet across1 close together side by side1 their tops being kept at exactly the same level1 their rounded rims squeezed tight against each other2 then conceive water poured on them so as to fill the parting seams1 and in the wet season1 during which we visited it1 to overflow the tops somewhat4 ,thus would each mushroom represent1 tolerably well1 one of the innumerable flat asphalt bosses1 which seem to have sprung up each from a separate centre1 while the parting seams would be of much the same shape as those in the asphalt1 broad and shallow atop1 and rolling downward in a smooth curve1 till they are at bottom mere cracks from two to ten feet deep4 ,whether these cracks actually close up below1 and the two contiguous masses of pitch become one1 cannot be seen4 ,as far as the eye goes down1 they are two1 though pressed close to each other4 ,messrs4 ,wall and ,sawkins explain the odd fact clearly and simply4 ,the oil1 they say1 which the asphalt contains when it rises first1 evaporates in the sun1 of course most on the outside of the heap1 leaving a thorough coat of asphalt1 which has1 generally1 no power to unite with the corresponding coat of the next mass4 ,meanwhile ,mr4 ,manross1 an ,american gentleman1 who has written a very clever and interesting account of the lake1 seems to have been so far deceived by the curved and squeezed edges of these masses that he attributes to each of them a revolving motion1 and supposes that the material is continually passing from the centre to the edges1 when it rolls under1 and rises again in the middle4 ,certainly the strange stuff looks1 at the first glance1 as if it were behaving in this way2 and certainly1 also1 his theory would explain the appearance of sticks and logs in the pitch4 ,but ,messrs4 ,wall and ,sawkins say that they have observed no such motion3 nor did we2 and ,i agree with them1 that it is not very obvious to what force1 or what influence1 it could be attributable4 ,we must1 therefore1 seek some other way of accounting for the sticks--which utterly puzzled us1 and which ,mr4 ,manross well describes as numerous pieces of wood1 which1 being involved in the pitch1 are constantly coming to the surface4 ,they are often several feet in length1 and five or six inches in diameter4 ,on reaching the surface they generally assume an upright position1 one end being detained in the pitch1 while the other is elevated by the lifting of the middle4 ,they may be seen at frequent intervals over the lake1 standing up to the height of two or even three feet4 ,they look like stumps of trees protruding through the pitch2 but their parvenu character is curiously betrayed by a ragged cap of pitch which invariably covers the top1 and hangs down like hounds' ears on either side4 ,whence do they come8 ,have they been blown on to the lake1 or left behind by man8 or are they fossil trees1 integral parts of the vegetable stratum below which is continually rolling upward8 or are they of both kinds8 ,i do not know4 ,only this is certain1 as ,messrs4 ,wall and ,sawkins have pointed out1 that not only the purer varieties of asphalt1 such as approach or are identical with asphalt glance1 have been observed 7though not1 ,i think1 in the lake itself7 in isolated masses1 where there was little doubt of their proceeding from ligneous substances of larger dimensions1 such as roots and pieces of trunks and branches1 but1 moreover1 that it is also necessary to admit a species of conversion by contact1 since pieces of wood included accidentally in the asphalt1 for example1 by dropping from overhanging vegetation1 are often found partially transformed into the material4 ,this is a statement which we verified again and again1 as we did the one which follows1 namely1 that the hollow bubbles which abound on the surface of the pitch generally contain traces of the lighter portion of vegetation1 and are manifestly derived from leaves1 etc41 which are blown about the lake by the wind1 and are covered with asphalt1 and1 as they become asphalt themselves1 give off gases which form bubbles round them4 ,but how is it that those logs stand up out of the asphalt1 with asphalt caps and hounds' ears 7as ,mr4 ,manross well phrases it7 on the tops of them8 ,we pushed on across the lake1 over the planks which the negroes laid down from island to island4 ,some1 meanwhile1 preferred a steeple-chase with water-jumps1 after the fashion of the midshipmen on a certain second visit to the lake4 ,how the negroes grinned delight and surprise at the vagaries of ,english lads--a species of animal altogether new to them2 and how they grinned still more when certain staid and portly dignitaries caught the infection1 and proved by more than one good leap that they too had been ,english school-boys--alas6 long1 long ago4 ,so1 whether by bridging1 leaping1 or wading1 we arrived at the little islands1 and found them covered with a thick1 low scrub2 deep sedge1 and among them ,pinguins1 like huge pine-apples without the apple2 gray wild-pines1 parasites on ,matapalos1 which1 of course1 have established themselves1 like robbers and vagrants as they are1 everywhere2 a true holly1 with box-like leaves2 and a rare cocoa-plum1 very like the holly in habit1 which seems to be all but confined to these little patches of red earth1 afloat on the pitch4 ,out of the scrub1 when we were there1 flew off two or three night-jars1 very like our ,english species1 save that they had white in the wings2 and on the second visit one of the midshipmen1 true to the ,english boy's bird's-nesting instinct1 found one of their eggs1 white-spotted1 in a grass nest4 ,passing these little islands1 which are said 7,i know not how truly7 to change their places and number1 we came to the very fountains of ,styx1 to that part of the lake where the asphalt is still oozing up4 ,as the wind set toward us1 we soon became aware of an evil smell--petroleum and sulphureted hydrogen at once--which gave some of us a headache4 ,the pitch here is yellow and white with sulphur foam2 so are the water-channels2 and out of both water and pitch innumerable bubbles of gas arise1 loathsome to the smell4 ,we became aware that the pitch was soft under our feet4 ,we left the impression of our boots2 and if we had stood still awhile1 we should soon have been ankle-deep4 ,no doubt there are spots where1 if a man stayed long enough1 he would be slowly and horribly engulfed4 ,but1 as ,mr4 ,manross says truly1 in no place is it possible to form those bowl-like depressions round the observer described by former travellers4 ,what we did see is that the fresh pitch oozes out at the lines of least resistance1 namely1 in the channels between the older and more hardened masses1 usually at the upper ends of them1 so that one may stand on pitch comparatively hard1 and put one's hand into pitch quite liquid1 which is flowing softly out1 like some ugly fungoid growth1 such as may be seen in old wine-cellars1 into the water4 ,one such pitch-fungus had grown several yards in length in the three weeks between our first and second visit2 and on another1 some of our party performed exactly the same feat as ,mr4 ,manross4 ,in one of the star-shaped pools of water1 some five feet deep1 a column of pitch had been forced perpendicularly up from the bottom4 ,on reaching the surface of the water it had formed a sort of centre-table1 about four feet in diameter1 but without touching the sides of the pool4 ,the stem was about a foot in diameter4 ,i leaped out on this table1 and found that it not only sustained my weight1 but that the elasticity of the stem enabled me to rock it from side to side4 ,pieces torn from the edges of this table sank readily1 showing that it had been raised by pressure1 and not by its buoyancy4 ,true1 though strange2 but stranger still did it seem to us when we did at last what the negroes asked us1 and dipped our hands into the liquid pitch1 to find that it did not soil the fingers4 ,the old proverb that one cannot touch pitch without being defiled happily does not stand true here1 or the place would be intolerably loathsome4 ,it can be scraped up1 moulded into any shape you will1 wound in a string 7as was done by one of the midshipmen7 round a stick1 and carried off2 but nothing is left on the hand save clean gray mud and water4 ,it may be kneaded for an hour before the mud be sufficiently driven out of it to make it sticky4 ,this very abundance of earthy matter it is which1 while it keeps the pitch from soiling1 makes it far less valuable than it would be were it pure4 ,it is easy to understand whence this earthy matter 7twenty or thirty per cent7 comes4 ,throughout the neighborhood the ground is full1 to the depth of hundreds of feet1 of coaly and asphaltic matter4 ,layers of sandstone or of shale containing this decayed vegetable alternate with layers which contain none2 and if1 as seems probable1 the coaly matter is continually changing into asphalt and oil1 and then working its way upward through every crack and pore1 to escape from the enormous pressure of the superincumbent soil1 it must needs carry up with it innumerable particles of the soils through which it passes4 ,in five minutes we had seen1 handled1 and smelt enough to satisfy us with this very odd and very nasty vagary of tropic nature2 and as we did not wish to become faint and ill between the sulphureted hydrogen and the blaze of the sun reflected off the hot black pitch1 we hurried on over the water-furrows1 and through the sedge-beds to the farther shore--to find ourselves1 in a single step1 out of an ,inferno into a ,paradise4 ,illustration ,a ,,stalagmite ,,cave 7,,from ,,the ,,voyage ,,of ,,the ,,challenger47 ,,by ,,sir ,c4 ,,wyville ,,thomson1 ,,kt41 ,,ll4,d41 ,,etc4 ,illustration ,i think the ,painter's ,vale cave is the prettiest of the whole4 ,the opening is not very large4 ,it is an arch over a great mass of dbris forming a steep slope into the cave1 as if part of the roof of the vault had suddenly fallen in4 ,at the foot of the bank of dbris one can barely see in the dim light the deep clear water lying perfectly still and reflecting the roof and margin like a mirror4 ,we clambered down the slope1 and as the eye became more accustomed to the obscurity the lake stretched further back4 ,there was a crazy little punt moored to the shore1 and after lighting candles ,captain ,nares rowed the ,governor back into the darkness1 the candles throwing a dim light for a time--while the voices became more hollow and distant--upon the surface of the water and the vault of stalactite1 and finally passing back as mere specks into the silence4 ,illustration3 ,a ,,guide4 ,after landing the ,governor on the opposite side1 ,captain ,nares returned for me1 and we rowed round the weird little lake4 ,it was certainly very curious and beautiful2 evidently a huge cavity out of which the calcareous sand had been washed or dissolved1 and whose walls1 still to a certain extent permeable1 had been hardened and petrified by the constant percolation of water charged with carbonate of lime4 ,from the roof innumerable stalactites1 perfectly white1 often several yards long and coming down to the delicacy of knitting-needles1 hung in clusters2 and wherever there was any continuous crack in the roof or wall1 a graceful1 soft-looking curtain of white stalactite fell1 and often ended1 much to our surprise4 ,deep in the water ,stalagmites also rose up in pinnacles and fringes through the water1 which was so exquisitely still and clear that it was something difficult to tell where the solid marble tracery ended1 and its reflected image began4 ,in this cave1 which is a considerable distance from the sea1 there is a slight change of level with the tide sufficient to keep the water perfectly pure4 ,the mouth of the cave is overgrown with foliage1 and every tree is draped and festooned with the fragrant ,jasminum gracile1 mingled not unfrequently with the poison ivy 7,rhus toxicodendron74 ,the ,bermudians1 especially the dark people1 have a most exaggerated horror of this bush4 ,they imagine that if one touch it or rub against it he becomes feverish1 and is covered with an eruption4 ,this is no doubt entirely mythical4 ,the plant is very poisonous1 but the perfume of the flower is rather agreeable1 and we constantly plucked and smelt it without its producing any unpleasant effect4 ,the tide was with us when we regained the ,flats ,bridge1 and the galley shot down the rapid like an arrow1 the beds of scarlet sponges and the great lazy trepangs showing perfectly clearly on the bottom at a fathom depth4 ,illustration3 ,,fig4 #a4 ,,calcareous ,,concretion ,,simulating ,a ,,fossil ,,palm-,,stem1 ,,boaz ,,island1 ,,bermudas4 ,every here and there throughout the islands there are groups of bodies of very peculiar form projecting from the surface of the limestone where it has been weathered4 ,these have usually been regarded as fossil palmetto stumps1 the roots of trees which have been overwhelmed with sand and whose organic matter has been entirely removed and replaced by carbonate of lime4 ,fig4 #a represents one of the most characteristic of these from a group on the side of the road in ,boaz ,island4 ,it is a cylinder a foot in diameter and six inches or so high2 the upper surface forms a shallow depression an inch deep surrounded by a raised border2 the bottom of the cup is even1 and pitted over with small depressions like the marks of rain-drops on sand2 the walls of the cylinder seem to end a few inches below the surface of the limestone in a rounded boss1 and all over this there are round markings or little cylindrical projections like the origins of rootlets4 ,the object certainly appears to agree even in every detail with a fossil palm-root1 and as the palmetto is abundant on the islands and is constantly liable to be destroyed by and ultimately enveloped in a mass of moving sand1 it seemed almost unreasonable to question its being one4 ,still something about the look of these things made me doubt1 with ,general ,nelson1 whether they were fossil palms1 or indeed whether they were of organic origin at all2 and after carefully examining and pondering over several groups of them1 at ,boaz ,island1 on the shore at ,mount ,langton1 and elsewhere1 ,i finally came to the conclusion that they were not fossils1 but something totally different4 ,illustration3 ,,fig4 #b4 ,,calcareous ,,concretion ,,in ,,aeolian ,,limestone1 ,,bermudas4 ,illustration3 ,,fig4 #c4 ,,calcareous ,,concretion ,,in ,,aeolian ,,limestone1 ,,bermudas4 ,illustration3 ,,fig4 #d4 ,,calcareous ,,concretion1 ,,bermudas4 ,illustration3 ,,fig4 #e4 ,,calcareous ,,concretion ,,in ,,aeolian ,,limestone1 ,,bermudas4 ,the form given in ,fig4 #a is the most characteristic1 and probably by far the most common2 but very frequently one of a group of these1 one which is evidently essentially the same as the rest and formed in the same way1 has an oval or an irregular shape 7,figs4 #b1 #c1 and #d74 ,in these we have the same raised border1 the same scars on the outside1 the same origins of root-like fibres1 and the same pitting of the bottom of the shallow cup2 but their form precludes the possibility of their being tree-roots4 ,in some cases 7,fig4 #e71 a group of so-called palm-stems is inclosed in a space surrounded by a ridge1 and on examining it closely this outer ridge is found to show the same leaf-scars and traces of rootlets as the palm-stems themselves4 ,in some cases very irregular honey-combed figures are produced which the examination of a long series of intermediate forms shows to belong to the same category 7,fig4 #f74 ,illustration3 ,,fig4 #f4 ,,concretions ,,in ,,aeolian ,,rocks1 ,,bermudas4 ,in the caves in the limestone1 owing to a thread of water having found its way in a particular direction through the porous stone of the roof1 a drop falls age after age on one spot on the cave-floor1 accurately directed by the stalactite which it is all the time creating4 ,the water contains a certain proportion of carbonate of lime1 which is deposited as stalagmite as the water evaporates1 and thus a ring-like crust is produced at a little distance from the spot where the drop falls4 ,when a ring is once formed1 it limits the spread of the drop1 and determines the position of the wall bounding the little pool made by the drop4 ,the floor of the cave gradually rises by the accumulation of sand and travertine1 and with it rise the walls and floor of the cup by the deposit of successive layers of stalagmite produced by the drop percolating into the limestone of the floor which hardens it still further1 but in this peculiar symmetrical way4 ,from the floor and sides of the cup the water oozes into the softer limestone around and beneath2 but1 as in all these limestones1 it does not ooze indiscriminately1 but follows certain more free paths4 ,these become soon lined and finally blocked with stalagmite1 and it is these tubes and threads of stalagmite which afterwards in the pseudo-fossil represent the diverging rootlets4 ,illustration3 ,a ,,stalagmite ,,cave4 ,sometimes when two or more drops fall from stalactites close to one another the cups coalesce 7,figs4 #b1 #c1 and #d72 sometimes one drop or two is more frequent than the other1 and then we have the form shown in ,figs4 #c and #d2 sometimes many drops irregularly scattered form a large pool with its raised border1 and a few drops more frequent and more constant than the rest grow their palmetto stems within its limit 7,fig4 #e72 and sometimes a number of drops near one another make a curious regular pattern1 with the partitions between the recesses quite straight 7,fig4 #f74 ,i have already referred to the rapid denudation which is going on in these islands1 and to the extent to which they have been denuded within comparatively recent times4 ,the floors of caves1 from their being cemented into a nearly homogeneous mass by stalagmitic matter1 are much harder than the ordinary porous blown limestone2 and it seems that in many cases1 after the rocks forming the walls and roof have been removed1 disintegration has been at all events temporarily arrested by the floor4 ,where there is a flat surface of rock exposed anywhere on the island1 it very generally bears traces of having been at one time the floor of a cave2 and as the weather-wearing of the surface goes on1 the old concretionary structures are gradually brought out again1 the parts specially hardened by a localized slow infiltration of lime resist integration longest and project above the general surface4 ,often a surface of weathered rock is so studded with these symmetrical concretions1 that it is hard to believe that one is not looking at the calcified stumps of a close-growing grove of palms4 ,illustration ,,the ,,big ,,trees ,,of ,,california 7,,from ,,studies ,,scientific ,,and ,,social47 ,,by ,,alfred ,,russel ,,wallace4 ,illustration ,in the popular accounts of these trees it is usual to dwell only on the dimensions of the very largest known specimens1 and sometimes even to exaggerate these4 ,even the smaller full-grown trees1 however1 are of grand dimensions1 varying from fourteen to eighteen feet in diameter1 at six feet above the ground1 and keeping nearly the same thickness for perhaps a hundred feet4 ,in the south ,calaveras grove1 where there are more than a thousand trees1 the exquisite beauty of the trunks is well displayed by the numerous specimens in perfect health and vigor4 ,the bark of these trees1 seen at a little distance1 is of a bright orange brown tint1 delicately mottled with darker shades1 and with a curious silky or plush-like gloss1 which gives them a richness of color far beyond that of any other conifer4 ,the tree which was cut down soon after the first discovery of the species1 the stump of which is now covered with a pavilion1 is twenty-five feet in diameter at six feet above the ground1 but this is without the thick bark1 which would bring it to twenty-seven feet when alive4 ,a considerable portion of this tree still lies where it fell1 and at one hundred and thirty feet from the base ,i found it to be still twelve and a half feet in diameter 7or fourteen feet with the bark71 while at the extremity of the last piece remaining1 two hundred and fifteen feet from its base1 it is six feet in diameter1 or at least seven feet with the bark4 ,the height of this tree when it was cut down is not recorded1 but as one of the living trees is more than three hundred and sixty feet high1 it is probable that this giant was not much short of four hundred feet4 ,illustration3 ,,the ,,mother ,,of ,,the ,,forest4 ,in the accompanying picture the dead tree in the centre is that from which the bark was stripped1 which was erected in the ,crystal ,palace and unfortunately destroyed by fire4 ,it is called the ,mother of the ,forest4 ,the two trees nearer the foreground are healthy1 medium-sized trees1 about fifteen feet diameter at six feet above the ground4 ,the huge decayed trunk called ,father of the ,forest1 which has fallen perhaps a century or more1 exhibits the grandest dimensions of any known tree4 ,by measuring its remains1 and allowing for the probable thickness of the bark1 it seems to have been about thirty-five feet diameter near the ground1 at ninety feet up fifteen feet1 and even at a height of two hundred and seventy feet1 it was nine feet in diameter4 ,it is within the hollow trunk of this tree that a man on horse-back can ride--both man and horse being rather small2 but the dimensions undoubtedly show that it was considerably larger than the ,pavilion tree1 and that it carried its huge dimensions to a greater altitude2 and although this does not prove it to have been much taller1 yet it was in all probability more than four hundred feet in height4 ,illustration ,very absurd statements are made to visitors as to the antiquity of these trees1 three or four thousand years being usually given as their age4 ,this is founded on the fact that while many of the large ,sequoias are greatly damaged by fire1 the large pines and firs around them are quite uninjured4 ,as many of these pines are assumed to be near a thousand years old1 the epoch of the great fire is supposed to be earlier still1 and as the ,sequoias have not outgrown the fire-scars in all that time1 they are supposed to have then arrived at their full growth4 ,but the simple explanation of these trees alone having suffered so much from fire is1 that their bark is unusually thick1 dry1 soft1 and fibrous1 and it thus catches fire more easily and burns more readily and for a longer time than that of the other conifer4 ,forest fires occur continually1 and the visible damage done to these trees has probably all occurred in the present century4 ,professor ,c4,b4 ,bradley1 of the ,university of ,california1 has carefully counted the rings of annual growth on the stump of the ,pavilion tree1 and found them to be twelve hundred and forty2 and after considering all that has been alleged as to the uncertainty of this mode of estimating the age of a tree1 he believes that in the climate of ,california1 in the zone of altitude where these trees grow1 the seasons of growth and repose are so strongly marked that the number of annual rings gives an accurate result4 ,other points that have been studied by ,professor ,bradley are1 the reason why there are so few young trees in the groves1 and what is the cause of the destruction of the old trees4 ,to take the last point first1 these noble trees seem to be singularly free from disease or from decay due to old age4 ,all the trees that have been cut down are solid to the heart1 and none of the standing trees show any indications of natural decay4 ,the only apparent cause for their overthrow is the wind1 and by noting the direction of a large number of fallen trees it is found that the great majority of them lie more or less towards the south4 ,this is not the direction of the prevalent winds1 but many of the tallest trees lean towards the south1 owing to the increased growth of their topmost branches towards the sun4 ,they are then acted upon by violent gales1 which loosen their roots1 and whatever the direction of the wind that finally overthrows them1 they fall in the direction of the over-balancing top weight4 ,the young trees grow spiry and perfectly upright1 but as soon as they overtop the surrounding trees and get the full influence of the sun and wind1 the highest branches grow out laterally1 killing those beneath their shade1 and thus a dome-shaped top is produced4 ,taking into consideration the health and vigor of the largest trees1 it seems probable that1 under favorable conditions of shelter from violent winds1 and from a number of trees around them of nearly equal height1 big trees might be produced far surpassing in height and bulk any that have yet been discovered4 ,it is to be hoped that if any such are found to exist in the extensive groves of these trees to the south of those which are alone accessible to tourists1 the ,californian ,government will take steps to reserve a considerable tract containing them1 for the instruction and delight of future generations4 ,the scarcity of young ,sequoias strikes every visitor1 the fact being that they are only to be found in certain favored spots4 ,these are1 either where the loose dbris of leaves and branches which covers the ground has been cleared away by fire1 or on the spots where trees have been uprooted4 ,here the young trees grow in abundance1 and serve to replace those that fall4 ,the explanation of this is1 that during the long summer drought the loose surface dbris is so dried up that the roots of the seedling ,sequoias perish before they can penetrate the earth beneath4 ,they require to germinate on the soil itself1 and this they are enabled to do when the earth is turned up by the fall of a tree1 or where a fire has cleared off the dbris4 ,they also flourish under the shade of the huge fallen trunks in hollow places1 where moisture is preserved throughout the summer4 ,most of the other conifers of these forests1 especially the pines1 have much larger seeds than the ,sequoias1 and the store of nourishment in these more bulky seeds enables the young plants to tide over the first summer's drought4 ,it is clear1 therefore1 that there are no indications of natural decay in these forest giants4 ,in every stage of their growth they are vigorous and healthy1 and they have nothing to fear except from the destroying hand of man4 ,illustration3 ,,redwood ,,tree ,,with ,,triple ,,trunk4 ,destruction from this cause is1 however1 rapidly diminishing both the giant ,sequoia and its near ally the noble redwood 7,sequoia sempervirens71 a tree which is more beautiful in foliage and in some other respects more remarkable than its brother species1 while there is reason to believe that under favorable conditions it reaches an equally phenomenal size4 ,it once covered almost all the coast ranges of central and northern ,california1 but has been long since cleared away in the vicinity of ,san ,francisco1 and greatly diminished elsewhere4 ,a grove is preserved for the benefit of tourists near ,santa ,cruz1 the largest tree being two hundred and ninety-six feet high1 twenty-nine feet diameter at the ground and fifteen feet at six feet above it4 ,one of these trees having a triple trunk is here figured from a photograph4 ,much larger trees1 however1 exist in the great forests of this tree in the northern part of the ,state2 but these are rapidly being destroyed for the timber1 which is so good and durable as to be in great demand4 ,hence ,californians have a saying that the redwood is too good a tree to live4 ,on the mountains a few miles east of the ,bay of ,san ,francisco1 there are a number of patches of young redwoods1 indicating where large trees have been felled1 it being a peculiarity of this tree that it sends up vigorous young plants from the roots of old ones immediately around the base4 ,hence in the forests these trees often stand in groups arranged nearly in a circle1 thus marking out the size of the huge trunks of their parents4 ,it is from this quality that the tree has been named sempervirens1 or ever flourishing4 ,dr4 ,gibbons1 of ,alameda1 who has explored all the remains of the redwood forests in the neighborhood of ,oakland1 kindly took me to see the old burnt-out stump of the largest tree he had discovered4 ,it is situated about fifteen hundred feet above the sea1 and is thirty-four feet in diameter at the ground4 ,this is as large as the very largest specimens of the ,sequoia gigantea1 but it may have spread out more at the base and have been somewhat smaller above1 though this is not a special characteristic of the species4 ,illustration ,,what ,,is ,,evolution8 7,,from ,,the ,,atlantic ,,monthly1 ,,march1 '#ic47 ,,by ,,professor ,e4,s4 ,,holden4 ,illustration ,i was once trying to tell a boy1 a friend of mine1 what the scientific men mean by the long word ,evolution1 and to give him some idea of the plan of the world4 ,i wanted an illustration of something that had grown--evolved1 developed--from small beginnings up through more and more complicated forms1 till it had reached some very complete form4 ,i could think of no better example than the railway by which we were sitting4 ,the trains were running over the very track where a wagon-road had lately been1 and before that a country cart-track1 and before that a bridle-path1 and before that again a mere trail for cattle4 ,so ,i took the road for an example1 and tried to show my boy how it had grown from little things by slow degrees according to laws2 and if you like1 ,i will try to tell it again4 ,just as one can go further and further back1 and always find a bird to be the parent of the egg1 and an egg to be the parent of that bird1 so in the history of this road of ours2 we may go back and back into the past1 always finding something earlier1 which is the cause of the something later4 ,the earth1 the planets1 and the sun were all a fiery mist long ago4 ,and in that mist1 and in what came before it1 we may look for the origin of things as they are4 ,but we must begin somewhere4 ,let us begin with the landscape as we see it now1--hills1 valleys1 streams1 mountains1 grass1--but with only a single tree4 ,we will not try to say how the tree came there4 ,at least1 we will not try just yet4 ,when we are through with the story you can say just as well as ,i can4 ,suppose1 then1 a single oak-tree stood just on that hillside thousands and thousands of years ago4 ,grass was growing everywhere1 and flowers1 too4 ,the seeds came with the winds4 ,year after year the oak-tree bore its acorns1 hundreds and hundreds of them1 and they fell on the grass beneath and rolled down the smooth slopes1 and sprouted as best they could1--most of them uselessly so far as producing trees were concerned1--but each one did its duty and furnished its green sprout1 and died if it found no nourishment4 ,all the hundreds of acorns rolled down the slopes1 ,not one rolled up2 and here was a law1--the law of gravitation1--in full activity4 ,there were scores of other laws active1 too2 for evolution had gone a long way when we had an earth fit to be lived on1 and hills in their present shape1 and a tree bearing acorns that would reproduce their kind4 ,but ever since the fiery mist this simple law of gravitation has been acting1 binding the whole universe together1 making a relationship between each clod and every other clod1 and forcing every stone1 every acorn1 and every rain-drop to move down and not up4 ,just as this law operates1--continuously1 silently1 inexorably1--so every other law makes itself felt in its own sphere4 ,gravitation is simple4 ,the law according to which an acorn makes an oak--and not a pine-tree is complex4 ,but the laws of ,nature are all alike1 and if we understand the simple ones1 we can at least partly comprehend the more complex4 ,they are nothing but fixed habits on a large scale4 ,so the acorns fell year by year and sprouted2 and one out of a thousand found good soil1 and was not wasted1 and made a tree4 ,and so all around 7below7 the tree with which we started there grew a grove of oaks like it1 in fact its children2 and finally the original trees died1 but not without having left successors4 ,first of all1 the green hillside is smooth and untrodden4 ,there is nothing but grass and flowers1 borne there by the winds1 which leave no track4 ,there is no animal life even in this secluded spot save the birds1 and they too leave no track4 ,by and by there comes a hard winter1 or a dearth of food1 and a pair of stray squirrels emigrate from their home in the valley below2 and the history of our hill and its woods begins4 ,mere chance decides the choice of the particular oak-tree in which the squirrels make their home4 ,from the foot of this tree they make excursions here and there for their store of winter food1--acorns and the like1--and they leave little paths on the hillside from tree to tree4 ,the best-marked paths run to the places where there are the most acorns4 ,a little later on there are more squirrels in the colony1--the young of the parent pair1 and other colonists from the valley4 ,the little tracks become plainer and plainer4 ,later still come other wild animals in search of food1--squirrels will do4 ,the wild animals do not remain in the colony 7there are too few squirrels1 and they are too hard to catch71 but they pass through it1 sometimes by day but oftenest by night4 ,you might think it was perfectly a matter of chance along which path a bear or a wolf passed1 but it was not4 ,he could walk anywhere on the hillside2 and sometimes he would be found far out of the paths that the squirrels had begun4 ,but usually1 when he was in no haste1 he took the easiest path4 ,the easiest one was that which went between the bushes and not through them2 along the hillside and not straight up it2 around the big rocks and not over them4 ,the wolves and bears and foxes have new and different wants when they come2 and they break new paths to the springs where they drink1 to the shade where they lie1 to the hollow trees where the bees swarm and store the wild honey4 ,but the squirrels were the first surveyors of these tracks4 ,the bears and wolves are the engineers1 who change the early paths to suit their special convenience4 ,by and by the ,indian hunter comes to follow the wild game4 ,he1 too1 takes the easiest trail1 the path of least resistance2 and he follows the track to the spring that the deer have made1 and he drinks there4 ,he is an animal as they are1 and he satisfies his animal wants according to the same law that governs them4 ,after generations of hunters1 ,indians1 and then white men1 there comes a man on horseback looking for a house to live in4 ,he1 too1 follows along the easiest paths and stops at the spring2 and near by he finds the place he is looking for4 ,soon he returns1 driving before him herds of cattle and flocks of sheep1 which spread over the grassy glades to feed4 ,but everywhere they take the easiest place1 the old paths1 from the shady tree to the flowing spring4 ,after awhile the hillside is plainly marked with these sheep trails4 ,you can see them now whenever you go into the country1 on every hillside4 ,soon there are neighbors who build their homes in the next valley1 and a good path must be made between the different houses4 ,a few days' work spent in moving the largest stones1 in cutting down trees1 and in levelling off a few steep slopes1 makes a trail along which you can gallop your horse4 ,things move fast now1--history begins to be made quickly as soon as man takes a hand in it4 ,soon the trail is not enough3 it must be widened so that a wagon-load of boards for a new house can be carried in 7for the settler has found a wife74 ,after the first cart-track is made to carry the boards and shingles in1 a better road will be needed to haul firewood and grain out 7for the wants of the new family have increased1 and things must be bought in the neighboring village with money1 and money can only be had by selling the products of the farm74 ,by and by the neighborhood is so well inhabited that it is to the advantage of the villages all around it to have good and safe and easy roads there2 and the road is declared a public one1 and it is regularly kept in repair and improved at the public expense4 ,do not forget the squirrels of long ago4 ,they were the projectors of this road4 ,their successors use it now1--men and squirrels alike1--and stop at the spring to drink1 and under the huge oaks to rest4 ,a few years more1 and it becomes to the advantage of all to have a railway through the valley and over the hillside4 ,then a young surveyor1 just graduated from college1 comes with his chain-men and flag-men1 and finds that the squirrels1 and bears1 and hunters1 and all the rest have picked out the easiest way for him long centuries ago4 ,he makes his map1 and soon the chief enigneer and the president of the road drive along in a buggy with a pair of fast horses 7frightening the little squirrels off their road-way and into their holes71 and the route of the ,bear ,valley and ,quercus ,railway is finally selected1 and here it is4 ,see6 there comes a train along the track4 ,this is the way a railway route grew out of a squirrel path4 ,there are thousands of little steps1 but you can trace them1 or imagine them1 as well as ,i can tell you4 ,it is the same all over the world4 ,stanley cut a track through the endless ,african forests4 ,but it lay between the ,pygmy villages1 along the paths they had made1 and through the glades where they fought their battles with the storks4 ,sometimes the first road is a river--the track is already cut4 ,try to find out where the settlements in ,america were in the very early days--before #ahjj4 ,you will find them along the ,hudson1 the ,juanita1 the ,st4 ,lawrence1 the ,james1 the ,mississippi ,rivers4 ,but when these are left1 men follow the squirrel-tracks and bear-tracks1 or the paths of hunters1 or the roads of ,roman soldiers4 ,it is a standing puzzle to little children why all the great rivers flow past the great towns4 7,why do they87 ,the answer to that question will tell you why the great battles are fought in the same regions2 why ,egypt has been the coveted prize of a dozen different conquerors 7it is the gateway of the ,east72 why our ,civil ,war turned on the possession of the ,mississippi ,river4 ,it is the roadways we fight for1 the ways in and out1 whether they be land or water4 ,of course1 we really fought for something better than the mere possession of a roadway1 but to get what we fought for we had to have the roadway first4 ,the great principle at the bottom of everything in ,nature is that the fittest survives3 or1 as ,i think it is better to say it1 in any particular conflict or struggle that thing survives which is the fittest to survive in this particular struggle4 ,this is ,mr4 ,darwin's discovery1--or one of them1--and the struggle for existence is a part of the great struggle of the whole universe1 and the laws of it make up the methods of ,evolution--of ,development4 ,it is clear now1 is it not1 how the railway route is the direct descendant of the tiny squirrel track between two oaks8 ,the process of development we call ,evolution1 and you can trace it all around you4 ,why are your skates shaped in a certain way8 ,why is your gun rifled8 ,why have soldiers two sets of 7now7 useless buttons on the skirts of their coats8 7,i will give you three guesses for this1 and the hint that you must think of cavalry soldiers47 ,why are eagles' wings of just the size that they are8 ,these and millions of like questions are to be answered by referring to the principle of development4 ,sometimes it is hard to find the clew4 ,sometimes the development has gone so far1 and the final product has become so complex and special1 that it takes a good deal of thinking to find out the real reasons4 ,but they can be found1 whether they relate to a fashion1 to one of the laws of our country1 or to the colors on a butterfly's wing4 ,there is a little piece of verse intended to be comic1 which1 on the contrary1 is really serious and philosophical1 if you understand it4 ,learn it by heart1 and apply it to all kinds and conditions of things1 and see if it does not help you to explain them to yourself4444 ,and ,man grew a thumb for that he had need of it1 ,and developed capacities for prey4 ,for the fastest men caught the most animals1 ,and the fastest animals got away from the most men4 ,whereby all the slow animals were eaten1 ,and all the slow men starved to death4 ,illustration ,,how ,,the ,,soil ,,is ,,made 7,,from ,,the ,,formation ,,of ,,vegetable ,,mould47 ,,by ,,charles ,,darwin4 ,illustration3 ,w ,worms have played a more important part in the history of the world than most persons would at first suppose4 ,in almost all humid countries they are extraordinarily numerous1 and for their size possess great muscular power4 ,in many parts of ,england a weight of more than ten tons 7#aj1eaf kilogrammes7 of dry earth annually passes through their bodies and is brought to the surface on each acre of land2 so that the whole superficial bed of vegetable mould passes through their bodies in the course of every few years4 ,from the collapsing of the old burrows the mould is in constant though slow movement1 and the particles composing it are thus rubbed together4 ,by these means fresh surfaces are continually exposed to the action of the carbonic acid in the soil1 and of the humus-acids which appear to be still more efficient in the decomposition of rocks4 ,the generation of the humus-acids is probably hastened during the digestion of the many half-decayed leaves which worms consume4 ,thus the particles of earth1 forming the superficial mould1 are subjected to conditions eminently favorable for their decomposition and disintegration4 ,moreover1 the particles of the softer rocks suffer some amount of mechanical trituration in the muscular gizzards of worms1 in which small stones serve as mill-stones4 ,illustration3 ,,diagram ,,of ,,the ,,alimentary ,,canal ,,of ,,an ,,earth-,,worm4 ,the finely levigated castings1 when brought to the surface in a moist condition1 flow during rainy weather down any moderate slope2 and the smaller particles are washed far down even a gently inclined surface4 ,castings when dry often crumble into small pellets and these are apt to roll down any sloping surface4 ,where the land is quite level and is covered with herbage1 and where the climate is humid so that much dust cannot be blown away1 it appears at first sight impossible that there should be any appreciable amount of sub-aerial denudation2 but worm castings are blown1 especially while moist and viscid1 in one uniform direction by the prevalent winds which are accompanied by rain4 ,by these several means the superficial mould is prevented from accumulating to a great thickness2 and a thick bed of mould checks in many ways the disintegration of the underlying rocks and fragments of rock4 ,illustration3 ,a ,,worm ,,casting1 ,,from ,,nice4 7,natural ,size47 ,the removal of worm-castings by the above means leads to results which are far from insignificant4 ,it has been shown that a layer of earth14#b of an inch in thickness1 is in many places annually brought to the surface per acre2 and if a small part of this amount flows1 or rolls1 or is washed1 even for a short distance1 down every inclined surface1 or is repeatedly blown in one direction1 a great effect will be produced in the course of ages4 ,it was found by measurements and calculations that on a surface with a mean inclination of #i #bf'1 #b4d cubic inches of earth which had been ejected by worms crossed1 in the course of a year1 a horizontal line one yard in length2 so that two hundred and forty cubic inches would cross a line one hundred yards in length4 ,this latter amount in a damp state would weigh eleven and one-half pounds4 ,thus1 a considerable weight of earth is continually moving down each side of every valley1 and will in time reach its bed4 ,finally1 this earth will be transported by the streams flowing in the valleys into the ocean1 the great receptacle for all matter denuded from the land4 ,it is known from the amount of sediment annually delivered into the sea by the ,mississippi1 that its enormous drainage-area must on an average be lowered4#jjbfc of an inch each year2 and this would suffice in four and a half million years to lower the whole drainage-area to the level of the seashore4 ,so that if a small fraction of the layer of fine earth14#b of an inch in thickness1 which is annually brought to the surface by worms1 is carried away1 a great result cannot fail to be produced within a period which no geologist considers extremely long4 ,illustration3 ,,section ,,through ,,one ,,of ,,the ,,druidical ,,stones ,,at ,,stonehenge1 ,,showing ,,how ,,much ,,it ,,had ,,sunk ,,into ,,the ,,ground4 7,scale1 #a_/b inch to #a foot47 ,archaeologists ought to be grateful to worms1 as they protect and preserve for an indefinitely long period every object1 not liable to decay1 which is dropped on the surface of the land1 by burying it beneath their castings4 ,thus1 also1 many elegant and curious tesselated pavements and other ancient remains have been preserved2 though no doubt the worms have in these cases been largely aided by earth washed and blown from the adjoining land1 especially when cultivated4 ,the old tesselated pavements have1 however1 often suffered by having subsided unequally from being unequally undermined by the worms4 ,even old massive walls may be undermined and subside2 and no building is in this respect safe1 unless the foundations lie six or seven feet beneath the surface1 at a depth at which worms cannot work4 ,it is probable that many monoliths and some old walls have fallen down from having been undermined by worms4 ,worms prepare the ground in an excellent manner for the growth of fibrous-rooted plants and for seedlings of all kinds4 ,they periodically expose the mould to the air1 and sift it so that no stones larger than the particles which they can swallow are left in it4 ,they mingle the whole intimately together1 like a gardener who prepares fine soil for his choicest plants4 ,in this state it is well fitted to retain moisture and to absorb all soluble substances1 as well as for the process of nitrification4 ,the bones of dead animals1 the harder parts of insects1 the shells of land mollusks1 leaves1 twigs1 etc41 are before long all buried beneath the accumulated castings of worms1 and are thus brought in a more or less decayed state within reach of the roots of plants4 ,worms likewise drag an infinite number of dead leaves and other parts of plants into their burrows1 partly for the sake of plugging them up and partly as food4 ,the leaves which are dragged into the burrows as food1 after being torn into the finest shreds1 partially digested and saturated with the intestinal and urinary secretions1 are commingled with much earth4 ,this earth forms the dark-colored1 rich humus which almost everywhere covers the surface of the land with a fairly well-defined layer or mantle4 ,von ,hensen placed two worms in a vessel eighteen inches in diameter1 which was filled with sand1 on which fallen leaves were strewed2 and these were soon dragged into their burrows to a depth of three inches4 ,after about six weeks an almost uniform layer of sand1 a centimetre 74#d inch7 in thickness1 was converted into humus by having passed through the alimentary canals of these two worms4 ,it is believed by some persons that worm-burrows1 which often penetrate the ground almost perpendicularly to a depth of five or six feet1 materially aid in its drainage2 notwithstanding that the viscid castings piled over the mouths of the burrows prevent or check the rain-water directly entering them4 ,they allow the air to penetrate deeply into the ground4 ,they also greatly facilitate the downward passage of roots of moderate size2 and these will be nourished by the humus with which the burrows are lined4 ,many seeds owe their germination to having been covered by castings2 and others buried to a considerable depth beneath accumulated castings lie dormant1 until at some future time they are accidentally uncovered and germinate4 ,illustration3 ,a ,,worm ,,casting ,,from ,,south ,,india4 7,natural ,size47 ,worms are poorly provided with sense-organs1 for they cannot be said to see1 although they can just distinguish between light and darkness2 they are completely deaf1 and have only a feeble power of smell2 the sense of touch alone is well developed4 ,they can1 therefore1 learn little about the outside world1 and it is surprising that they should exhibit some skill in lining their burrows with their castings and with leaves1 and in the case of some species in piling up their castings into tower-like constructions4 ,but it is far more surprising that they should apparently exhibit some degree of intelligence instead of a mere blind1 instinctive impulse1 in their manner of plugging up the mouths of their burrows4 ,they act in nearly the same manner as would a man1 who had to close a cylindrical tube with different kinds of leaves1 petioles1 triangles of paper1 etc41 for they commonly seize such objects by their pointed ends4 ,but with thin objects a certain number are drawn in by their broader ends4 ,they do not act in the same unvarying manner in all cases1 as do most of the lower animals2 for instance1 they do not drag in leaves by their foot-stalks1 unless the basil part of the blade is as narrow as the apex1 or narrower than it4 99 99 99 99 99 ,when we behold a wide1 turf-covered expanse1 we should remember that its smoothness1 on which so much of its beauty depends1 is mainly due to all the inequalities having been slowly levelled by worms4 ,it is a marvellous reflection that the whole of the superficial mould over any such expanse has passed1 and will again pass1 every few years through the bodies of worms4 ,the plough is one of the most ancient and most valuable of man's inventions2 but long before he existed the land was in fact regularly ploughed1 and1 still continues to be thus ploughed by earth-worms4 ,it may be doubted whether there are many other animals which have played so important a part in the history of the world1 as have these lowly organized creatures4 ,some other animals1 however1 still more lowly organized1 namely1 corals1 have done far more conspicuous work in having constructed innumerable reefs and islands in the great oceans2 but these are almost confined to the tropical zones4 ,illustration ,,zo,,logical ,,myths 7,,from ,,facts ,,and ,,fictions ,,of ,,zo,,logy47 ,,by ,,andrew ,,wilson4 ,illustration ,when the country swain1 loitering along some lane1 comes to a standstill to contemplate1 with awe and wonder1 the spectacle of a mass of the familiar hair-eels or hair-worms wriggling about in a pool1 he plods on his way firmly convinced that1 as he has been taught to believe1 he has just witnessed the results of the transformation of some horse's hairs into living creatures4 ,so familiar is this belief to people of professedly higher culture than the countryman1 that the transformation just alluded to has to all1 save a few thinking persons and zologists1 become a matter of the most commonplace kind4 ,when some quarrymen1 engaged in splitting up the rocks1 have succeeded in dislodging some huge mass of stone1 there may sometimes be seen to hop from among the dbris a lively toad or frog1 which comes to be regarded by the excavators with feelings akin to those of superstitious wonder and amazement4 ,the animal may or may not be captured2 but the fact is duly chronicled in the local newspapers1 and people wonder for a season over the phenomenon of a veritable ,rip ,van ,winkle of a frog1 which to all appearance1 has lived for thousands of years in the solid rock4 ,nor do the hair-worm and the frog stand alone in respect of their marvellous origin4 ,popular zology is full of such marvels4 ,we find unicorns1 mermaids1 and mermen2 geese developed from the shell-fish known as barnacles2 we are told that crocodiles may weep1 and that sirens can sing--in short1 there is nothing so wonderful to be told of animals that people will not believe the tale4 ,whilst1 curiously enough1 when they are told of veritable facts of animal life1 heads begin to shake and doubts to be expressed1 until the zologist despairs of educating people into distinguishing fact from fiction1 and truth from theories and unsupported beliefs4 ,the story told of the old lady1 whose youthful acquaintance of seafaring habits entertained her with tales of the wonders he had seen1 finds1 after all1 a close application in the world at large4 ,the dame listened with delight1 appreciation1 and belief1 to accounts of mountains of sugar and rivers of rum1 and to tales of lands where gold and silver and precious stones were more than plentiful4 ,but when the narrator descended to tell of fishes that were able to raise themselves out of the water in flight1 the old lady's credulity began to fancy itself imposed upon2 for she indignantly repressed what she considered the lad's tendency to exaggeration1 saying1 ,sugar mountains may be1 and rivers of rum may be1 but fish that flee ne'er can be6 ,many popular beliefs concerning animals partake of the character of the old lady's opinions regarding the real and fabulous2 and the circumstance tells powerfully in favor of the opinion that a knowledge of our surroundings in the world1 and an intelligent conception of animal and plant life1 should form part of the school-training of every boy and girl1 as the most effective antidote to superstitions and myths of every kind4 ,illustration3 ,,flying ,,fish4 ,the tracing of myths and fables is a very interesting task1 and it may1 therefore1 form a curious study1 if we endeavor to investigate very briefly a few of the popular and erroneous beliefs regarding lower animals4 ,the belief regarding the origin of the hair-worms is both widely spread and ancient4 ,shakespeare tells us that ,much1 is breeding ,which1 like the courser's hair1 hath1 yet but life1 ,and not a serpent's poison4 ,the hair-worms certainly present the appearance of long1 delicate black hairs1 which move about with great activity amidst the mud of pools and ditches4 ,these worms1 in the early stages of their existence1 inhabit the bodies of insects1 and may be found coiled up within the grasshopper1 which thus gives shelter to a guest exceeding many times the length of the body of its host4 ,sooner or later the hair-worm1 or ,gordius aquaticus as the naturalist terms it1 leaves the body of the insect1 and lays its eggs1 fastened together in long strings1 in water4 ,from each egg a little creature armed with minute hooks is produced1 and this young hair-worm burrows its way into the body of some insect1 there to repeat the history of its parent4 ,such is the well-ascertained history of the hair-worm1 excluding entirely the popular belief in its origin4 ,there certainly does exist in science a theory known as that of spontaneous generation1 which1 in ancient times1 accounted for the production of insects and other animals by assuming that they were produced in some mysterious fashion out of lifeless matter4 ,but not even the most ardent believer in the extreme modification of this theory which holds a place in modern scientific belief1 would venture to maintain the production of a hair-worm by the mysterious vivification of an inert substance such as a horse's hair4 ,the expression crocodile's tears has passed into common use1 and it therefore may be worth while noting the probable origin of this myth4 ,shakespeare1 with that wide extent of knowledge which enabled him to draw similes from every department of human thought1 says that ,gloster's show ,beguiles him1 as the mournful crocodile ,with sorrow snares relenting passengers4 ,the poet thus indicates the belief that not only do crocodiles shed tears1 but that sympathizing passengers1 turning to commiserate the reptile's woes1 are seized and destroyed by the treacherous creatures4 ,that quaint and credulous old author--the earliest writer of ,english prose--,sir ,john ,mandeville1 in his ,voiage1 or account of his ,travile1 published about #acef--;in which1 by the way1 there are to be found accounts of not a few wonderful things in the way of zological curiosities--tells us that in a certain contre and be all yonde1 ben great plenty of ,crokodilles1 that is1 a manner of a long ,serpent as ,i have seyed before4 ,he further remarks that these ,serpents slew men1 and devoured them1 weeping2 and he tells us1 too1 that whan thei eaten thei meven 7move7 the over jowe 7upper jaw71 and nought the nether 7lower7 jowe3 and thei have no tonge 7tongue74 ,sir ,john thus states two popular beliefs of his time and of days prior to his age1 namely1 that crocodiles move their upper jaws1 and that a tongue was absent in these animals4 ,illustration3 ,,crocodile4 ,as regards the tears of the crocodile1 no foundation of fact exists for the belief in such sympathetic exhibitions4 ,but a highly probable explanation may be given of the manner in which such a belief originated4 ,these reptiles unquestionably emit very loud and singularly plaintive cries1 compared by some travellers to the mournful howling of dogs4 ,the earlier and credulous travellers would very naturally associate tears with these cries1 and1 once begun1 the supposition would be readily propagated1 for error and myth are ever plants of quick growth4 ,the belief in the movement of the upper jaw rests on apparent basis of fact4 ,the lower jaw is joined to the skull very far back on the latter1 and the mouth-opening thus comes to be singularly wide2 whilst1 when the mouth opens1 the skull and upper jaw are apparently observed to move4 ,this is not the case1 however2 the apparent movement arising from the manner in which the lower jaw and the skull are joined together4 ,the belief in the absence of the tongue is even more readily explained4 ,when the mouth is widely opened1 no tongue is to be seen4 ,this organ is not only present1 but is1 moreover1 of large size2 it is1 however1 firmly attached to the floor of the mouth1 and is specially adapted1 from its peculiar form and structure1 to assist these animals in the capture and swallowing of their prey4 ,one of the most curious fables regarding animals which can well be mentioned1 is that respecting the so-called ,bernicle or ,barnacle ,geese1 which by the naturalists and educated persons of the ,middle ,ages were believed to be produced by those little ,crustaceans named ,barnacles4 ,with the ,barnacles every one must be familiar who has examined the floating driftwood of the sea-beach1 or who has seen ships docked in a seaport town4 ,a barnacle is simply a kind of crab enclosed in a triangular shell1 and attached by a fleshy stalk to fixed objects4 ,if the barnacle is not familiar to readers1 certain near relations of these animals must be well known1 by sight at least1 as amongst the most familiar denizens of our sea-coast4 ,these latter are the ,sea-,acorn1 or ,balani1 whose little conical shells we crush by hundreds as we walk over the rocks at low-water mark2 whilst every wooden pile immersed in the sea becomes coated in a short time with a thick crust of the ,sea-,acorns4 ,if we place one of these little animals1 barnacle1 or sea-acorn--the latter wanting the stalk of the former--in its native waters1 we shall observe a beautiful little series of feathery plumes to wave backward and forward1 and ever and anon to be quickly withdrawn into the secure recesses of the shell4 ,these organs are the modified feet of the animal1 which not only serve for sweeping food-particles into the mouth1 but act also as breathing-organs4 ,we may1 therefore1 find it a curious study to inquire through what extraordinary transformation and confusion of ideas such an animal could be credited with giving origin to a veritable goose2 and the investigation of the subject will also afford a singularly apt illustration of the ready manner in which the fable of one year or period becomes transmitted and transformed into the secure and firm belief of the next4 ,we may begin our investigation by inquiring into some of the opinions which were entertained on this subject and ventilated by certain old writers4 ,between #aaed and #aahi ,giraldus ,cambrensis1 in a work entitled ,topographia ,hiberniae1 written in ,latin1 remarks concerning many birds which are called ,bernacae3 against nature1 nature produces them in a most extraordinary way4 ,they are like marsh geese1 but somewhat smaller4 ,they are produced from fir timber tossed along the sea1 and are at first like gum4 ,afterward they hang down by their beaks1 as if from a seaweed attached to the timber1 surrounded by shells1 in order to grow more freely1 ,giraldus is here evidently describing the barnacles themselves4 ,he continues3 ,having thus1 in process of time1 been clothed with a strong coat of feathers1 they either fall into the water or fly freely away into the air4 ,they derive their food and growth from the sap of the wood or the sea1 by a secret and most wonderful process of alimentation4 ,i have frequently1 with my own eyes1 seen more than a thousand of these small bodies of birds1 hanging down on the seashore from one piece of timber1 enclosed in shells1 and already formed4 ,here1 again1 our author is speaking of the barnacles themselves1 with which he naturally confuses the geese1 since he presumes the ,crustaceans are simply geese in an undeveloped state4 ,he further informs his readers that1 owing to their presumably marine origin1 bishops and clergymen in some parts of ,ireland do not scruple to dine off these birds at the time of fasting1 because they are not flesh1 nor born of flesh1 although for certain other and theological reasons1 not specially requiring to be discussed in the present instance1 ,giraldus disputes the legality of this practice of the ,hibernian clerics4 ,in the year #aebg appeared ,the ,hystory and ,croniclis of ,scotland1 with the cosmography and dyscription thairof1 compilit be the noble ,clerk ,maister ,hector ,boece1 ,channon of ,aberdene4 ,boece's ,history was written in ,latin2 the title we have just quoted being that of the ,english version of the work 7#aedj71 which title further sets forth that ,boece's work was ,translait laitly in our vulgar and commoun langage be ,maister ,johne ,bellenden1 ,archedene of ,murray1 ,and ,imprentit in ,edinburgh1 be me ,thomas ,davidson1 prenter to the ,kyngis nobyll grace4 ,in this learned work the author discredits the popular ideas regarding the origin of the geese4 ,some men belevis that thir clakis 7geese7 growis on treis be the nebbis 7bills74 ,bot thair opinoun is vane4 ,and becaus the nature and procreatioun of thir clakis is strange1 we have maid na lytyll laboure and deligence to serche ye treuth and verite yairof1 we have salit 7sailed7 throw ye seis quhare thir clakis ar bred1 and ,i fynd be gret experience1 that the nature of the seis is mair relevant caus of thair procreatioun than ony uthir thyng4 ,according to ,boece1 then1 the nature of the seis formed the chief element in the production of the geese1 and our author proceeds to relate how all treis 7trees7 that ar casein in the seis be proces of tyme apperis first wormeetin 7worm-eaten71 and in the small boris and hollis 7holes7 thairof growis small worms4 ,our author no doubt here alludes to the ravages of the ,teredo1 or ship-worm1 which burrows into timber1 and with which the barnacles themselves are thus confused4 ,then he continues1 the wormis first schaw 7show7 thair heid and feit1 and last of all thay schaw thair plumis and wyngis4 ,finaly1 quhen thay ar cumyn to the just mesure and quantite of geis1 thay fle in the aire as othir fowlis dois1 as was notably provyn1 in the yeir of ,god ane thousand iii hundred lxxxx1 in sicht of mony pepyll1 besyde the castell of ,petslego4 ,on the occasion referred to1 ,boece tells us that a great tree was cast on shore1 and was divided1 by order of the laird of the ground1 by means of a saw4 ,wonderful to relate1 the tree was found not merely to be riddled with a multitude of wormis1 throwing themselves out of the holes of the tree1 but some of the wormis had baith heid1 feit1 and wyngis1 but1 adds the author1 they had no fedderis 7feathers74 ,unquestionably1 either the scientific use of the imagination had operated in this instance in inducing the observers to believe that in this tree1 riddled by the ship-worms and possibly having barnacles attached to it1 they beheld young geese2 or ,boece had construed the appearances described as those representing the embryo stages of the barnacle geese4 ,boece further relates how a ship named the ,christofir was brought to ,leith1 and was broken down because her timbers had grown old and failing4 ,in these timbers were beheld the same wormeetin appearances1 all the hollis thairof being full of geis4 ,boece again most emphatically rejects the idea that the geis were produced from the wood of which the timbers were composed1 and once more proclaims his belief that the nature of the seis resolvit in geis may be accepted as the true and final explanation of their origin4 ,a certain ,maister ,alexander ,galloway had apparently strolled with the historian along the sea-coast1 the former giving his mynd with maist ernist besynes to serche the verite of this obscure and mysty dowtis4 ,lifting up a piece of tangle1 they beheld the seaweed to be hanging full of mussel-shells from the root to the branches4 ,maister ,galloway opened one of the mussel-shells1 and was mair astonis than afore to find no fish therein1 but a perfectly shaped foule1 smal and gret1 as corresponded to the quantity of the shell4 ,and once again ,boece draws the inference that the trees or wood on which the creatures are found have nothing to do with the origin of the birds2 and that the fowls are begotten of the occeane see1 quhilk1 concludes our author1 is the caus and production of mony wonderful thingis4 ,more than fifty years after the publication of ,boece's ,history1 old ,gerard of ,london1 the famous master in chirurgerie of his day1 gave an account of the barnacle goose1 and not only entered into minute particulars of its growth and origin1 but illustrated its manner of production by means of the engraver's art of his day4 ,gerard's ,herball1 published in #aeig1 thus contains1 amongst much that is curious in medical lore1 a very quaint piece of zological history4 ,he tells us that in the north parts of ,scotland1 and the ,hands adjacent1 called ,orchades 7,orkneys71 are found certaine trees1 whereon doe growe certaine shell fishes1 of a white colour tending to russet2 wherein are conteined little living creatures3 which shels in time of maturitie doe open1 and out of them grow those little living foules whom we call ,barnakles1 in the north of ,england ,brant ,geese1 and in ,lancashire tree ,geese2 but the other that do fall upon the land1 perish1 and come to nothing3 thus much by the writings of others1 and also from the mouths of people of those parts1 which may1 concludes ,gerard1 very well accord with truth4 ,not content with hearsay evidence1 however1 ,gerard relates what his eyes saw and hands touched4 ,he describes how on the coasts of a certain small ,hand in ,lancashire called ,pile of ,foulders 7probably ,peel ,island71 the wreckage of ships is cast up by the waves1 along with the trunks and branches of old and rotten trees4 ,on these wooden rejectamenta a certaine spume or froth grows1 according to ,gerard4 ,this spume in time breedeth unto certaine shels1 in shape like those of the muskle1 but sharper pointed1 and of a whitish color4 ,this description1 it may be remarked1 clearly applies to the barnacles themselves4 ,gerard then continues to point out how1 when the shell is perfectly formed1 it gapeth open1 and the first thing that appeereth is the foresaid lace or string--the substance described by ,gerard as contained within the shell--next come the legs of the ,birde hanging out2 and as it groweth greater1 it openeth the shell by degrees1 till at length it is all come forth1 and hangeth only by the bill2 in short space after it commeth to full maturitie1 and falleth into the sea1 where it gathereth feathers1 and groweth to a foule1 bigger than a ,mallard1 and lesser than a ,goose1 having blacke legs and bill or beake1 and feathers blacke and white 444 which the people of ,lancashire call by no other name than a tree ,goose4 ,illustration3 ,,fig4 #a4 ,,the ,,barnacle ,,tree4 7,from ,gerard's ,herball47 ,accompanying this description is the engraving of the barnicle tree 7,fig4 #a7 bearing its geese progeny4 ,from the open shells in two cases1 the little geese are seen protruding1 whilst several of the fully-fledged fowls are disporting themselves in the sea below4 ,gerard's concluding piece of information1 with its exordium1 must not be omitted4 ,they spawne1 says the wise apothecary1 as it were1 in ,march or ,aprill2 the ,geese are found in ,maie or ,june1 and come to fulnesse of feathers in the moneth after4 ,and thus hauing1 through ,god's assistance1 discoursed somewhat at large of ,grasses1 ,herbes1 ,shrubs1 ,trees1 ,mosses1 and certaine excrescences of the earth1 with other things moe incident to the ,historic thereof1 we conclude and end our present volume1 with this woonder of ,england4 ,for which ,god's name be euer honored and praised4 ,it is to be remarked that ,gerard's description of the goose-progeny of the barnacle tree exactly corresponds with the appearance of the bird known to ornithologists as the barnacle-goose2 and there can be no doubt that1 skilled as was this author in the natural history lore of his day1 there was no other feeling in his mind than that of firm belief in and pious wonder at the curious relations between the shells and their fowl-offspring4 ,gerard thus attributes the origin of the latter to the barnacles4 ,he says nothing of the wormeetin holes and burrows so frequently mentioned by ,boece1 nor would he have agreed with the latter in crediting the nature of the occeane see with their production1 save in so far as their barnacle-parents lived and existed in the waters of the ocean4 ,the last account of this curious fable which we may allude to in the present instance is that of ,sir ,robert ,moray1 who1 in his work entitled ,a ,relation concerning ,barnacles1 published in the ,philosophical ,transactions of the ,royal ,society in #afgg-gh1 gives a succinct account of these crustaceans and their bird-progeny4 ,sir ,robert is described as lately one of his ,majesties ,council for the ,kingdom of ,scotland1 and we may therefore justly assume his account to represent that of a cultured1 observant person of his day and generation4 ,the account begins by remarking that the most ordinary trees found in the western islands of ,scotland are ,firr and ,ash4 ,being1 continues ,sir ,robert1 in the ,island of ,east 7,uist71 ,i saw lying upon the shore a cut of a large ,firr tree of about #b-a_/b foot diameter1 and #i or #aj foot long2 which had lain so long out of the water that it was very dry3 ,and most of the shells that had formerly cover'd it1 were worn or rubb'd off4 ,only on the parts that lay next the ground1 there still hung multitudes of little ,shells2 having within them little ,birds1 perfectly shap'd1 supposed to be ,barnacles4 ,here again the description applies to the barnacles2 the little birds they are described as containing being of course the bodies of the shell-fish4 ,the ,shells1 continues the narrator1 hang at the ,tree by a ,neck longer than the ,shell2 this neck being represented by the stalk of the barnacle4 ,the neck is described as being composed of a kind of filmy substance1 round1 and hollow1 and creased1 not unlike the ,wind-pipe of a ,chicken2 spreading out broadest where it is fastened to the ,tree1 from which it seems to draw and convey the matter which serves for the growth and vegetation of the ,shell and the little ,bird within it4 ,sir ,robert ,moray therefore agrees in respect of the manner of nourishment of the barnacles with the opinion of ,giraldus already quoted4 ,the author goes on to describe the ,bird found in every shell he opened2 remarking that there appeared nothing wanting as to the internal parts1 for making up a perfect ,sea-fowl3 every little part appearing so distinctly1 that the whole looked like a large ,bird seen through a concave or diminishing ,glass1 colour and feature being everywhere so clear and neat4 ,the ,bird is most minutely described as to its bill1 eyes1 head1 neck1 breast1 wings1 tail1 and feet1 the feathers being everywhere perfectly shaped1 and blackish-coloured4 ,all being dead and dry1 says ,sir ,robert1 ,i did not look after the ,internal parts of them1 a statement decidedly inconsistent with his previous assertion as to the perfect condition of the internal parts2 and he takes care to add1 nor did ,i ever see any of the little ,birds alive1 nor met with anybody that did4 ,only some credible persons1 he concludes1 have assured me they have seen some as big as their fist4 ,illustration3 ,,fig4 #b4 ,,barnacle ,,tree4 7,from ,munster's ,cosmography47 ,this last writer thus avers that he saw little birds within the shells he clearly enough describes as those of the barnacles4 ,we must either credit ,sir ,robert with describing what he never saw1 or with misconstruing what he did see4 ,his description of the goose corresponds with that of the barnacle goose1 the reputed progeny of the shells2 and it would1 therefore1 seem that this author1 with the myth at hand1 saw the barnacles only with the eyes of a credulous observer1 and thus beheld1 in the inside of each shell--if1 indeed1 his research actually extended thus far--the reproduction in miniature of a goose1 with which1 as a mature bird1 he was well acquainted4 ,on p4 #aeg is a woodcut1 copied from ,munster's ,cosmography 7#aeej71 a very popular book in its time1 showing the tree with its fruit1 and the geese which are supposed to have just escaped from it4 ,this historical ramble may fitly preface what we have to say regarding the probable origin of the myth4 ,by what means could the barnacles become credited with the power of producing the well-known geese8 ,once started1 the progress and growth of the myth are easily accounted for4 ,the mere transmission of a fable from one generation or century to another is a simply explained circumstance1 and one exemplified by the practices of our own times4 ,the process of accretion and addition is also well illustrated in the perpetuation of fables2 since the tale is certain to lose nothing in its historical journey1 but1 on the contrary1 to receive additional elaboration with increasing age4 ,professor ,max ,mller1 after discussing various theories of the origin of the barnacle myth1 declares in favor of the idea that confusion of language and alteration of names lie at the root of the error4 ,the learned author of the ,science of ,language argues that the true barnacles were named1 properly enough1 ,bernaculae1 and lays stress on the fact that ,bernicle geese were first caught in ,ireland4 ,that country becomes ,hibernia in ,latin1 and the ,irish geese were accordingly named ,hibernicae1 or ,hiberniculae4 ,by the omission of the first syllable--no uncommon operation for words to undergo--we obtain the name ,berniculae for the geese1 this term being almost synonymous with the name ,bernaculae already applied1 as we have seen1 to the barnacles4 ,bernicle geese and bernicle shells1 confused in name1 thus became confused in nature2 and1 once started1 the ordinary process of growth was sufficient to further intensify1 and render more realistic1 the story of the bernicle tree and its wonderful progeny4 ,by way of a companion legend to that of the barnacle tree1 we may select the story of the ,lamb ,tree of ,cathay1 told by ,sir ,john ,mandeville1 whose notes of travel regarding crocodiles' tears1 and other points in the conformation of these reptiles1 have already been referred to4 ,sir ,john1 in that chapter of his work which treats ,of the ,contries and ,yles that ben bezonde the ,lond of ,cathay2 and of the ,frutes there1 etc41 relates that in ,cathay there growethe a manner of ,fruyt1 as thoughe it were ,gowrdes3 and whan thei ben rype1 men kutten 7cut7 hem a to 7them in two71 and men fyndem with inne a lytylle ,best 7beast71 in ,flessche in ,bon and ,blode 7bone and blood7 as though it were a lytylle ,lomb 7lamb7 with outen wolle 7without wool74 ,and men eaten both the ,frut and the ,best2 and that1 says ,sir ,john1 is a great marveylle4 ,of that frut1 he continues1 ,i have eten2 alle thoughe it were wondirfulle--this being added1 no doubt1 from an idea that there might possibly be some stay-at-home persons who would take ,sir ,john's statement cum grano salis4 ,but1 adds this worthy knyght of ,ingolond1 ,i knowe wel that ,god is marveyllous in ,his ,werkes4 ,not to be behind the inhabitants of ,cathay in a tale of wonders1 the knight related to these ,easterns als gret a marveylle to hem that is amonges us2 and that was of the ,bernakes4 ,for ,i tolde him hat in oure ,countree weren ,trees that beren a ,fruyt1 that becomen ,briddes 7birds7 fleeynge3 and tho that fellen in the ,water lyven 7live72 and thei that fallen on the ,erthe dyen anon3 and thei ben right gode to mannes mete 7man's meat74 ,and here had thei als gret marvayle1 concludes ,sir ,john1 that sume of hem trowed it were an impossible thing to be4 ,probably the inhabitants of ,cathay1 knowing their own weakness as regards the lamb tree1 might possess a fellow-feeling for their visitor's credulity1 knowing well1 from experience1 the readiness with which a gret marvayle could be evolved and sustained4 ,passing from the sphere of the mythical and marvellous as represented in mediaeval times1 we may shortly discuss a question1 which1 of all others1 may justly claim a place in the records of zological curiosities--namely1 the famous and oft-repeated story of the ,toad from the solid rock1 as the country newspapers style the incident4 ,regularly1 year by year1 and in company with the reports of the sea-serpent's reappearance1 we may read of the discoveries of toads and frogs in situations and under circumstances suggestive of a singular vitality on the part of the amphibians1 of more than usual credulity on the part of the hearers1 or of a large share of inventive genius in the narrators of such tales4 ,the question possesses for every one a certain degree of interest1 evoked by the curious and strange features presented on the face of the tales4 ,and it may therefore not only prove an interesting but also a useful study1 if we endeavor to arrive at some just and logical conceptions of these wonderful narrations4 ,illustration ,instances of the discovery of toads and frogs in solid rocks need not be specially given2 suffice it to say1 that these narratives are repeated year by year with little variation4 ,a large block of stone or face of rock is detached from its site1 and a toad or frog is seen hereafter to be hopping about in its usual lively manner4 ,the conclusion to which the bystanders invariably come is that the animal must have been contained within the rock1 and that it was liberated by the dislodgement of the mass4 ,now1 in many instances1 cases of the appearance of toads during quarrying operations have been found1 on close examination1 to present no evidence whatever that the appearance of the animals was due to the dislodgement of the stones4 ,a frog or toad may be found hopping about among some recently formed dbris1 and the animal is at once seized upon and reported as having emerged from the rocks into the light of day4 ,there is in such a case not the slightest ground for supposing any such thing2 and the animal may more reasonably be presumed to have simply hopped into the dbris from its ordinary habitat4 ,but laying aside narratives of this kind1 which lose their plausibility under a very commonplace scrutiny1 there still exist cases1 reported in an apparently exact and truthful manner1 in which these animals have been alleged to appear from the inner crevices of rocks after the removal of large masses of the formations4 ,we shall assume these latter tales to contain a plain1 unvarnished statement of what was observed1 and deal with the evidence they present on this footing4 ,illustration3 ,a ,,toad4 ,one or two notable examples of such verified tales are related by ,smellie1 in his ,philosophy of ,natural ,history4 ,thus1 in the ,memoirs of the ,french ,academy of ,sciences for #agai1 a toad is described as having been found in the heart of an elm tree2 and another is stated to have been found in the heart of an old oak tree1 in #agca1 near ,nantz4 ,the condition of the trees is not expressly stated1 nor are we afforded any information regarding the appearance of the toads--particulars of considerable importance in view of the suggestions and explanations to be presently brought forward4 ,smellie himself1 while inclined to be sceptical in regard to the truth or exactness of many of the tales told of the vitality of toads1 regards the matter as affording food for reflection1 since he remarks1 ,but ,i mean not to persuade1 for ,i cannot satisfy myself2 all ,i intend is1 to recommend to those gentlemen who may hereafter chance to see such rare phenomena1 a strict examination of every circumstance that can throw light upon a subject so dark and mysterious2 for the vulgar1 ever inclined to render uncommon appearances still more marvellous1 are not to be trusted4 ,this author strikes the key-note of the inquiry in his concluding words1 and we shall find that the explanation of the matter really lies in the clear understanding of what are the probabilities1 and what the actual details1 of the cases presented for consideration4 ,we may firstly1 then1 glance at a few of the peculiarities of the frogs and toads1 regarded from a zological point of view4 ,as every one knows1 these animals emerge from the egg in the form of little fish-like tadpoles1 provided with outside gills1 which are soon replaced by inside gills1 resembling those of fishes4 ,the hind legs are next developed1 and the fore limbs follow a little later2 whilst1 with the development of lungs1 and the disappearance of the gills and tail1 the animal leaves the water1 and remains for the rest of its life an air-breathing1 terrestrial animal4 ,then1 secondly1 in the adult frog or toad1 the naturalist would point to the importance of the skin as not only supplementing1 but1 in some cases1 actually supplanting the work of the lungs as the breathing organ4 ,frogs and toads will live for months under water1 and will survive the excision of the lungs for like periods2 the skin in such cases serving as the breathing surface4 ,a third point worthy of remembrance is included in the facts just related1 and is implied in the information that these animals can exist for long periods without food1 and with but a limited supply of air4 ,we can understand this toleration on the part of these animals when we take into consideration their cold-blooded habits1 which do not necessitate1 and which are not accompanied by1 the amount of vital activity we are accustomed to note in higher animals4 ,and1 as a last feature in the purely scientific history of the frogs and toads1 it may be remarked that these animals are known to live for long periods4 ,one pet toad is mentioned by a ,mr4 ,arscott as having attained1 to his knowledge1 the age of thirty-six years2 and a greater age still might have been recorded of this specimen1 but for the untoward treatment it sustained at the hands1 or rather beak1 of a tame raven4 ,in all probability it may be safely assumed that1 when the conditions of life are favorable1 these creatures may attain a highly venerable age--regarding the lapse of time from a purely human and interested point of view4 ,we may now inquire whether or not the foregoing considerations may serve to throw any light upon the tales of the quarryman4 ,the first point to which attention may be directed is that involved in the statement that the amphibian has been imprisoned in a solid rock4 ,much stress is usually laid on the fact that the rock was solid2 this fact being held to imply the great age1 not to say antiquity1 of the rock and its supposed tenant4 ,the impartial observer1 after an examination of the evidence presented1 will be inclined to doubt greatly the justification for inserting the adjective solid2 for usually no evidence whatever is forthcoming as to the state of the rock prior to its removal4 ,no previous examination of the rock is or can be made1 from the circumstance that no interest can possibly attach to its condition until its removal reveals the apparent wonder it contained1 in the shape of the live toad4 ,and it is equally important to note that we rarely1 if ever1 find mention of any examination of the rock being made subsequently to the discovery4 ,hence1 a first and grave objection may be taken to the validity of the supposition that the rock was solid1 and it may be fairly urged that on this supposition the whole question turns and depends4 ,for if the rock cannot be proved to have been impermeable to and barred against the entrance of living creatures1 the objector may proceed to show the possibility of the toad having gained admission1 under certain notable circumstances1 to its prison-house4 ,the frog or toad in its young state1 and having just entered upon its terrestrial life1 is a small creature1 which could1 with the utmost ease1 wriggle into crevices and crannies of a size which would almost preclude such apertures being noticed at all4 ,gaining access to a roomier crevice or nook within1 and finding there a due supply of air1 along with a dietary consisting chiefly of insects1 the animal would grow with tolerable rapidity1 and would increase to such an extent that egress through its aperture of entrance would become an impossibility4 ,next1 let us suppose that the toleration of the toad's system to starvation and to a limited supply of air is taken into account1 together with the fact that these creatures will hibernate during each winter1 and thus economize1 as it were1 their vital activity and strength2 and after the animal has thus existed for a year or two--no doubt under singularly hard conditions--let us imagine that the rock is split up by the wedge and lever of the excavator4 ,we can then readily enough account for the apparently inexplicable story of the toad in the rock4 ,there is the toad and here is the solid rock1 say the gossips4 ,there is an animal which has singular powers of sustaining life under untoward conditions1 and which1 in its young state1 could have gained admittance to the rock through a mere crevice1 says the naturalist in reply4 ,doubtless1 the great army of the unconvinced may still believe in the tale as told them2 for the weighing of evidence and the placing pros and cons in fair contrast are not tasks of congenial or wonted kind in the ordinary run of life4 ,some people there will be who will believe in the original solid rock and its toad1 despite the assertion of the geologists that the earliest fossils of toads appear in almost the last-formed rocks1 and that a live toad in rocks of very ancient age--presuming1 according to the popular belief1 that the animal was enclosed when the rock was formed--would be as great an anomaly and wonder as the mention1 as an historical fact1 of an express train or the telegraph in the days of the patriarchs4 ,in other words1 the live toad which hops out of an ,old ,red ,sandstone rock must be presumed1 on the popular belief1 to be older by untold ages than the oldest fossil frogs and toads4 ,the reasonable mind1 however1 will ponder and consider each feature of the case1 and will rather prefer to countenance a supposition based on ordinary experience1 than an explanation brought ready-made from the domain of the miraculous2 whilst not the least noteworthy feature of these cases is that included in the remark of ,smellie1 respecting the tendency of uneducated and superstitious persons to magnify what is uncommon1 and in his sage conclusion that as a rule such persons in the matter of their relations are not to be trusted4 ,but it must also be noted that we possess valuable evidence of a positive and direct kind bearing on the duration of life in toads under adverse circumstances4 ,as this evidence tells most powerfully against the supposition that the existence of those creatures can be indefinitely prolonged1 it forms of itself a veritable court of appeal in the cases under discussion4 ,the late ,dr4 ,buckland1 curious to learn the exact extent of the vitality of the toad1 caused1 in the year #ahbe1 two large blocks of stone to be prepared4 ,one of the blocks was taken from the olite limestone1 and in this first stone twelve cells were excavated4 ,each cell was one foot deep and five inches in diameter4 ,the mouth of each cell was grooved so as to admit of two covers being placed over the aperture2 the first or lower cover being of glass1 and the upper one of slate4 ,both covers were so adapted that they could be firmly luted down with clay or putty2 the object of this double protection being that the slate cover could be raised so as to inspect the contained object through the closed glass cover without admitting air4 ,in the second or sandstone block1 a series of twelve cells was also excavated2 these latter cells being1 however1 of smaller size than those of the limestone block1 each cell being only six inches in depth by five inches in diameter4 ,these cells were likewise fitted with double covers4 ,on ,november #bfth1 #ahbe1 a live toad--kept for some time previously to insure its being healthy--was placed in each of the twenty-four cells4 ,the largest specimen weighed #aahe grains1 and the smallest #aae grains4 ,the stones and the immured toads were buried on the day mentioned1 three feet deep1 in ,dr4 ,buckland's garden4 ,there they lay until ,december #ajth1 #ahbf1 when they were disinterred and their tenants examined4 ,all the toads in the smaller cells of the sandstone block were dead1 and from the progress of decomposition it was inferred that they had succumbed long before the date of disinterment4 ,the majority of the toads in the limestone block were alive1 and1 curiously enough1 one or two had actually increased in weight4 ,thus1 ,no4 #e1 which at the commencement of its captivity had weighed #aahe grains1 had increased to #abfe grains2 but the glass cover of ,no4 #e's cell was found to be cracked4 ,insects and air must therefore have obtained admittance and have afforded nourishment to the imprisoned toad2 this supposition being rendered the more likely by the discovery that in one of the cells1 the covers of which were also cracked and the tenant of which was dead1 numerous insects were found4 ,no4 #i1 weighing originally #ihh grains1 had increased during its incarceration to #aaaf grains2 but ,no4 #a1 which in the year #ahbe had weighed #ibd grains1 was found in ,december1 #ahbf1 to have decreased to #fih grains2 and ,no4 #aa1 originally weighing #icf grains1 had likewise disagreed with the imprisonment1 weighing only #feb grains when examined in #ahbf4 ,at the period when the blocks of stone were thus prepared1 four toads were pinned up in holes five inches deep and three inches in diameter1 cut in the stem of an apple-tree2 the holes being firmly plugged with tightly fitting wooden plugs4 ,these four toads were found to be dead when examined along with the others in #ahbf2 and of four others enclosed in basins made of plaster of ,paris1 and which were also buried in ,dr4 ,buckland's garden1 two were found to be dead at the end of a year1 their comrades being alive1 but looking starved and meagre4 ,the toads which were found alive in the limestone block in ,december1 #ahbf1 were again immured and buried1 but were found to be dead1 without leaving a single survivor1 at the end of the second year of their imprisonment4 ,these experiments may fairly be said to prove two points4 ,they firstly show that under circumstances even of a favorable kind when compared with the condition popularly believed in--namely1 that of being enclosed in a solid rock--the limit of the toad's life may be assumed to be within two years2 this period being no doubt capable of being extended when the animal gains a slight advantage1 exemplified by the admission of air and insect-food4 ,secondly1 we may reasonably argue that these experiments show that toads when rigorously treated1 like other animals1 become starved and meagre1 and by no means resemble the lively1 well-fed animals reported as having emerged from an imprisonment extending1 in popular estimation1 through periods of inconceivable duration4 ,these tales are1 in short1 as devoid of actual foundation as are the modern beliefs in the venomous properties of the toad1 or the ancient beliefs in the occult and mystic powers of various parts of its frame when used in incantations4 ,shakespeare1 whilst attributing to the toad venomous qualities1 has yet immortalized it in his famous simile by crediting it with the possession of a precious jewel4 ,but even in the latter case the animal gets but scant justice2 for science strips it of its poetical reputation1 and in this1 as in other respects1 shows it1 despite fable and myth1 to be zologically an interesting1 but otherwise a commonplace member of the animal series4 ,illustration ,,on ,a ,,piece ,,of ,,chalk ,a ,,lecture ,,to ,,working ,,men4 7,delivered in ,england47 ,,by ,t4,h4 ,,huxley4 ,illustration3 ,a ,,chalk ,,cliff4 ,if a well were to be sunk at our feet in the midst of the city of ,norwich1 the diggers would very soon find themselves at work in that white substance almost too soft to be called rock1 with which we are all familiar as chalk4 ,not only here1 but over the whole county of ,norfolk1 the well-sinker might carry his shaft down many hundred feet without coming to the end of the chalk2 and1 on the sea-coast1 where the waves have pared away the face of the land which breasts them1 the scarped faces of the high cliffs are often wholly formed of the same material4 ,northward1 the chalk may be followed as far as ,yorkshire2 on the south coast it appears abruptly in the picturesque western bays of ,dorset1 and breaks into the ,needles of the ,isle of ,wight2 while on the shores of ,kent it supplies that long line of white cliffs to which ,england owes her name of ,albion4 ,were the thin soil which covers it all washed away1 a curved band of white chalk1 here broader1 and there narrower1 might be followed diagonally across ,england from ,lulworth in ,dorset1 to ,flamborough ,head in ,yorkshire--a distance of over two hundred and eighty miles as the crow flies4 ,from this band to the ,north ,sea1 on the east1 and the ,channel1 on the south1 the chalk is largely hidden by other deposits2 but1 except in the ,weald of ,kent and ,sussex1 it enters into the very foundation of all the south-eastern counties4 ,attaining1 as it does in some places1 a thickness of more than a thousand feet1 the ,english chalk must be admitted to be a mass of considerable magnitude4 ,nevertheless1 it covers but an insignificant portion of the whole area occupied by the chalk formation of the globe1 which has precisely the same general character as ours1 and is found in detached patches1 some less1 and others more extensive1 than the ,english4 ,chalk occurs in north-west ,ireland2 it stretches over a large part of ,france--the chalk which underlies ,paris being1 in fact1 a continuation of that of the ,london basin2 it runs through ,denmark and ,central ,europe1 and extends southward to ,north ,africa2 while eastward1 it appears in the ,crimea and in ,syria1 and may be traced as far as the shores of the ,sea of ,aral1 in ,central ,asia4 ,if all the points at which true chalk occurs were circumscribed1 they would lie within an irregular oval about three thousand miles in long diameter--the area of which would be as great as that of ,europe1 and would many times exceed that of the largest existing inland sea--the ,mediterranean4 ,thus the chalk is no unimportant element in the masonry of the earth's crust1 and it impresses a peculiar stamp1 varying with the conditions to which it is exposed1 on the scenery of the districts in which it occurs4 ,the undulating downs and rounded coombs1 covered with sweet-grassed turf1 of our inland chalk country1 have a peacefully domestic and mutton-suggesting prettiness1 but can hardly be called either grand or beautiful4 ,but on our southern coasts1 the wall-sided cliffs1 many hundred feet high1 with vast needles and pinnacles standing out in the sea1 sharp and solitary enough to serve as perches for the wary cormorant1 confer a wonderful beauty and grandeur upon the chalk headlands4 ,and in the ,east1 chalk has its share in the formation of some of the most venerable of mountain ranges1 such as the ,lebanon4 99 99 99 99 99 ,what is this wide-spread component of the surface of the earth8 and whence did it come8 ,you may think this no very hopeful inquiry4 ,you may not unnaturally suppose that the attempt to solve such problems as these can lead to no result1 save that of entangling the inquirer in vague speculations1 incapable of refutation and of verification4 ,if such were really the case1 ,i should have selected some other subject than a piece of chalk for my discourse4 ,but1 in truth1 after much deliberation1 ,i have been unable to think of any topic which would so well enable me to lead you to see how solid is the foundation upon which some of the most startling conclusions of physical science rest4 ,a great chapter of the history of the world is written in the chalk4 ,few passages in the history of man can be supported by such an overwhelming mass of direct and indirect evidence as that which testifies to the truth of the fragment of the history of the globe1 which ,i hope to enable you to read1 with your own eyes1 to-night4 ,illustration3 ,,microscopic ,,section ,,of ,,chalk4 7,magnified nearly #cjj times47 #a4 ,textularia4 #b4 ,globigerina4 #c4 ,rotalia4 #d4 ,coccoliths4 ,let me add1 that few chapters of human history have a more profound significance for ourselves4 ,i weigh my words well when ,i assert1 that the man who should know the true history of the bit of chalk which every carpenter carries about in his breeches' pocket1 though ignorant of all other history1 is likely1 if he will think his knowledge out to its ultimate results1 to have a truer1 and therefore a better1 conception of this wonderful universe1 and of man's relation to it1 than the most learned student who is deep-read in the records of humanity and ignorant of those of nature4 ,the language of the chalk is not hard to learn1 not nearly so hard as ,latin1 if you only want to get at the broad features of the story it has to tell2 and ,i propose that we now set to work to spell that story out together4 ,we all know that if we burn chalk1 the result is quicklime4 ,chalk1 in fact1 is a compound of carbonic acid gas and lime2 and when you make it very hot1 the carbonic acid flies away and the lime is left4 ,by this method of procedure we see the lime1 but we do not see the carbonic acid4 ,if1 on the other hand1 you were to powder a little chalk and drop it into a good deal of strong vinegar1 there would be a great bubbling and fizzing1 and1 finally1 a clear liquid1 in which no sign of chalk would appear4 ,here you see the carbonic acid in the bubbles2 the lime1 dissolved in the vinegar1 vanishes from sight4 ,there are a great many other ways of showing that chalk is essentially nothing but carbonic acid and quicklime4 ,chemists enunciate the result of all the experiments which prove this1 by stating that chalk is almost wholly composed of carbonate of lime4 ,it is desirable for us to start from the knowledge of this fact1 though it may not seem to help us very far toward what we seek4 ,for carbonate of lime is a widely-spread substance1 and is met with under very various conditions4 ,all sorts of limestones are composed of more or less pure carbonate of lime4 ,the crust which is often deposited by waters which have drained through limestone rocks1 in the form of what are called stalagmites and stalactites1 is carbonate of lime4 ,or1 to take a more familiar example1 the fur on the inside of a tea-kettle is carbonate of lime2 and1 for anything chemistry tells us to the contrary1 the chalk might be a kind of gigantic fur upon the bottom of the earth-kettle1 which is kept pretty hot below4 ,let us try another method of making the chalk tell us its own history4 ,to the unassisted eye chalk looks simply like a very loose and open kind of stone4 ,but it is possible to grind a slice of chalk down so thin that you can see through it--until it is thin enough1 in fact1 to be examined with any magnifying power that may be thought desirable4 ,a thin slice of the fur of a kettle might be made in the same way4 ,if it were examined microscopically1 it would show itself to be a more or less distinctly laminated mineral substance1 and nothing more4 ,but the slice of chalk presents a totally different appearance when placed under the microscope4 ,the general mass of it is made up of very minute granules2 but1 imbedded in this matrix1 are innumerable bodies1 some smaller and some larger1 but1 on a rough average1 not more than a hundredth of an inch in diameter1 having a well-defined shape and structure4 ,a cubic inch of some specimens of chalk may contain hundreds of thousands of these bodies1 compacted together with incalculable millions of the granules4 ,illustration3 ,,chalk4 7,magnified nearly #ajj diameters47 ,the examination of a transparent slice gives a good notion of the manner in which the components of the chalk are arranged1 and of their relative proportions4 ,but1 by rubbing up some chalk with a brush in water and then pouring off the milky fluid1 so as to obtain sediments of different degrees of fineness1 the granules and the minute rounded bodies may be pretty well separated from one another1 and submitted to microscopic examination1 either as opaque or as transparent objects4 ,by combining the views obtained in these various methods1 each of the rounded bodies may be proved to be a beautifully-constructed calcareous fabric1 made up of a number of chambers1 communicating freely with one another4 ,the chambered bodies are of various forms4 ,one of the commonest is something like a badly-grown raspberry1 being formed of a number of nearly globular chambers of different sizes congregated together4 ,it is called ,globigerina1 and some specimens of chalk consist of little else than ,globigerin and granules4 ,illustration3 ,,globigerina4 ,let us fix our attention upon the ,globigerina4 ,it is the spoor of the game we are tracking4 ,if we can learn what it is and what are the conditions of its existence1 we shall see our way to the origin and past history of the chalk4 ,a suggestion which may naturally enough present itself is1 that these curious bodies are the result of some process of aggregation which has taken place in the carbonate of lime2 that1 just as in winter1 the rime on our windows simulates the most delicate and elegantly arborescent foliage--proving that the mere mineral matter may1 under certain conditions1 assume the outward form of organic bodies--so this mineral substance1 carbonate of lime1 hidden away in the bowels of the earth1 has taken the shape of these chambered bodies4 ,i am not raising a merely fanciful and unreal objection4 ,very learned men1 in former days1 have even entertained the notion that all the formed things found in rocks are of this nature2 and if no such conception is at present held to be admissible1 it is because long and varied experience has now shown that mineral matter never does assume the form and structure we find in fossils4 ,if anyone were to try to persuade you that an oyster-shell 7which is also chiefly composed of carbonate of lime7 had crystallized out of sea-water1 ,i suppose you would laugh at the absurdity4 ,your laughter would be justified by the fact that all experience tends to show that oyster-shells are formed by the agency of oysters1 and in no other way4 ,and if there were no better reasons1 we should be justified1 on like grounds1 in believing that ,globigerina is not the product of anything but vital activity4 ,happily1 however1 better evidence in proof of the organic nature of the ,globigerin than that of analogy is forthcoming4 ,it so happens that calcareous skeletons1 exactly similar to the ,globigerin of the chalk1 are being formed1 at the present moment1 by minute living creatures1 which flourish in multitudes1 literally more numerous than the sands of the sea-shore1 over a large extent of that part of the earth's surface which is covered by the ocean4 ,the history of the discovery of these living ,globigerin1 and of the part which they play in rock-building1 is singular enough4 ,it is a discovery which1 like others of no less scientific importance1 has arisen1 incidentally1 out of work devoted to very different and exceedingly practical interests4 ,when men first took to the sea1 they speedily learned to look out for shoals and rocks2 and the more the burthen of their ships increased1 the more imperatively necessary it became for sailors to ascertain with precision the depth of the waters they traversed4 ,out of this necessity grew the use of the lead and sounding-line2 and1 ultimately1 marine-surveying1 which is the recording of the form of coasts and of the depth of the sea1 as ascertained by the sounding-lead1 upon charts4 ,at the same time1 it became desirable to ascertain and to indicate the nature of the sea-bottom1 since this circumstance greatly affects its goodness as holding ground for anchors4 ,some ingenious tar1 whose name deserves a better fate than the oblivion into which it has fallen1 attained this object by arming the bottom of the lead with a lump of grease1 to which more or less of the sand or mud1 or broken shells1 as the case might be1 adhered1 and was brought to the surface4 ,but1 however well adapted such an apparatus might be for rough nautical purposes1 scientific accuracy could not be expected from the armed lead1 and to remedy its defects 7especially when applied to sounding in great depths7 ,lieutenant ,brooke1 of the ,american ,navy1 some years ago invented a most ingenious machine1 by which a considerable portion of the superficial layer of the sea-bottom can be scooped out and brought up1 from any depth to which the lead descends4 ,in #ahec1 ,lieutenant ,brooke obtained mud from the bottom of the ,north ,atlantic1 between ,newfoundland and the ,azores1 at a depth of more than ten thousand feet1 or two miles1 by the help of this sounding apparatus4 ,the specimens were sent for examination to ,ehrenberg of ,berlin1 and to ,bailey of ,west ,point1 and those able microscopists found that this deep-sea mud was almost entirely composed of the skeletons of living organisms--the greater proportion of these being just like the ,globigerin already known to occur in chalk4 ,thus far1 the work had been carried on simply in the interests of science1 but ,lieutenant ,brooke's method of sounding acquired a high commercial value1 when the enterprise of laying down the telegraph-cable between this country and the ,united ,states was undertaken4 ,for it became a matter of immense importance to know1 not only the depth of the sea over the whole line1 along which the cable was to be laid1 but the exact nature of the bottom1 so as to guard against chances of cutting or fraying the strands of that costly rope4 ,the ,admiralty consequently ordered ,captain ,dayman1 an old friend and shipmate of mine1 to ascertain the depth over the whole line of the cable1 and to bring back specimens of the bottom4 ,in former days1 such a command as this might have sounded very much like one of the impossible things which the young prince in the ,fairy ,tales is ordered to do before he can obtain the hand of the princess4 ,however1 in the months of ,june and ,july1 #aheg1 my friend performed the task assigned to him with great expedition and precision1 without1 so far as ,i know1 having met with any reward of that kind4 ,the specimens of ,atlantic mud which he procured were sent to me to be examined and reported upon4 ,the result of all these operations is1 that we know the contours and the nature of the surface-soil covered by the ,north ,atlantic1 for a distance of seventeen hundred miles from east to west1 as well as we know that of any part of the dry land4 ,it is a prodigious plain--one of the widest and most even plains in the world4 ,if the sea were drained off1 you might drive a wagon all the way from ,valentia1 on the west coast of ,ireland1 to ,trinity ,bay in ,newfoundland4 ,and1 except upon one sharp incline about two hundred miles from ,valentia1 ,i am not quite sure that it would even be necessary to put the skid on1 so gentle are the ascents and descents upon that long route4 ,from ,valentia the road would lie down-hill for about two hundred miles to the point at which the bottom is now covered by seventeen hundred fathoms of sea-water4 ,then would come the central plain1 more than a thousand miles wide1 the inequalities of the surface of which would be hardly perceptible1 though the depth of water upon it now varies from ten thousand to fifteen thousand feet2 and there are places in which ,mont ,blanc might be sunk without showing its peak above water4 ,beyond this1 the ascent on the ,american side commences1 and gradually leads1 for about three hundred miles1 to the ,newfoundland shore4 ,almost the whole of the bottom of this central plain 7which extends for many hundred miles in a north and south direction7 is covered by a fine mud1 which1 when brought to the surface1 dries into a grayish white friable substance4 ,you can write with this on a black-board1 if you are so inclined2 and1 to the eye1 it is quite like very soft1 grayish chalk4 ,examined chemically1 it proves to be composed almost wholly of carbonate of lime2 and if you make a section of it1 in the same way as that of the piece of chalk was made1 and view it with the microscope1 it presents innumerable ,globigerin embedded in a granular matrix4 ,thus this deep-sea mud is substantially chalk4 ,i say substantially1 because there are a good many minor differences2 but as these have no bearing on the question immediately before us--which is the nature of the ,globigerin of the chalk--it is unnecessary to speak of them4 ,globigerin of every size1 from the smallest to the largest1 are associated together in the ,atlantic mud1 and the chambers of many are filled by a soft animal matter4 ,this soft substance is1 in fact1 the remains of the creature to which the ,globigerina shell1 or rather skeleton1 owes its existence--and which is an animal of the simplest imaginable description4 ,it is1 in fact1 a mere particle of living jelly1 without defined parts of any kind--without a mouth1 nerves1 muscles1 or distinct organs1 and only manifesting its vitality to ordinary observation by thrusting out and retracting from all parts of its surface long filamentous processes1 which serve for arms and legs4 ,yet this amorphous particle1 devoid of everything which1 in the higher animals1 we call organs1 is capable of feeding1 growing1 and multiplying2 of separating from the ocean the small proportion of carbonate of lime which is dissolved in sea-water2 and of building up that substance into a skeleton for itself1 according to a pattern which can be imitated by no other known agency4 ,the notion that animals can live and flourish in the sea1 at the vast depths from which apparently living ,giobigerin have been brought up1 does not agree very well with our usual conceptions respecting the conditions of animal life2 and it is not so absolutely impossible as it might at first sight appear to be1 that the ,globigerin of the ,atlantic sea-bottom do not live and die where they are found4 ,illustration3 ,,diatom ,,ooze ,,dredged ,,from ,a ,,depth ,,of #aiej ,,feet4 7,magnified nearly #cjj diameters47 ,as ,i have mentioned1 the soundings from the great ,atlantic plain are almost entirely made up of ,globigerin1 with the granules which have been mentioned1 and some few other calcareous shells2 but a small percentage of the chalky mud--perhaps at most some five per cent of it--is of a different nature1 and consists of shells and skeletons composed of silex1 or pure flint4 ,these siliceous bodies belong partly to the lowly vegetable organisms which are called ,diatomace1 and partly to the minute and extremely simple animals1 termed ,radiolaria4 ,it is quite certain that these creatures do not live at the bottom of the ocean1 but at its surface--where they may be obtained in prodigious numbers by the use of a properly constructed net4 ,hence it follows that these siliceous organisms1 though they are not heavier than the lightest dust1 must have fallen1 in some cases1 through fifteen thousand feet of water1 before they reached their final resting-place on the ocean floor4 ,and1 considering how large a surface these bodies expose in proportion to their weight1 it is probable that they occupy a great length of time in making their burial journey from the surface of the ,atlantic to the bottom4 ,illustration3 ,,radiolaria4 7a4 ,natural size4 b4 ,one-third natural size47 ,but if the ,radiolaria and ,diatoms are thus rained upon the bottom of the sea1 from the superficial layer of its waters in which they pass their lives1 it is obviously possible that the ,globigerin may be similarly derived2 and if they were so1 it would be much more easy to understand how they obtain their supply of food than it is at present4 ,nevertheless1 the positive and negative evidence all points the other way4 ,the skeletons of the full-grown1 deep-sea ,globigerin are so remarkably solid and heavy in proportion to their surface as to seem little fitted for floating2 and1 as a matter of fact1 they are not to be found along with the ,diatoms and ,radiolaria1 in the uppermost stratum of the open ocean4 ,it has been observed1 again1 that the abundance of ,globigerin1 in proportion to other organisms of like kind1 increases with the depth of the sea2 and that deep-water ,globigerin are larger than those which live in the shallower parts of the sea2 and such facts negative the supposition that these organisms have been swept by currents from the shallows into the deeps of the ,atlantic4 ,it therefore seems to be hardly doubtful that these wonderful creatures live and die at the depths in which they are found4#a ,footnote #a3 ,during the cruise of ,h4,m4,s4 ,bull-dog1 commanded by ,sir ,leopold ,m',clintock1 in #ahfj1 living star-fish were brought up1 clinging to the lowest part of the sounding-line1 from a depth of #abfj fathoms1 midway between ,cape ,farewell1 in ,greenland1 and the ,rockall banks4 ,dr4 ,wallich ascertained that the sea-bottom at this point consisted of the ordinary ,globigerina ooze1 and that the stomachs of the star-fishes were full of ,globigerin4 ,this discovery removes all objections to the existence of living ,globigerin at great depths1 which are based upon the supposed difficulty of maintaining animal life under such conditions2 and it throws the burden of proof upon those who object to the supposition that the ,globigerin live and die where they are found4 ,however1 the important points for us are1 that the living ,globigerin are exclusively marine animals1 the skeletons of which abound at the bottom of deep seas2 and that there is not a shadow of reason for believing that the habits of the ,globigerin of the chalk differed from those of the existing species4 ,but if this be true1 there is no escaping the conclusion that the chalk itself is the dried mud of an ancient deep sea4 ,in working over the soundings collected by ,captain ,dayman1 ,i was surprised to find that many of what ,i have called the granules of that mud were not1 as one might have been tempted to think at first1 the mere powder and waste of ,globigerin1 but that they had a definite form and size4 ,i termed these bodies coccoliths and doubted their organic nature4 ,dr4 ,wallich verified my observation1 and added the interesting discovery that1 not unfrequently1 bodies similar to these coccoliths were aggregated together into spheroids1 which he termed coccospheres4 ,so far as we knew1 these bodies1 the nature of which is extremely puzzling and problematical1 were peculiar to the ,atlantic soundings4 ,but1 a few years ago1 ,mr4 ,sorby1 in making a careful examination of the chalk by means of thin sections and otherwise1 observed1 as ,ehrenberg had done before him1 that much of its granular basis possesses a definite form4 ,comparing these formed particles with those in the ,atlantic soundings1 he found the two to be identical2 and thus proved that the chalk1 like the soundings1 contains these mysterious coccoliths and coccospheres4 ,here was a further and a most interesting confirmation1 from internal evidence1 of the essential identity of the chalk with modern deep-sea mud4 ,globigerin1 coccoliths1 and coccospheres are found as the chief constituents of both1 and testify to the general similarity of the conditions under which both have been formed4#b ,footnote #b3 ,i have recently traced out the development of the coccoliths from a diameter of #a_/gjjjth of an inch up to their largest size 7which is about #a_/afjjth71 and no longer doubt that they are produced by independent organisms1 which1 like the ,globigerin1 live and die at the bottom of the sea4 ,the evidence furnished by the hewing1 facing1 and superposition of the stones of the ,pyramids1 that these structures were built by men1 has no greater weight than the evidence that the chalk was built by ,globigerin2 and the belief that those ancient pyramid-builders were terrestrial and air-breathing creatures like ourselves1 is not better based than the conviction that the chalk-makers lived in the sea4 ,but as our belief in the building of the ,pyramids by men is not only grounded on the internal evidence afforded by these structures1 but gathers strength from multitudinous collateral proofs1 and is clinched by the total absence of any reason for a contrary belief2 so the evidence drawn from the ,globigerin that the chalk is an ancient sea-bottom1 is fortified by innumerable independent lines of evidence2 and our belief in the truth of the conclusion to which all positive testimony tends1 receives the like negative justification from the fact that no other hypothesis has a shadow of foundation4 ,it may be worth while briefly to consider a few of these collateral proofs that the chalk was deposited at the bottom of the sea4 ,the great mass of the chalk is composed1 as we have seen1 of the skeletons of ,globigerin1 and other simple organisms1 imbedded in granular matter4 ,here and there1 however1 this hardened mud of the ancient sea reveals the remains of higher animals which have lived and died1 and left their hard parts in the mud1 just as the oysters die and leave their shells behind them1 in the mud of the present seas4 ,illustration3 ,,upper ,,silurian ,,corals ,,and ,,crustaceans4 ,there are1 at the present day1 certain groups of animals which are never found in fresh waters1 being unable to live anywhere but in the sea4 ,such are the corals2 those corallines which are called ,polyzoa2 those creatures which fabricate the lamp-shells1 and are called ,brachiopoda2 the pearly ,nautilus1 and all animals allied to it2 and all the forms of sea-urchins and star-fishes4 ,not only are all these creatures confined to salt water at the present day1 but1 so far as our records of the past go1 the conditions of their existence have been the same3 hence1 their occurrence in any deposit is as strong evidence as can be obtained1 that that deposit was formed in the sea4 ,now the remains of animals of all the kinds which have been enumerated occur in the chalk1 in greater or less abundance2 while not one of those forms of shell-fish which are characteristic of fresh water has yet been observed in it4 ,when we consider that the remains of more than three thousand distinct species of aquatic animals have been discovered among the fossils of the chalk1 that the great majority of them are of such forms as are now met with only in the sea1 and that there is no reason to believe that any one of them inhabited fresh water--the collateral evidence that the chalk represents an ancient sea-bottom acquires as great force as the proof derived from the nature of the chalk itself4 ,i think you will now allow that ,i did not overstate my case when ,i asserted that we have as strong grounds for believing that all the vast area of dry land at present occupied by the chalk was once at the bottom of the sea1 as we have for any matter of history whatever2 while there is no justification for any other belief4 ,illustration3 ,,cretaceous ,,nautilus4 ,no less certain is it that the time during which the countries we now call southeast ,england1 ,france1 ,germany1 ,poland1 ,russia1 ,egypt1 ,arabia1 ,syria1 were more or less completely covered by a deep sea1 was of considerable duration4 ,we have already seen that the chalk is1 in places1 more than a thousand feet thick4 ,i think you will agree with me that it must have taken some time for the skeletons of the animalcules of a hundredth of an inch in diameter to heap up such a mass as that4 ,i have said that throughout the thickness of the chalk the remains of other animals are scattered4 ,these remains are often in the most exquisite state of preservation4 ,the valves of the shell-fishes are commonly adherent2 the long spines of some of the sea-urchins1 which would be detached by the smallest jar1 often remain in their places4 ,in a word1 it is certain that these animals have lived and died when the place which they now occupy was the surface of as much of the chalk as had then been deposited2 and that each has been covered up by the layer of ,globigerina mud1 upon which the creatures imbedded a little higher up have1 in like manner1 lived and died4 ,but some of these remains prove the existence of reptiles of vast size in the chalk sea4 ,these lived their time1 and had their ancestors and descendants1 which assuredly implies time1 reptiles being of slow growth4 ,there is more curious evidence1 again1 that the process of covering up1 or1 in other words1 the deposit of ,globigerina skeletons1 did not go on very fast4 ,it is demonstrable that an animal of the cretaceous sea might die1 that its skeleton might lie uncovered upon the sea-bottom long enough to lose all its outward coverings and appendages by putrefaction2 and that1 after this had happened1 another animal might attach itself to the dead and naked skeleton1 might grow to maturity1 and might itself die before the calcareous mud had buried the whole4 ,cases of this kind are admirably described by ,sir ,charles ,lyell4 ,he speaks of the frequency with which geologists find in the chalk a fossilized sea-urchin to which is attached the lower valve of a ,crania4 ,this is a kind of shell-fish1 with a shell composed of two pieces1 of which1 as in the oyster1 one is fixed and the other free4 ,the upper valve is almost invariably wanting1 though occasionally found in a perfect state of preservation in the white chalk at some distance4 ,in this case1 we see clearly that the sea-urchin first lived from youth to age1 then died and lost its spines1 which were carried away4 ,then the young ,crania adhered to the bared shell1 grew and perished in its turn2 after which1 the upper valve was separated from the lower1 before the ,echinus became enveloped in chalky mud4 ,a specimen in the ,museum of ,practical ,geology1 in ,london1 still further prolongs the period which must have elapsed between the death of the sea-urchin and its burial by the ,globigering4 ,for the outward face of the valve of a ,crania1 which is attached to a sea-urchin 7,micrastor71 is itself overrun by an incrusting coralline1 which spreads thence over more or less of the surface of the sea-urchin4 ,it follows that1 after the upper valve of the ,crania fell off1 the surface of the attached valve must have remained exposed long enough to allow of the growth of the whole coralline1 since corallines do not live imbedded in the mud4 ,the progress of knowledge may1 one day1 enable us to deduce from such facts as these the maximum rate at which the chalk can have accumulated1 and thus to arrive at the minimum duration of the chalk period4 ,suppose that the valve of the ,crania upon which a coralline has fixed itself in the way just described is so attached to the sea-urchin that no part of it is more than an inch above the face upon which the sea-urchin rests4 ,then1 as the coralline could not have fixed itself if the ,crania had been covered up with chalk-mud1 and could not have lived had itself been so covered1 it follows1 that an inch of chalk mud could not have accumulated within the time between the death and decay of the soft parts of the sea-urchin and the growth of the coralline to the full size which it has attained4 ,if the decay of the soft parts of the sea-urchin2 the attachment1 growth to maturity1 and decay of the ,crania2 and the subsequent attachment and growth of the coralline1 took a year 7which is a low estimate enough71 the accumulation of the inch of chalk must have taken more than a year3 and the deposit of a thousand feet of chalk must1 consequently1 have taken more than twelve thousand years4 ,the foundation of all this calculation is1 of course1 a knowledge of the length of time the ,crania and the coralline needed to attain their full size2 and1 on this head1 precise knowledge is at present wanting4 ,but there are circumstances which tend to show that nothing like an inch of chalk has accumulated during the life of a ,crania2 and1 on any probable estimate of the length of that life1 the chalk period must have had a much longer duration than that thus roughly assigned to it4 ,thus1 not only is it certain that the chalk is the mud of an ancient sea-bottom2 but it is no less certain that the chalk sea existed during an extremely long period1 though we may not be prepared to give a precise estimate of the length of that period in years4 ,the relative duration is clear1 though the absolute duration may not be definable4 ,the attempt to affix any precise date to the period at which the chalk sea began or ended its existence1 is baffled by difficulties of the same kind4 ,but the relative age of the cretaceous epoch may be determined with as great ease and certainty as the long duration of that epoch4 ,you will have heard of the interesting discoveries recently made1 in various parts of ,western ,europe1 of flint implements1 obviously worked into shape by human hands1 under circumstances which show conclusively that man is a very ancient denizen of these regions4 ,it has been proved that the old populations of ,europe1 whose existence has been revealed to us in this way1 consisted of savages1 such as the ,esquimaux are now2 that1 in the country which is now ,france1 they hunted the reindeer1 and were familiar with the ways of the mammoth and the bison4 ,the physical geography of ,france was in those days different from what it is now--the river ,somme1 for instance1 having cut its bed a hundred feet deeper between that time and this2 and it is probable that the climate was more like that of ,canada or ,siberia than that of ,western ,europe4 ,the existence of these people is forgotten even in the traditions of the oldest historical nations4 ,the name and fame of them had utterly vanished until a few years back2 and the amount of physical change which has been effected since their day renders it more than probable that1 venerable as are some of the historical nations1 the workers of the chipped flints of ,hoxne or of ,amiens are to them1 as they are to us1 in point of antiquity4 ,but1 if we assign to these hoar relics of long-vanished generations of men the greatest age that can possibly be claimed for them1 they are not older than the drift1 or boulder clay1 which1 in comparison with the chalk1 is but a very juvenile deposit4 ,you need go no further than your own seaboard for evidence of this fact4 ,at one of the most charming spots on the coast of ,norfolk1 ,cromer1 you will see the boulder clay forming a vast mass1 which lies upon the chalk1 and must consequently have come into existence after it4 ,huge boulders of chalk are1 in fact1 included in the clay1 and have evidently been brought to the position they now occupy by the same agency as that which has planted blocks of syenite from ,norway side by side with them4 ,the chalk1 then1 is certainly older than the boulder clay4 ,if you ask how much1 ,i will again take you no further than the same spot upon your own coasts for evidence4 ,i have spoken of the boulder clay and drift as resting upon the chalk4 ,that is not strictly true4 ,interposed between the chalk and the drift is a comparatively insignificant layer1 containing vegetable matter4 ,but that layer tells a wonderful history4 ,it is full of stumps of trees standing as they grew4 ,fir-trees are there with their cones1 and hazel-bushes with their nuts2 there stand the stools of oak and yew trees1 beeches and alders4 ,hence this stratum is appropriately called the forest-bed4 ,it is obvious that the chalk must have been upheaved and converted into dry land before the timber trees could grow upon it4 ,as the bolls of some of these trees are from two to three feet in diameter1 it is no less clear that the dry land thus formed remained in the same condition for long ages4 ,and not only do the remains of stately oaks and well-grown firs testify to the duration of this condition of things1 but additional evidence to the same effect is afforded by the abundant remains of elephants1 rhinoceroses1 hippopotamuses1 and other great wild beasts1 which it has yielded to the zealous search of such men as the ,rev4 ,mr4 ,gunn4 ,when you look at such a collection as he has formed1 and bethink you that these elephantine bones did veritably carry their owners about1 and these great grinders crunch1 in the dark woods of which the forest-bed is now the only trace1 it is impossible not to feel that they are as good evidence of the lapse of time as the annual rings of the tree-stumps4 ,thus there is a writing upon the wall of cliffs at ,cromer1 and whoso runs may read it4 ,it tells us1 with an authority which cannot be impeached1 that the ancient sea-bed of the chalk sea was raised up1 and remained dry land1 until it was covered with forest1 stocked with the great game whose spoils have rejoiced your geologists4 ,how long it remained in that condition cannot be said2 but the whirligig of time brought its revenges in those days as in these4 ,that dry land1 with the bones and teeth of generations of long-lived elephants1 hidden away among the gnarled roots and dry leaves of its ancient trees1 sank gradually to the bottom of the icy sea1 which covered it with huge masses of drift and boulder clay4 ,sea-beasts1 such as the walrus1 now restricted to the extreme north1 paddled about where birds had twittered among the topmost twigs of the fir-trees4 ,how long this state of things endured we know not1 but at length it came to an end4 ,the upheaved glacial mud hardened into the soil of modern ,norfolk4 ,forests grew once more1 the wolf and the beaver replaced the reindeer and the elephant2 and at length what we call the history of ,england dawned4 ,thus you have1 within the limits of your own county1 proof that the chalk can justly claim a very much greater antiquity than even the oldest physical traces of mankind4 ,but we may go further and demonstrate1 by evidence of the same authority as that which testifies to the existence of the father of men1 that the chalk is vastly older than ,adam himself4 ,the ,book of ,genesis informs us that ,adam1 immediately upon his creation1 and before the appearance of ,eve1 was placed in the garden of ,eden4 ,the problem of the geographical position of ,eden has greatly vexed the spirits of the learned in such matters1 but there is one point respecting which1 so far as ,i know1 no commentator has ever raised a doubt4 ,this is1 that of the four rivers which are said to run out of it1 ,euphrates and ,hiddekel are identical with the rivers now known by the names of ,euphrates and ,tigris4 ,but the whole country in which these mighty rivers take their origin1 and through which they run1 is composed of rocks which are either of the same age as the chalk1 or of later date4 ,so that the chalk must not only have been formed1 but1 after its formation1 the time required for the deposit of these later rocks1 and for their upheaval into dry land1 must have elapsed1 before the smallest brook which feeds the swift stream of the great river1 the river of ,babylon1 began to flow4 99 99 99 99 99 ,thus1 evidence which cannot be rebutted1 and which need not be strengthened1 though if time permitted ,i might indefinitely increase its quantity1 compels you to believe that the earth1 from the time of the chalk to the present day1 has been the theatre of a series of changes as vast in their amount as they were slow in their progress4 ,the area on which we stand has been first sea and then land1 for at least four alternations2 and has remained in each of these conditions for a period of great length4 ,nor have these wonderful metamorphoses of sea into land1 and of land into sea1 been confined to one corner of ,england4 ,during the chalk period1 or cretaceous epoch1 not one of the present great physical features of the globe was in existence4 ,our great mountain ranges1 ,pyrenees1 ,alps1 ,himalayas1 ,andes1 have all been upheaved since the chalk was deposited1 and the cretaceous sea flowed over the sites of ,sinai and ,ararat4 ,all this is certain1 because rocks of cretaceous or still later date have shared in the elevatory movements which gave rise to these mountain chains2 and may be found perched up1 in some cases1 many thousand feet high upon their flanks4 ,and evidence of equal cogency demonstrates that1 though in ,norfolk the forest-bed rests directly upon the chalk1 yet it does so1 not because the period at which the forest grew immediately followed that at which the chalk was formed1 but because an immense lapse of time1 represented elsewhere by thousands of feet of rock1 is not indicated at ,cromer4 ,i must ask you to believe that there is no less conclusive proof that a still more prolonged succession of similar changes occurred before the chalk was deposited4 ,nor have we any reason to think that the first term in the series of these changes is known4 ,the oldest sea-beds preserved to us are sands1 and mud1 and pebbles1 the wear and tear of rocks which were formed in still older oceans4 ,but1 great as is the magnitude of these physical changes of the world1 they have been accompanied by a no less striking series of modifications in its living inhabitants4 ,all the great classes of animals1 beasts of the field1 fowls of the air1 creeping things1 and things which dwell in the waters1 flourished upon the globe long ages before the chalk was deposited4 ,very few1 however1 if any1 of these ancient forms of animal life were identical with those which now live4 ,certainly not one of the higher animals was of the same species as any of those now in existence4 ,the beasts of the field1 in the days before the chalk1 were not our beasts of the field1 nor the fowls of the air such as those which the eye of man has seen flying1 unless his antiquity dates infinitely further back than we at present surmise4 ,if we could be carried back into those times1 we should be as one suddenly set down in ,australia before it was colonized4 ,we should see mammals1 birds1 reptiles1 fishes1 insects1 snails1 and the like1 clearly recognizable as such1 and yet not one of them would be just the same as those with which we are familiar1 and many would be extremely different4 ,from that time to the present1 the population of the world has undergone slow and gradual1 but incessant1 changes4 ,there has been no grand catastrophe--no destroyer has swept away the forms of life of one period1 and replaced them by a totally new creation2 but one species has vanished and another has taken its place2 creatures of one type of structure have diminished1 those of another have increased1 as time has passed on4 ,and thus1 while the differences between the living creatures of the time before the chalk and those of the present day appear startling1 if placed side by side1 we are led from one to the other by the most gradual progress1 if we follow the course of ,nature through the whole series of those relics of her operations which she has left behind4 ,illustration3 ,,skeleton ,,of ,,the ,,pterodactyl4 ,and it is by the population of the chalk sea that the ancient and the modern inhabitants of the world are most completely connected4 ,the groups which are dying out flourish1 side by side1 with the groups which are now the dominant forms of life4 ,thus the chalk contains remains of those flying and swimming reptiles1 the pterodactyl1 the ichthyosaurus1 and the plesiosaurus1 which are found in no later deposits1 but abounded in preceding ages4 ,the chambered shells called ammonites and belemnites1 which are so characteristic of the period preceding the cretaceous1 in like manner die with it4 ,illustration3 ,,the ,,skeleton ,,of ,,the ,,ichthyosaurus4 ,illustration3 ,,the ,,skeleton ,,of ,,the ,,plesiosaurus4 ,illustration3 ,,ammonites4 ,but1 among these fading remainders of a previous state of things1 are some very modern forms of life1 looking like ,yankee peddlers among a tribe of red ,indians4 ,crocodiles of modern type appear2 bony fishes1 many of them very similar to existing species1 almost supplant the forms of fish which predominate in more ancient seas2 and many kinds of living shell-fish first become known to us in the chalk4 ,the vegetation acquires a modern aspect4 ,a few living animals are not even distinguishable as species from those which existed at that remote epoch4 ,the ,globigerina of the present day1 for example1 is not different specifically from that of the chalk2 and the same may be said of many other ,foraminifera4 ,i think it probable that critical and unprejudiced examination will show that more than one species of much higher animals have had a similar longevity2 but the only example which ,i can at present give confidently is the snake's-head lamp-shell 7,terebratulina caput serpentis71 which lives in our ,english seas and abounded 7as ,terebratulina striata of authors7 in the chalk4 ,illustration3 ,,belemnites4 ,illustration3 ,,terebratulina4 ,the longest line of human ancestry must hide its diminished head before the pedigree of this insignificant shell-fish4 ,we ,englishmen are proud to have an ancestor who was present at the ,battle of ,hastings4 ,the ancestors of ,terebratulina caput serpentis may have been present at a battle of ,ichthyosauria in that part of the sea which1 when the chalk was forming1 flowed over the site of ,hastings4 ,while all around has changed1 this ,terebratulina has peacefully propagated its species from generation to generation1 and stands to this day as a living testimony to the continuity of the present with the past history of the globe4 99 99 99 99 99 ,up to this moment ,i have stated1 so far as ,i know1 nothing but well-authenticated facts1 and the immediate conclusions which they force upon the mind4 ,but the mind is so constituted that it does not willingly rest in facts and immediate causes1 but seeks always after a knowledge of the remoter links in the chain of causation4 ,taking the many changes of any given spot of the earth's surface1 from sea to land1 and from land to sea1 as an established fact1 we cannot refrain from asking ourselves how these changes have occurred4 ,and when we have explained them--as they must be explained--by the alternate slow movements of elevation and depression which have affected the crusts of the earth1 we go still further back1 and ask1 ,why these movements8 ,i am not certain that any one can give you a satisfactory answer to that question4 ,assuredly ,i cannot4 ,all that can be said for certain is1 that such movements are part of the ordinary course of nature1 inasmuch as they are going on at the present time4 ,direct proof may be given1 that some parts of the land of the northern hemisphere are at this moment insensibly rising and others insensibly sinking2 and there is indirect but perfectly satisfactory proof1 that an enormous area now covered by the ,pacific has been deepened thousands of feet since the present inhabitants of that sea came into existence4 ,thus there is not a shadow of a reason for believing that the physical changes of the globe1 in past times1 have been effected by other than natural causes4 ,is there any more reason for believing that the concomitant modifications in the forms of the living inhabitants of the globe have been brought about in any other ways8 ,before attempting to answer this question1 let us try to form a distinct mental picture of what has happened in some special case4 ,the crocodiles are animals which1 as a group1 have a very vast antiquity4 ,they abounded ages before the chalk was deposited2 they throng the rivers in warm climates at the present day4 ,there is a difference in the form of the joints of the backbone1 and in some minor particulars1 between the crocodiles of the present epoch and those which lived before the chalk2 but1 in the cretaceous epoch1 as ,i have already mentioned1 the crocodiles had assumed the modern type of structure4 ,notwithstanding this1 the crocodiles of the chalk are not identically the same as those which lived in the times called older tertiary1 which succeeded the cretaceous epoch2 and the crocodiles of the older tertiaries are not identical with those of the newer tertiaries1 nor are these identical with existing forms4 ,i leave open the question whether particular species may have lived on from epoch to epoch4 ,but each epoch has had its peculiar crocodiles2 though all1 since the chalk1 have belonged to the modern type1 and differ simply in their proportions and in such structural particulars as are discernible only to trained eyes4 ,how is the existence of this long succession of different species of crocodiles to be accounted for8 ,only two suppositions seem to be open to us--either each species of crocodile has been specially created1 or it has arisen out of some pre-existing form by the operation of natural causes4 ,choose your hypothesis2 ,i have chosen mine4 ,i can find no warranty for believing in the distinct creation of a score of successive species of crocodiles in the course of countless ages of time4 ,science gives no countenance to such a wild fancy2 nor can even the perverse ingenuity of a commentator pretend to discover this sense1 in the simple words in which the writer of ,genesis records the proceeding of the fifth and sixth days of the ,creation4 ,on the other hand1 ,i see no good reason for doubting the necessary alternative1 that all these varied species have been evolved from pre-existing crocodilian forms by the operation of causes as completely a part of the common order of nature as those which have effected the changes of the inorganic world4 ,few will venture to affirm that the reasoning which applies to crocodiles loses its force among other animals or among plants4 ,if one series of species has come into existence by the operation of natural causes1 it seems folly to deny that all may have arisen in the same way4 99 99 99 99 99 ,a small beginning has led us to a great ending4 ,if ,i were to put the bit of chalk with which we started into the hot but obscure flame of burning hydrogen1 it would presently shine like the sun4 ,it seems to me that this physical metamorphosis is no false image of what has been the result of our subjecting it to a jet of fervent1 though nowise brilliant1 thought to-night4 ,it has become luminous1 and its clear rays1 penetrating the abyss of the remote past1 have brought within our ken some stages of the evolution of the earth4 ,and in the shifting without haste1 but without rest of the land and sea1 as in the endless variation of the forms assumed by living beings1 we have observed nothing but the natural product of the forces originally possessed by the substance of the universe4 ,illustration ,a ,,bit ,,of ,,sponge 7,written on ,scotland47 7,,from ,,glimpses ,,of ,,nature47 ,,by ,a4 ,,wilson4 ,illustration ,this morning1 despite the promise of rain over-night1 has broken with all the signs and symptoms of a bright ,july day4 ,the ,firth is bathed in sunlight1 and the wavelets at full tide are kissing the strand1 making a soft musical ripple as they retire1 and as the pebbles run down the sandy slope on the retreat of the waves4 ,beyond the farthest contact of the tide is a line of seaweed dried and desiccated1 mixed up with which1 in confusing array1 are masses of shells1 and such olla podrida of the sea4 ,tossed up at our very feet is a dried fragment of sponge1 which doubtless the unkind waves tore from its rocky bed4 ,it is not a large portion of sponge this1 but its structure is nevertheless to be fairly made out1 and some reminiscences of its history gleaned1 for the sake of occupying the by no means bad half-hour before breakfast4 ,what is a sponge8 is a question which you may well ask as a necessary preliminary to the understanding of its personality4 ,illustration3 ,a ,,sponge ,,attached ,,to ,,its ,,rocky ,,bed4 ,the questionings of childhood and the questionings of science run in precisely similar grooves4 ,what is it8 and ,how does it live8 and ,where does it come from8 are equally the inquiries of childhood1 and of the deepest philosophy which seeks to determine the whole history of life4 ,this morning1 we cannot do better than follow in the footsteps of the child1 and to the question1 ,what is a sponge8 ,i fancy science will be able to return a direct answer4 ,first of all1 we may note that a sponge1 as we know it in common life1 is the horny skeleton or framework which was made by1 and which supported1 the living parts4 ,these living parts consist of minute masses of that living jelly to which the name of protoplasm has been applied4 ,this1 in truth1 is the universal matter of life4 ,it is the one substance with which life everywhere is associated1 and as we see it simply in the sponge1 so also we behold it 7only in more complex guise7 in the man4 ,now1 the living parts of this dried cast-away sponge were found both in its interior and on its surface4 ,they lined the canals that everywhere permeate the sponge-substance1 and microscopic examination has told us a great deal about their nature4 ,illustration3 ,,fig4 #a4 ,,development ,,of ,a ,,sponge 7,olynthus74 #a4 ,the egg4 #b1 #c1 and #d4 ,the process of egg-division4 #e and #f4 ,the gastrula-stage4 #g4 ,the perfect sponge4 ,for1 whether found in the canals of the sponge themselves1 or embedded in the sponge-substance1 the living sponge-particles are represented each by a semi-independent mass of protoplasm4 ,so that the first view ,i would have you take of the sponge as a living mass1 is1 that it is a colony and not a single unit4 ,it is composed1 in other words1 of aggregated masses of living particles1 which bud out one from the other1 and manufacture the supporting skeleton we know as the sponge of commerce itself4 ,under the microscope1 these living sponge-units appear in various guises and shapes4 ,some of them are formless1 and1 as to shape1 ever-altering masses1 resembling that familiar animalcule of our pools we know as the ,amoeba4 ,these members of the sponge-colony form the bulk of the population4 ,they are embedded in the sponge substance2 they wander about through the meshes of the sponge2 they seize food and flourish and grow2 and they probably also give origin to the eggs from which new sponges are in due course produced4 ,more characteristic however1 are certain units of this living sponge-colony which live in the lining membrane of the canals4 ,in point of fact1 a sponge is a kind of ,venice1 a certain proportion of whose inhabitants1 like those of the famous ,queen of the ,adriatic herself1 live on the banks of the waterways4 ,just as in ,venice we find the provisions for the denizens of the city brought to the inhabitants by the canals1 so from the water1 which1 as we shall see1 is perpetually circulating through a sponge1 the members of the sponge-colony receive their food4 ,look1 again1 at the sponge-fragment which lies before us4 ,you perceive half a dozen large holes or so1 each opening on a little eminence1 as it were4 ,these apertures1 bear in mind1 we call oscula4 ,they are the exits of the sponge-domain4 ,but a close inspection of a sponge shows that it is riddled with finer and smaller apertures4 ,these latter are the pores1 and they form the entrances to the sponge-domain4 ,on the banks of the canal you may see growing plentifully in summer time a green sponge1 which is the common fresh-water species4 ,now1 if you drop a living specimen of this species into a bowl of water1 and put some powdered indigo into the water1 you may note how the currents are perpetually being swept in by the pores and out by the oscula4 ,in every living sponge this perpetual and unceasing circulation of water proceeds4 ,this is the sole evidence the unassisted sight receives of the vitality of the sponge-colony1 and the importance of this circulation in aiding life in these depths1 to be fairly carried out cannot readily be over-estimated4 ,illustration3 ,,where ,,sponges ,,grow4 ,let us now see how this circulation is maintained4 ,microscopically regarded1 we see here and there1 in the sides of the sponge-passages1 little chambers and recesses which remind one of the passing-places in a narrow canal4 ,lining these chambers1 we see living sponge-units of a type different from the shapeless specks we noted to occur in the meshes of the sponge substance itself4 ,the units of the recesses each consist of a living particle1 whose free extremity is raised into a kind of collar1 from which projects a lash-like filament known as a flagellum4 ,this lash is in constant movement4 ,it waves to and fro in the water1 and the collection of lashes we see in any one chamber acts as a veritable brush1 which by its movement not only sweeps water in by the pores1 but sends it onwards through the sponge1 and in due time sends it out by the bigger holes1 or oscula4 ,this constant circulation in the sponge discharges more than one important function4 ,for1 as already noted1 it serves the purpose of nutrition1 in that the particles on which sponge-life is supported are swept into the colony4 ,again1 the fresh currents of water carry with them the oxygen gas which is a necessity of sponge existence1 as of human life2 while1 thirdly1 waste matters1 inevitably alike in sponge and in man as the result of living1 are swept out of the colony1 and discharged into the sea beyond4 ,our bit of sponge has thus grown from a mere dry fragment into a living reality4 ,it is a community in which already1 low as it is1 the work of life has come to be discharged by distinct and fairly specialized beings4 ,the era of new sponge-life is inaugurated by means of egg-development1 although there exists another fashion 7that of gemmules or buds7 whereby out of the parental substance young sponges are produced4 ,a sponge-egg develops1 as do all eggs1 in a definite cycle4 ,it undergoes division 7,fig4 #a72 its one cell becomes many2 and its many cells arrange themselves first of all into a cup-like form 7#e1 #f and #g71 which may remain in this shape if the sponge is a simple one1 or become developed into the more complex shape of the sponges we know4 ,in every museum you may see specimens of a beautiful vase-like structure seemingly made of spun-glass4 ,this is a flinty sponge1 the ,venus flower-basket1 whose presence in the sponge family redeems it from the charge that it contains no things of beauty whatever4 ,so1 too1 the rocks are full of fossil-sponges1 many of quaint form4 ,our piece of sponge1 as we may understand1 has yet other bits of history attached to it4444 ,meanwhile1 think over the sponge and its ways1 and learn from it that out of the dry things of life1 science weaves many a fairy tale4 ,illustration ,,the ,,greatest ,,sea-,,wave ,,ever ,,known 7,,from ,,light ,,science ,,in ,,leisure ,,hours47 ,,by ,r4,a4 ,,proctor4 ,illustration ,august #acth1 #ahfh1 one of the most terrible calamities which has ever visited a people befell the unfortunate inhabitants of ,peru4 ,in that land earthquakes are nearly as common as rain storms are with us2 and shocks by which whole cities are changed into a heap of ruins are by no means infrequent4 ,yet even in ,peru1 the land of earthquakes1 as ,humboldt has termed it1 no such catastrophe as that of ,august1 #ahfh1 had occurred within the memory of man4 ,it was not one city which was laid in ruins1 but a whole empire4 ,those who perished were counted by tens of thousands1 while the property destroyed by the earthquake was valued at millions of pounds sterling4 ,although so many months have passed since this terrible calamity took place1 scientific men have been busily engaged1 until quite recently1 in endeavoring to ascertain the real significance of the various events which were observed during and after the occurrence of the earthquake4 ,the geographers of ,germany have taken a special interest in interpreting the evidence afforded by this great manifestation of ,nature's powers4 ,two papers have been written recently on the great earthquake of ,august #acth1 #ahfh--one by ,professor von ,hochsteter1 the other by ,herr von ,tschudi1 which present an interesting account of the various effects1 by land and by sea1 which resulted from the tremendous upheaving force to which the western flanks of the ,peruvian ,andes were subjected on that day4 ,the effects on land1 although surprising and terrible1 only differ in degree from those which have been observed in other earthquakes4 ,but the progress of the great sea-wave which was generated by the upheaval of the ,peruvian shores and propagated over the whole of the ,pacific ,ocean differs altogether from any earthquake phenomena before observed4 ,other earthquakes have indeed been followed by oceanic disturbances2 but these have been accompanied by terrestrial motions1 so as to suggest the idea that they had been caused by the motion of the sea-bottom or of the neighboring land4 ,in no instance has it ever before been known that a well-marked wave of enormous proportions should have been propagated over the largest ocean tract on our globe by an earth-shock whose direct action was limited to a relatively small region1 and that region not situated in the centre1 but on one side of the wide area traversed by the wave4 ,we propose to give a brief sketch of the history of this enormous sea-wave4 ,in the first place1 however1 it may be well to remind the reader of a few of the more prominent features of the great shock to which this wave owed its origin4 ,it was at ,arequipa1 at the foot of the lofty volcanic mountain ,misti1 that the most terrible effects of the great earthquake were experienced4 ,within historic times ,misti has poured forth no lava streams1 but that the volcano is not extinct is clearly evidenced by the fact that in #aedb an enormous mass of dust and ashes was vomited forth from its crater4 ,on ,august #acth4 #ahfh1 ,misti showed no signs of being disturbed4 ,so far as the volcanic neighbor was concerned1 the forty-four thousand inhabitants of ,arequipa had no reason to anticipate the catastrophe which presently befell them4 ,at five minutes past five an earthquake shock was experienced1 which1 though severe1 seems to have worked little mischief4 ,half a minute later1 however1 a terrible noise was heard beneath the earth2 a second shock more violent than the first was felt1 and then began a swaying motion1 gradually increasing in intensity4 ,in the-course of the first minute this motion had become so violent that the inhabitants ran in terror out of their houses into the streets and squares4 ,in the next two minutes the swaying movement had so increased that the more lightly built houses were cast to the ground1 and the flying people could scarcely keep their feet4 ,and now1 says ,von ,tschudi1 there followed during two or three minutes a terrible scene4 ,the swaying motion which had hitherto prevailed changed into fierce vertical upheaval4 ,the subterranean roaring increased in the most terrifying manner2 then were heard the heart-piercing shrieks of the wretched people1 the bursting of walls1 the crashing fall of houses and churches1 while over all rolled thick clouds of a yellowish-black dust1 which1 had they been poured forth many minutes longer1 would have suffocated thousands4 ,although the shocks had lasted but a few minutes1 the whole town was destroyed4 ,not one building remained uninjured1 and there were few which did not lie in shapeless heaps of ruins4 ,at ,tacna and ,arica the earth-shock was less severe1 but strange and terrible phenomena followed it4 ,at the former place a circumstance occurred the cause and nature of which yet remain a mystery4 ,about three hours after the earthquake--in other words1 at about eight o'clock in the evening--an intensely brilliant light made its appearance above the neighboring mountains4 ,it lasted for fully half an hour1 and has been ascribed to the eruption of some as yet unknown volcano4 ,at ,arica the sea-wave produced even more destructive effects than had been caused by the earthquake4 ,about twenty minutes after the first earth-shock the sea was seen to retire1 as if about to leave the shores wholly dry2 but presently its waters returned with tremendous force4 ,a mighty wave1 whose length seemed immeasurable1 was seen advancing like a dark wall upon the unfortunate town1 a large part of which was overwhelmed by it4 ,two ships1 the ,peruvian corvette ,america1 and the ,united ,states double-ender ,wateree1 were carried nearly half a mile to the north of ,arica beyond the railroad which runs to ,tacna1 and there left stranded high and dry4 ,this enormous wave was considered by the ,english vice-consul at ,arica to have been fully fifty feet in height4 ,at ,chala three such waves swept in after the first shocks of earthquake4 ,they overflowed nearly the whole of the town1 the sea passing more than half a mile beyond its usual limits4 ,at ,islay and ,iquique similar phenomena were manifested4 ,at the former town the lava flowed in no less than five times1 and each time with greater force4 ,afterward the motion gradually diminished1 but even an hour and a half after the commencement of this strange disturbance the waves still ran forty feet above the ordinary level4 ,at ,iquique the people beheld the inrushing wave while it was still a great way off4 ,a dark blue mass of water some fifty feet in height was seen sweeping in upon the town with inconceivable rapidity4 ,an island lying before the harbor was completely submerged by the great wave1 which still came rushing on black with the mud and slime it had swept from the sea-bottom4 ,those who witnessed its progress from the upper balconies of their houses1 and presently saw its black mass rushing close beneath their feet1 looked on their safety as a miracle4 ,many buildings were indeed washed away1 and in the low-lying parts of the town there was a terrible loss of life4 ,after passing far inland1 the wave slowly returned sea-ward1 and1 strangely enough1 the sea1 which elsewhere heaved and tossed for hours after the first great wave had swept over it1 here came soon to rest4 ,at ,callao a yet more singular instance was afforded of the effect which circumstances may have upon the motion of the sea after a great earthquake has disturbed it4 ,in former earthquakes ,callao has suffered terribly from the effects of the great sea-wave4 ,in fact1 on two occasions the whole town has been destroyed1 and nearly all its inhabitants have been drowned1 through the inrush of precisely such waves as flowed into the ports of ,arica and ,chala4 ,but upon this occasion the centre of subterranean disturbance must have been so situated that either the wave was diverted from ,callao1 or1 more probably1 two waves reached ,callao from different sources and at different times1 so that the two undulations partly counteracted each other4 ,certain it is that1 although the water retreated strangely from the coast near ,callao1 insomuch that a wide tract of the sea-bottom was uncovered1 there was no inrushing wave comparable with those described above4 ,the sea afterward rose and fell in an irregular manner1 a circumstance confirming the supposition that the disturbance was caused by two distinct oscillations4 ,six hours after the occurrence of the earth-shock the double oscillations seemed for a while to have worked themselves into unison1 for at this time three considerable waves rolled in upon the town4 ,but clearly these waves must not be compared with those which in other instances had made their appearance within half an hour of the earth-throes4 ,there is little reason to doubt that if the separate oscillations had re-enforced each other earlier1 ,callao would have been completely destroyed4 ,as it was1 a considerable amount of mischief was effected2 but the motion of the sea presently became irregular again1 and so continued until the morning of ,august #adth1 when it began to ebb with some regularity4 ,but during the #adth there were occasional renewals of the irregular motion1 and several days elapsed before the regular ebb and flow of the sea were resumed4 ,such were among the phenomena presented in the region where the earthquake itself was felt4 ,it will be seen at once that within this region1 or rather along that portion of the sea-coast which falls within the central region of disturbance1 the true character of the sea-wave generated by the earthquake could not be recognized4 ,if a rock fall from a lofty cliff into a comparatively shallow sea1 the water around the place where the rock has fallen is disturbed in an irregular manner4 ,the sea seems at one place to leap up and down2 elsewhere one wave seems to beat against another1 and the sharpest eye can detect no law in the motion of the seething waters4 ,but presently1 outside the scene of disturbance1 a circular wave is seen to form1 and if the motion of this wave be watched it is seen to present the most striking contrast with the turmoil and confusion at its centre4 ,it sweeps onward and outward in a regular undulation4 ,gradually it loses its circular figure 7unless the sea-bottom happens to be unusually level71 showing that although its motion is everywhere regular1 it is not everywhere equally swift4 ,a wave of this sort1 though incomparably vaster1 swept swiftly away on every side from the scene of the great earthquake near the ,peruvian ,andes4 ,it has been calculated that the width of this wave varied from one million to five million feet1 or1 roughly1 from two hundred to one thousand miles1 while1 when in mid-,pacific1 the length of the wave1 measured along its summit in a widely-curved path from one side to another of the great ocean1 cannot have been less than eight thousand miles4 ,illustration3 ,,over ,a ,,large ,,portion ,,of ,,its ,,course ,,its ,,passage ,,was ,,unnoted4 ,we cannot tell how deep-seated was the centre of subterranean action2 but there can be no doubt it was very deep indeed1 because otherwise the shock felt in towns separated from each other by hundreds of miles could not have been so nearly contemporaneous4 ,therefore the portion of the earth's crust upheaved must have been enormous1 for the length of the region where the direct effects of the earthquake were perceived is estimated by ,professor von ,hochsteter at no less than two hundred and forty miles4 ,the breadth of the region is unknown1 because the slope of the ,andes on one side and the ocean on the other concealed the motion of the earth's crust4 ,the great ocean-wave swept1 as we have said1 in all directions around the scene of the earth-throe4 ,over a large part of its course its passage was unnoted1 because in the open sea the effects even of so vast an undulation could not be perceived4 ,a ship would slowly rise as the crest of the great wave passed under her1 and then as slowly sink again4 ,this may seem strange1 at first sight1 when it is remembered that in reality the great sea-wave we are considering swept at the rate of three or four hundred sea-miles an hour over the larger part of the ,pacific4 ,but when the true character of ocean-waves is understood1 when it is remembered that there is no transference of the water itself at this enormous rate1 but simply a transmission of motion 7precisely as when in a high wind waves sweep rapidly over a cornfield1 while yet each cornstalk remains fixed in the ground71 it will be seen that the effects of the great sea-wave could only be perceived near the shore4 ,even there1 as we shall presently see1 there was much to convey the impression that the land itself was rising and falling rather than that the deep was moved4 ,but among the hundreds of ships which were sailing upon the ,pacific when its length and breadth were traversed by the great sea-wave1 there was not one in which any unusual motion was perceived4 ,in somewhat less than three hours after the occurrence of the earthquake the ocean-wave inundated the port of ,coquimbo1 on the ,chilean seaboard1 some eight hundred miles from ,arica4 ,an hour or so later it had reached ,constitucion1 four hundred and fifty miles farther south2 and here for some three hours the sea rose and fell with strange violence4 ,farther south1 along the shore of ,chile1 even to the island of ,chiloe1 the shore-wave travelled1 though with continually diminishing force1 owing1 doubtless1 to the resistance which the irregularities of the shore opposed to its progress4 ,the northerly shore-wave seems to have been more considerable2 and a moment's study of a chart of the two ,americas will show that this circumstance is highly significant4 ,when we remember that the principal effects of the land-shock were experienced within that angle which the ,peruvian ,andes form with the long north-and-south line of the ,chilean and ,bolivian ,andes1 we see at once that1 had the centre of the subterranean action been near the scene where the most destructive effects were perceived1 no sea-wave1 or but a small one1 could have been sent toward the shores of ,north ,america4 ,the projecting shores of northern ,peru and ,ecuador could not have failed to divert the sea-wave toward the west2 and though a reflected wave might have reached ,california1 it would only have been after a considerable interval of time1 and with dimensions much less than those of the sea-wave which travelled southward4 ,when we see that1 on the contrary1 a wave of even greater proportions travelled toward the shores of ,north ,america1 we seem forced to the conclusion that the centre of the subterranean action must have been so far to the west that the sea-wave generated by it had a free course to the shores of ,california4 ,be this as it may1 there can be no doubt that the wave which swept the shores of ,southern ,california1 rising upward of sixty feet above the ordinary sea-level1 was absolutely the most imposing of all the indirect effects of the great earthquake4 ,when we consider that even in ,san ,pedro ,bay1 fully five thousand miles from the centre of disturbance1 a wave twice the height of an ordinary house rolled in with unspeakable violence only a few hours after the occurrence of the earth-throe1 we are most strikingly impressed with the tremendous energy of the earth's movement4 ,turning to the open ocean1 let us track the great wave on its course past the multitudinous islands which dot the surface of the ,pacific4 ,the inhabitants of the ,sandwich ,islands1 which lie about six thousand three hundred miles from ,arica1 might have imagined themselves safe from any effects which could be produced by an earthquake taking place so far away from them4 ,but on the night between ,august #acth and #adth1 the sea around this island group rose in a surprising manner1 insomuch that many thought the islands were sinking1 and would shortly subside altogether beneath the waves4 ,some of the smaller islands1 indeed1 were for a time completely submerged4 ,before long1 however1 the sea fell again1 and as it did so the observers found it impossible to resist the impression that the islands were rising bodily out of the water4 ,for no less than three days this strange oscillation of the sea continued to be experienced1 the most remarkable ebbs and floods being noticed at ,honolulu1 on the island of ,woahoo4 ,but the sea-wave swept onward far beyond these islands4 ,at ,yokohama1 in ,japan1 more than ten thousand five hundred miles from ,arica1 an enormous wave poured in on ,august #adth1 but at what hour we have no satisfactory record4 ,so far as distance is concerned1 this wave affords most surprising evidence of the stupendous nature of the disturbance to which the waters of the ,pacific ,ocean had been subjected4 ,the whole circumference of the earth is but twenty-five thousand miles1 so that this wave had travelled over a distance considerably greater than two-fifths of the earth's circumference4 ,a distance which the swiftest of our ships could not traverse in less than six or seven weeks had been swept over by this enormous undulation in the course of a few hours4 ,more complete details reach us from the ,southern ,pacific4 ,shortly before midnight the ,marquesas ,isles and the low-lying ,tuamotu group were visited by the great wave1 and some of these islands were completely submerged by it4 ,the lonely ,opara ,isle1 where the steamers which run between ,panama and ,new ,zealand have their coaling station1 was visited at about half-past eleven in the evening by a billow which swept away a portion of the coal depot4 ,afterward great waves came rolling in at intervals of about twenty minutes1 and several days elapsed before the sea resumed its ordinary ebb and flow4 ,it was not until about half-past two on the morning of ,august #adth that the ,samoa ,isles 7sometimes called the ,navigator ,islands7 were visited by the great wave4 ,the watchmen startled the inhabitants from their sleep by the cry that the sea was about to overwhelm them2 and already1 when the terrified people rushed from their houses1 the sea was found to have risen far above the highest water-mark4 ,but it presently began to sink again1 and then commenced a series of oscillations1 which lasted for several days1 and were of a very remarkable nature4 ,once in every quarter of an hour the sea rose and fell1 but it was noticed that it rose twice as rapidly as it sank4 ,this peculiarity is well worth remarking4 ,the eminent physicist ,mallet speaks thus 7we follow ,lyell's quotation7 about the waves which traverse an open sea3 ,the great sea-wave1 advancing at the rate of several miles in a minute1 consists1 in the deep ocean1 of a long1 low swell of enormous volume1 having an equal slope before and behind1 and that so gentle that it might pass under a ship without being noticed4 ,but when it reaches the edge of soundings1 its front slope becomes short and steep1 while its rear slope is long and gentle4 ,on the shores visited by such a wave1 the sea would appear to rise more rapidly than it sank4 ,we have seen that this happened on the shores of the ,samoa group1 and therefore the way in which the sea rose and fell on the days following the great earthquake gave significant evidence of the nature of the sea-bottom in the neighborhood of these islands4 ,as the change of the great wave's figure could not have been quickly communicated1 we may conclude with certainty that the ,samoan ,islands are the summits of lofty mountains1 whose sloping sides extend far toward the east4 ,this conclusion affords interesting evidence of the necessity of observing even the seemingly trifling details of important phenomena4 ,the wave which visited the ,new ,zealand ,isles was altogether different in character1 affording a noteworthy illustration of another remark of ,mallet's4 ,he says that where the sea-bottom slopes in such a way that there is water of some depth close inshore1 the great wave may roll in and do little damage2 and we have seen that so it happened in the case of the ,samoan ,islands4 ,but he adds that1 where the shore is shelving there will be first a retreat of the water1 and then the wave will break upon the beach and roll far in upon the land4 ,this is precisely what happened when the great wave reached the eastern shores of ,new ,zealand1 which are known to shelve down to very shallow water1 continuing far away to sea toward the east4 ,at about half-past three on the morning of ,august #adth the water began to retreat in a singular manner from the port of ,littleton1 on the eastern shores of the southernmost of the ,new ,zealand ,islands4 ,at length the whole port was left entirely dry1 and so remained for about twenty minutes4 ,then the water was seen returning like a wall of foam ten or twelve feet in height1 which rushed with a tremendous noise upon the port and town4 ,toward five o'clock the water again retired1 very slowly as before1 not reaching its lowest ebb until six4 ,an hour later a second huge wave inundated the port4 ,four times the sea retired and returned with great power at intervals of about two hours4 ,afterward the oscillation of the water was less considerable1 but it had not wholly ceased until ,august #agth1 and only on the #ahth did the regular ebb and flow of the tide recommence4 ,around the ,samoa group the water rose and fell once in every fifteen minutes1 while on the shores of ,new ,zealand each oscillation lasted no less than two hours4 ,doubtless the different depths of water1 the irregular conformation of the island groups1 and other like circumstances1 were principally concerned in producing these singular variations4 ,yet they do not seem fully sufficient to account for so wide a range of difference4 ,possibly a cause yet unnoticed may have had something to do with the peculiarity4 ,in waves of such enormous extent it would be quite impossible to determine whether the course of the wave motion was directed full upon a line of shore or more or less obliquely4 ,it is clear that in the former case the waves would seem to follow each other more swiftly than in the latter1 even though there were no difference in their velocity4 ,far on beyond the shores of ,new ,zealand the great wave coursed1 reaching at length the coast of ,australia4 ,at dawn of ,august #adth ,moreton ,bay was visited by five well-marked waves4 ,at ,newcastle1 on the ,hunter ,river1 the sea rose and fell several times in a remarkable manner1 the oscillatory motion commencing at half-past six in the morning4 ,but the most significant evidence of the extent to which the sea-wave travelled in this direction was afforded at ,port ,fairy1 ,belfast1 ,south ,victoria4 ,here the oscillation of the water was distinctly perceived at midday on ,august #adth2 and yet1 to reach this point1 the sea-wave must not only have travelled on a circuitous course nearly equal in length to half the circumference of the earth1 but must have passed through ,bass's ,straits1 between ,australia and ,van ,diemen's ,land1 and so have lost a considerable portion of its force and dimensions4 ,when we remember that had not the effects of the earth-shock on the water been limited by the shores of ,south ,america1 a wave of disturbance equal in extent to that which travelled westward would have swept toward the east1 we see that the force of the shock was sufficient to have disturbed the waters of an ocean covering the whole surface of the earth4 ,for the sea-waves which reached ,yokohama in one direction and ,port ,fairy in another had each traversed a distance nearly equal to half the earth's circumference2 so that if the surface of the earth were all sea1 waves setting out in opposite directions from the centre of disturbance would have met each other at the antipodes of their starting-point4 ,it is impossible to contemplate the effects which followed the great earthquake--the passage of a sea-wave of enormous volume over fully one third of the earth's surface1 and the force with which1 on the farthermost limits of its range1 the wave rolled in upon shores more than ten thousand miles from its starting-place--without feeling that those geologists are right who deny that the subterranean forces of the earth are diminishing in intensity4 ,it may be difficult1 perhaps1 to look on the effects which are ascribed to ancient earth-throes without imagining for a while that the power of modern earthquakes is altogether less4 ,but when we consider fairly the share which time had in those ancient processes of change1 when we see that while mountain ranges were being upheaved or valleys depressed to their present position1 race after race1 and type after type appeared on the earth1 and lived out the long lives which belong to races and to types1 we are recalled to the remembrance of the great work which the earth's subterranean forces are still engaged upon4 ,even now continents are being slowly depressed or upheaved2 even now mountain ranges are being raised to a new level1 tablelands are in process of formation1 and great valleys are being gradually scooped out4 ,it may need an occasional outburst1 such as the earthquake of ,august1 #ahfh1 to remind us that great forces are at work beneath the earth's surface4 ,but1 in reality1 the signs of change have long been noted4 ,old shore-lines shift their place1 old soundings vary2 the sea advances in one place and retires in another2 on every side ,nature's plastic hand is at work modelling and remodelling the earth1 in order that it may always be a fit abode for those who are to dwell upon it4 ,illustration ,,the ,,phosphorescent ,,sea 7,,from ,,studies ,,of ,,animated ,,nature47 ,,by ,w4,s4 ,,dallas4 ,illustration ,it is not merely on land that this phenomenon of phosphorescence is to be seen in living forms4 ,among marine animals1 indeed1 it is a phenomenon much more general1 much more splendid1 and1 we may add1 much more familiar to those who live on our coasts4 ,there must be many in the ,british ,isles who have never had the opportunity of seeing the light of the glow-worm1 but there can be few of those who have frequented in summer any part of our coasts1 who have never seen that beautiful greenish light which is then so often visible1 especially on our southern shores1 when the water is disturbed by the blade of an oar or the prow of a boat or ship4 ,in some cases1 even on our own shores1 the phenomenon is much more brilliant1 every rippling wave being crested with a line of the same peculiar light1 and in warmer seas exhibitions of this kind are much more common4 ,it is now known that this light is due to a minute living form1 to which we will afterward return4 ,but before going on to speak in some detail of the organisms to which the phosphorescence of the sea is due1 it will be as well to mention that the kind of phosphorescence just spoken of is only one mode in which the phenomenon is exhibited on the ocean4 ,though sometimes the light is shown in continuous lines whenever the surface is disturbed1 at other times1 and1 according to ,m4 de ,quatrefages1 more commonly1 the light appears only in minute sparks1 which1 however numerous1 never coalesce4 ,in the little channel known as the ,sund de ,chausez1 he writes1 ,i have seen on a dark night each stroke of the oar kindle1 as it were1 myriads of stars1 and the wake of the craft appeared in a manner besprinkled with diamonds4 ,when such is the case the phosphorescence is due to various minute animals1 especially crustaceans2 that is1 creatures which1 microscopically small as they are1 are yet constructed more or less on the type of the lobster or cray-fish4 ,at other times1 again1 the phosphorescence is still more partial4 ,great domes of pale gold with long streamers1 to use the eloquent words of ,professor ,martin ,duncan1 move slowly along in endless succession2 small silvery disks swim1 now enlarging and now contracting1 and here and there a green or bluish gleam marks the course of a tiny1 but rapidly rising and sinking globe4 ,hour after hour the procession passes by1 and the fishermen hauling in their nets from the midst drag out liquid light1 and the soft sea jellies1 crushed and torn piecemeal1 shine in every clinging particle4 ,the night grows dark1 the wind rises and is cold1 and the tide changes2 so does the luminosity of the sea4 ,the pale spectres below the surface sink deeper1 and are lost to sight1 but the increasing waves are tinged here and there with green and white1 and often along a line1 where the fresh water is mixing with the salt in an estuary1 there is a brightness so intense that boats and shores are visible4444 ,but if such sights are to be seen on the surface1 what must not be the phosphorescence of the depths6 ,every sea-pen is glorious in its light1 in fact1 nearly every eight-armed ,alcyonarian is thus resplendent1 and the social ,pyrosoma1 bulky and a free swimmer1 glows like a bar of hot metal with a white and green radiance4 ,such accounts are enough to indicate how varied and how general a phenomenon is the phosphorescence of the sea4 ,to take notice of one tithe of the points of interest summed up in the paragraph just quoted would occupy many pages1 and we must therefore confine the attention to a few of the most interesting facts relating to marine phosphorescence4 ,we will return to that form of marine luminosity to which we first referred3 what is known as the general or diffused phosphorescence of the sea4 ,from this mode of describing it the reader must not infer that the surface of the ocean is ever to be seen all aglow in one sheet of continuous light4 ,so far1 at least1 as was ever observed by ,m4 de ,quatrefages1 who studied this phenomenon carefully and during long periods on the coasts of ,brittany and elsewhere1 no light was visible when the surface of the sea was perfectly still4 ,on the other hand1 when the sea exhibits in a high degree the phenomenon of diffused phosphorescence no disturbance can be too slight to cause the water to shine with that peculiar characteristic gleam4 ,drop but a grain of sand upon its surface1 and you will see a point of light marking the spot where it falls1 and from that point as a centre a number of increasing wavelets1 each clearly defined by a line of light1 will spread out in circles all around4 ,the cause of this diffused phosphorescence was long the subject of curiosity1 and was long unknown1 but more than a hundred years ago 7in #agfd7 the light was stated by ,m4 ,kigaut to proceed from a minute and very lowly organism1 now known as ,noctiluca miliaris2 and subsequent researches have confirmed this opinion4 ,this ,noctiluca is a spherical form of not more than one-fiftieth of an inch in size1 with a slight depression or indentation at one point1 marking the position of a mouth leading to a short digestive cavity1 and having close beside it a filament1 by means of which it probably moves about4 ,the sphere is filled with protoplasm1 in which there is a nucleus and one or more gaps1 or vacuoles4 ,such is nearly all the structure that can be discerned with the aid of the microscope in this simple organism4 ,nevertheless1 this lowly form is the chief cause of that diffused phosphorescence which is sometimes seen over a wide extent of the ocean4 ,how innumerable the individuals belonging to this species must therefore be1 may be left to the imagination4 ,probably the ,noctiluca is not rivalled in this respect even by miscroscopic unicellular alg which compose the red snow4 ,by filtering sea-water containing ,noctiluc its light can be concentrated1 and it has been found that a few teaspoonfuls will then yield light enough to enable one to read holding a book at the ordinary distance from the eyes--about ten inches4 ,a singular and highly remarkable case of diffused marine phosphorescence was observed by ,nordenskild during his voyage to ,greenland in #ahhc4 ,one dark night1 when the weather was calm and the sea smooth1 his vessel was steaming across a narrow inlet called the ,igaliko ,fjord1 when the sea was suddenly observed to be illumined in the rear of the vessel by a broad but sharply-defined band of light1 which had a uniform1 somewhat golden sheen1 quite unlike the ordinary bluish-green phosphorescence of the sea4 ,the latter kind of light was distinctly visible at the same time in the wake of the vessel4 ,though the steamer was going at the rate of from five to six miles an hour1 the remarkable sheet of light got nearer and nearer4 ,when quite close1 it appeared as if the vessel were sailing in a sea of fire or molten metal4 ,in the course of an hour the light passed on ahead1 and ultimately it disappeared in the remote horizon4 ,the nature of this phenomenon ,nordenskild is unable to explain2 and unfortunately he had not the opportunity of examining it with the spectroscope4 ,if we come now to consider the more partial phosphorescence of the sea1 we find that it is due to animals belonging to almost every group of marine forms--to ,echinoderms1 or creatures of the sea-urchin and star-fish type1 to ,annelid worm1 to ,medusid1 or jelly-fish1 as they are popularly called1 including the great domes and the silvery disks of the passage above quoted from ,professor ,martin ,duncan1 to ,tunicates1 among which is the ,pyrosoma1 to ,mollusks1 ,crustaceans1 and in very many cases to ,actinozoa1 or forms belonging to the type of the sea anemone and the coral polyp4 ,of these we will single out only a few for more special notice4 ,many of the ,medusid1 or jelly-fish1 possess the character of which we are speaking4 ,in some cases the phosphorescence is spontaneous among them1 but in others it is not so2 the creature requires to be irritated or stimulated in some way before it will emit the light4 ,it is spontaneous1 for example1 in the ,pelagia phosphorea1 but not in the allied ,pelagia noctiluca1 a very common form in the ,mediterranean4 ,in both of the jelly-fishes just mentioned the phosphorescence1 when displayed at all1 is on the surface of the swimming disk1 and this is most commonly the case with the whole group4 ,sometimes1 however1 the phosphorescence is specially localized4 ,in some forms1 as in ,thaumantius pilosella and other members of the same genus1 it is seen in buds at the base of tentacles given off from the margin of the swimming-bell4 ,in other cases it is situated in certain internal organs1 as in the canals which radiate from the centre to the margin of the bell1 or in the ovaries4 ,it is from this latter seat that the phosphorescence proceeds in ,oceania pilata1 the form which gives out such a light that ,ehrenberg compared it to a lamp-globe lighted by a flame4 ,the property of emitting a phosphorescent light1 sometimes spontaneously and sometimes on being stimulated1 is likewise exemplified in the ,ctenophora1 a group resembling the ,medusid in the jelly-like character of their bodies1 but more closely allied in structure to the ,actinozoa4 ,but we will pass over these cases in order to dwell more particularly on the remarkable tunicate known as ,pyrosoma1 a name indicative of its phosphorescent property1 being derived from two ,greek words signifying fire-body4 ,as shown in the illustration ,pyrosoma is not a single creature1 but is composed of a whole colony of individuals1 each of which is represented by one of the projections on the surface of the tube1 closed at one end1 which they all combine to form4 ,the free end on the exterior contains the mouth1 while there is another opening in each individual toward the interior of the tube4 ,such colonies1 which swim about by the alternate contraction and dilatation of the individuals composing them1 are pretty common in the ,mediterranean1 where they may attain the length of perhaps fourteen inches1 with a breadth of about three inches4 ,in the ocean they may reach a much greater size4 ,mr4 ,moseley1 in his ,notes of a ,naturalist on the ,challenger1 mentions a giant specimen which he once caught in the deep-sea trawl1 a specimen four feet in length and ten inches in diameter1 with walls of jelly about an inch in thickness4 ,illustration3 ,a4 ,,pyrosoma4 ,b4 ,,poniton4 7,magnified47 ,the same naturalist states that the light emitted by this compound form is the most beautiful of all kinds of phosphorescence4 ,when stimulated by a touch1 or shake1 or swirl of the water1 it gives out a globe of bluish light1 which lasts for several seconds1 as the animal drifts past several feet beneath the surface1 and then suddenly goes out4 ,he adds that on the giant specimen just referred to be wrote his name with his finger as it lay on the deck in a tub at night1 and in a few seconds he had the gratification of seeing his name come out in letters of fire4 ,among mollusks1 the best known instance of phosphorescence is in the rock-boring ,pholas1 the luminosity of which after death is mentioned by ,pliny4 ,but it is not merely after death that ,pholas becomes luminous--a phenomenon perfectly familiar even in the case of many fish1 especially the herring and mackerel4 ,it was long before the luminosity of the living animal was known1 but this is now a well-ascertained fact2 and ,panceri1 an ,italian naturalist1 recently dead1 has been able to discover in this1 as in several other marine phosphorescent forms1 the precise seat of the light-giving bodies1 which he has dissected out again and again for the sake of making experiments in connection with this subject4 ,a more beautiful example of a phosphorescent mollusk is presented by a sea-slug called ,phyllirho bucephala4 ,this is a creature of from one and a half to two inches in length1 without a shell in the adult stage1 and without even gills4 ,it breathes only by the general surface of the body4 ,it is common enough in the ,mediterranean1 but is not easy to see1 as it is almost perfectly transparent1 so that it cannot be distinguished without difficulty1 by day at least1 from the medium in which it swims4 ,by night1 however1 it is more easily discerned1 in consequence of its property of emitting light4 ,when disturbed or stimulated in any way1 it exhibits a number of luminous spots of different sizes irregularly distributed all over it1 but most thickly aggregated on the upper and under parts4 ,these phosphorescent spots1 it is found1 are not on the surface1 but for the most part represent so many large cells which form the terminations of nerves1 and are situated underneath the transparent cuticle4 ,the spots shine with exceptional brilliancy when the animal is withdrawn from the water and stimulated by a drop of ammonia4 ,among the ,annelid worms a species of ,nereis1 or sea-centipedes1 has earned by its phosphorescent property the specific name of noctiluca 7night-shining71 and the same property is very beautifully shown in ,polyno1 a near ally of the familiar sea-mouse4 ,m4 de ,quatrefages speaks with enthusiasm of the beauty of the spectacle presented by this latter form when examined under a microscope magnifying to the extent of a hundred diameters4 ,he then found1 as he did in the great majority of cases which he studied1 that the phosphorescence was confined to the motor muscles1 and was manifested solely when these were in the act of contracting1 manifested1 too1 not in continuous lines along the course of the muscles1 but in rows of brilliant points4 ,more interesting than the ,annelids1 however1 are the ,alcyonarian ,actinozoa4 ,the ,actinozoa have already been described as formed on the type of the sea-anemone and the coral polyp1 that is1 they are all animals with a radiate structure1 attached to one end1 and having their only opening at the other end1 which is surrounded by tentacles4 ,in the ,alcyonarian forms belonging to this great group these tentacles are always eight in number1 and fringed on both sides4 ,moreover1 these forms are almost without exception compound4 ,like the ,pyrosoma1 they have a common life belonging to a whole stock or colony1 as well as an individual life4 ,now1 throughout this sub-division of the ,actinozoa phosphorescence is a very general phenomenon4 ,professor ,moseley1 already quoted as a naturalist accompanying the ,challenger expedition1 informs us that all the ,alcyonarians dredged by the ,challenger in deep water were found to be brilliantly phosphorescent when brought to the surface4 ,among these ,alcyonarians are the sea-pens mentioned in the quotation above made from ,professor ,martin ,duncan4 ,each sea-pen is a colony of ,alcyonarians1 and the name is due to the singular arrangement of the individuals upon the common stem4 ,this stem is supported internally by a coral rod1 but its outer part is composed of fleshy matter belonging to the whole colony4 ,the lower portion of it is fixed in the muddy bottom of the sea1 but the upper portion is free1 and gives off a number of branches1 on which the individual polyps are seated4 ,the whole colony thus has the appearance of a highly ornamental pen4 ,there is one ,british species1 ,pennatula phosphorea1 which is found in tolerably deep water1 and is from two to four inches in length4 ,the specific name again indicates the phosphorescent quality belonging to it4 ,when irritated1 it shines brilliantly1 and the curious thing is that the phosphorescence travels gradually on from polyp to polyp1 starting from the point at which the irritation is applied4 ,if the lower part of the stem is irritated1 the phosphorescence passes gradually upwards along each pair of branches in succession2 but if the top is irritated the phosphorescence will pass in the same way downwards4 ,when both top and bottom are irritated simultaneously two luminous currents start at once1 and1 meeting in the middle1 usually become extinguished there2 but on one occasion ,panceri found that the two crossed1 and each completed its course independently of the other4 ,those of our readers who have had opportunities of making or seeing experiments with the sensitive plant 7,mimosa pudica7 will be reminded of the way in which1 when that plant is irritated1 the influence travels regularly on from pinnules to pinnules and pinnae to pinnae4 ,in all the cases mentioned the phenomenon of phosphorescence is exhibited by invertebrate animals2 but though rare1 it is not an unknown phenomenon even in living vertebrates4 ,in a genus of deep-sea fishes called ,stomias1 ,gunther mentions that a series of phosphorescent dots run along the lower side of the head1 body1 and tail4 ,several other deep-sea fishes1 locally phosphorescent1 seem to have been dredged up by the ,french ship ,talisman in its exploring cruise off the west coast of ,northern ,africa in #ahhc4 ,during the same expedition1 a number of deep-sea phosphorescent crustaceans were dredged up1 the phosphorescence being in some cases diffused over the whole body1 in other cases localized to particular areas4 ,in deep-sea forms the phenomenon is1 in fact1 so common1 as to have given rise to the theory that in the depths of the ocean1 where the light of the sun cannot penetrate1 the phosphorescence of various organisms diffuse a light which limits the domain of absolute darkness4 ,so much by way of illustration regarding the phosphorescence exhibited by animals1 terrestrial and marine2 but it ought to be noticed that there are also a few cases in which the same phenomenon is to be witnessed in plants4 ,these are not so numerous as was at one time supposed1 the property having been mistakenly ascribed to some plants not really luminous4 ,illustration3 ,a ,,phosphorescent ,,sea4 ,in some instances the mistake appears to have been due to a subjective effect produced by brilliantly colored 7red or orange7 flowers1 such as the great ,indian cress1 the orange lily1 the sunflower1 and the marigold4 ,the fact that such flowers do give out in the dusk sudden flashes of light has often been stated on the authority of a daughter of ,linnus1 subsequently backed by the assertions of various other observers4 ,but most careful observers seem to be agreed that the supposed flashes of light are in reality nothing else than a certain dazzling of the eyes4 ,in another case1 in which a moss1 ,schistostega osmundacea1 has been stated to be phosphorescent1 the effect is said to be really due to the refraction and reflection of light by minute crystals scattered over its highly cellular leaves1 and not to be produced at all where the darkness is complete4 ,among plants1 genuine phosphorescence is to be found chiefly in certain fungi1 the most remarkable of which is ,rhizomorpha subterranea1 which is sometimes to be seen ramifying over the walls of dark1 damp mines1 caverns1 or decayed towers1 and emitting at numerous points a mild phosphorescent light1 which is sometimes bright enough to allow of surrounding objects being distinguished by it4 ,the name of vegetable glow-worm has sometimes been applied to this curious growth4 ,among other phosphorescent fungi are several species of ,agaricus1 including the ,a4 olearius of ,europe1 ,a4 ,gardneri of ,brazil1 and ,a4 lampas of ,australia1 and besides the members of this genus1 ,thelaphora crulea1 which is the cause of the phosphorescent light sometimes to be seen on decaying wood--the touchwood which many boys have kept in the hope of seeing this light displayed4 ,the milky juice of a ,south ,american ,euphorbia 7,e4 phosphorea7 is stated by ,martins to be phosphorescent when gently heated4 ,but phosphorescence is evidently not so interesting and important a phenomenon in the vegetable as it is in the animal kingdom4 ,the whole phenomenon is one that gives rise to a good many questions which it is not easy to answer1 and this is especially true in the case of animal phosphorescence4 ,what is the nature of the light8 ,what are the conditions under which it is manifested8 ,what purpose does it serve in the animal economy8 ,as to the nature of the light1 the principal question is whether it is a direct consequence of the vital activity of the organism in which it is seen1 of such a nature that no further explanation can be given of it1 any more than we can explain why a muscle is contracted under the influence of a nerve-stimulus2 or whether it is due to some chemical process more or less analogous to the burning of a candle4 ,the fact of luminosity appearing to be in certain cases directly under the control of the creature in which it is found1 and the fact of its being manifested in many forms1 as ,m4 de ,quatrefages found1 only when muscular contraction was taking place1 would seem to favor the former view4 ,on the other hand1 it is against this view that the phosphorescence is often found to persist after the animal is dead1 and even in the phosphorescent organs for a considerable time after they have been extracted from the body of the animal4 ,in the glow-worm the light goes on shining for some time after the death of the insect1 and even when it has become completely extinguished it can be restored for a time by the application of a little moisture4 ,further1 both ,matteucci and ,phipson found that when the luminous substance was extracted from the insect it would keep on glowing for thirty or forty minutes4 ,in ,pholas the light is still more persistent1 and it is found that when the dead body of this mollusk is placed in honey1 it will retain for more than a year the power of emitting light when plunged in warm water4 ,the investigations of recent years have rendered it more and more probable that the light exhibited by phosphorescent organisms is due to a chemical process somewhat analogous to that which goes on in the burning of a candle4 ,this latter process is one of rapid oxidation4 ,the particles of carbon supplied by the oily matter that feeds the candle become so rapidly combined with oxygen derived from the air that a considerable amount of light1 along with heat1 is produced thereby4 ,now1 the phenomenon of phosphorescence in organic forms1 whether living or dead1 appears also to be due to a process of oxidation1 but one that goes on much more slowly than in the case of a lighted candle4 ,it is thus more closely analogous to what is observed in the element phosphorus itself1 which owes its name 7meaning light-bearer7 to the fact that when exposed to the air at ordinary temperatures it glows in the dark1 in consequence of its becoming slowly combined with oxygen4 ,at one time it was believed that the presence of oxygen was not necessary to the exhibition of phosphorescence in organic forms1 but it has now been placed beyond doubt that this is a mistake4 ,oxygen has been proved to be indispensable1 and hence we see a reason for the luminous organs in the glow-worm being so intimately connected1 as above mentioned1 with the air-tubes that ramify through the insect4 ,this fact of itself might be taken as a strong indication of the chemical nature of the process to which phosphorescence is due4 ,but the problem has been made the subject of further investigations which have thrown more light upon it4 ,it was long known that there were various inorganic bodies besides phosphorus which emitted a phosphorescent light in the dark1 at least after being exposed to the rays of the sun2 but it was not till quite recently that any organic compound was known to phosphoresce at ordinary temperatures4 ,this discovery was made by a ,polish chemist1 named ,bronislaus ,radziszewski1 who followed it up with a long series of experiments on the phosphorescence of organic compounds1 by which he was able to determine the conditions under which that phenomenon was exhibited4 ,in all the substances investigated by him in which phosphorescence was introduced he found that three conditions were essential to its production3 7#a7 that oxygen should be present2 7#b7 that there should be an alkaline reaction in the phosphorescing mixture--that is1 a reaction such as is produced on acids and vegetable coloring matters by potash1 soda1 and the other alkalies2 and 7#c7 that some kind of chemical action should take place4 ,he found1 moreover1 that among the organic compounds that could be made to phosphoresce under these conditions were nearly all the fixed and ethereal oils4 ,with reference to the phosphorescence of animals1 this observation is important1 for it has been shown in a great many cases that a fatty substance forms the main constituent in their luminous organs4 ,this has long been known to be the case in the luminous insects belonging to the ,lampyrid and ,elaterid1 as well as in the luminous centipedes2 and the researches of ,panceri1 already referred to1 on the luminous organs of many marine forms have shown that it holds good with regard to these also4 ,we may1 therefore1 conclude that substances fitted to phosphoresce under the conditions determined by the experiments of ,radziszewski are generally1 and probably universally1 present in the luminous organs of phosphorescent animals4 ,now1 what is to be said as to the occurrence of these conditions8 ,the access of oxygen is in all cases easy to account for1 but it must also be shown how the alkaline reaction is to be produced4 ,we need not expect to find in animal organisms potash1 soda1 ammonia1 and the other common alkalies2 but it was established by experiment that the alkaline organic compounds cholin and neurin1 which are present in animal tissues1 would also serve to bring about the phenomenon of phosphorescence in the substances on which the experiments were made4 ,accordingly1 it seems fair to conclude that when all these conditions for the production of phosphorescence in a chemical laboratory are present in animal organisms1 the phenomenon1 when observed in these1 is exactly of the same nature as that which is produced artificially4 ,by that it is meant that animal phosphorescence is attended1 like the artificial phenomenon1 by a slow chemical action1 or in other words1 that the phosphorescent light is due to a gradual process of oxidation4 ,one curious circumstance has been discovered which lends still further probability to this explanation4 ,it was mentioned above that among phosphorescent plants there are several species of ,agaricus4 ,now1 from one species of this genus1 though not indeed one of the phosphorescent species 7from ,a4 muscarius7 there has been extracted a principle called amanitia1 which is found to be identical with cholin4 ,in the light of the results derived from the investigations just referred to it is reasonable to draw the conclusion that1 if sought for1 this principle would likewise be found in the phosphorescent species in which the other conditions of phosphorescence are also present4 ,on this theory of the production of the phenomenon now under consideration1 the effect of shaking or of vital action in giving rise to or intensifying the exhibition of the light is accounted for by the fact that by these means fresh supplies of oxygen are brought into contact with the phosphorescent substance4 ,the effect of ammonia on the light emitted by the sea-slug ,phyllirho bucephala1 is also fully explained1 ammonia being one of those alkaline substances which are so directly favorable to the exhibition of the phenomenon4 ,nor is it difficult to account for the control which in some cases insects appear to have over the luminosity of the phosphorescent organs1 exhibiting and withdrawing the light at will4 ,it is not necessary to suppose that this is an immediate effect1 a conversion of nerve force into light1 and a withdrawal of that force4 ,the action of the creature's will may be merely in maintaining or destroying the conditions under which the light is manifested4 ,it may1 for example1 have the power of withdrawing the supply of oxygen1 and this supposition receives some countenance from the observation cited from ,kirby and ,spence on the two captured glow-worms1 one of which withdrew its light1 while the other kept it shining1 but while doing so had the posterior extremity of the abdomen in constant motion4 ,but the animal may also have the power in another way of affecting the chemical conditions of the phenomenon4 ,it may1 for example1 have the power of increasing or diminishing by some nervous influence the supply of the necessary alkaline ingredient4 ,but if animal phosphorescence is really due to a process of slow oxidation1 there is one singular circumstance to be noted in connection with it4 ,oxidation is a process that is normally accompanied by the development of heat4 ,even where no light is produced an increase of temperature regularly takes place when substances are oxidized4 ,we ought1 then1 to expect such a rise of temperature when light is emitted by the phosphorescent organs of animals4 ,but the most careful observations have shown that nothing of the kind can be detected4 ,it was with a view to test this that ,panceri dissected out the luminous organs of so many specimens of ,pholas4 ,he selected this mollusk because it was so abundant in the neighborhood of ,naples1 where1 his experiments were made2 and in making his experiments he made use of a thermopile1 an apparatus by which1 with the aid of electricity1 much smaller quantities of heat can be indicated than by means of the most delicate thermometer4 ,the organs remained luminous long after they were extracted1 but no rise in temperature whatever could be found to accompany the luminosity4 ,many experiments upon different animals were made with similar negative results by means of the thermometer4 ,the only explanation of this that can be given is probably to be found in the fact that the chemical process ascertained to go on in the phosphorescence of organic compounds on which experiments were made in the laboratory is an extremely slow one4 ,the so-called phosphorescence of most inorganic bodies is one of a totally different nature from that exhibited in organic forms4 ,the diamond shines for a time in the dark after it has been exposed to the sun2 so do pieces of quartz when rubbed together1 and powdered fluor-spar when heated shines with considerable brilliancy4 ,various artificial compounds1 such as sulphide of calcium 7,canton's phosphorus1 as it is called from the discoverer71 sulphate of barium 7,bologna stone1 or ,bologna phosphorus71 sulphide of strontium1 etc41 after being illuminated by the rays of the sun1 give out in the dark a beautiful phosphorescence1 green1 blue1 violet1 orange1 red1 according to circumstances4 ,the luminous paint which has recently attracted so much attention is of the same nature4 ,in these cases what we have is either a conversion of heat rays into light rays 7as in the powdered fluor-spar71 or the absorption and giving out again of sun-rays4 ,in the latter case the phenomenon is essentially the same as fluorescence1 in which the dark rays of the solar spectrum beyond the violet are made visible4 ,but we must now return to the other questions that have been started in relation to phosphorescence in animals4 ,there has been much speculation as to the object of this light1 and to the purposes it serves in ,nature4 ,probably no general answer can be given to this question4 ,it is no doubt impossible to show why so many animals have been endowed with this remarkable property2 but we may consider some of the effects which the possession of it has in different cases4 ,in the first place1 it will undoubtedly serve in many cases to afford light to enable the animal to see by1 and in the ,lampyrid it would seem that the degree of luminosity is related to the development of the vision4 ,in that family1 according to the ,rev4 ,h4,s4 ,gorham1 the eyes are developed1 as a rule1 in inverse proportion to the luminosity4 ,where there is an ample supply of this kind of light the eyes are small1 but where the light is insignificant the eyes are large by way of compensation4 ,and moreover1 where both eyes and light are small1 then the antennae are large and feathery1 so that the deficiency in the sense of sight is made up for by an unusual development in the organs of touch4 ,but it is none the less certain that the presence of this light cannot always be designed to serve this purpose1 for many of the animals so endowed are blind4 ,the phosphorescent centipedes are without eyes1 like all the other members of the genus 7,geophilus7 to which they belong1 and probably the majority of phosphorescent marine forms are likewise destitute of organs of sight4 ,another suggestion is that the light derived from these marine forms1 and especially from deep-sea ,alcyonarians1 is what enables the members of the deep-sea fauna that are possessed of eyes 7which are always enormously enlarged7 to see4 ,such is the suggestion of ,dr4 ,carpenter1 ,sir ,wyville ,thomson1 and ,mr4 ,gwyn ,jeffries2 and it is possible that this actually is one of the effects of the phosphorescent property4 ,but if so1 it remains to inquire how the forms endowed with it came to be possessed of a power useful in that way to other forms1 but not to themselves4 ,according to the ,darwinian doctrine of development1 the powers that are developed in different organisms by the process of natural selection are such as are useful to themselves and not to others1 unless incidentally4 ,this consideration has led to another suggestion1 namely1 that the property of phosphorescence serves as a protection to the forms possessing it1 driving away enemies in one way or another3 it may be by warning them of the fact that they are unpalatable food1 as is believed to be the case with the colors of certain brilliantly-colored caterpillars2 it may be in other ways4 ,in ,kirby and ,spence one case is recorded in which the phosphorescence of the common phosphorescent centipede 7,geophilus electricus7 was actually seen apparently to serve as a means of defence against an enemy4 ,mr4 ,shepherd1 says that authority1 once noticed a scarabeus running round the last-mentioned insect when shining1 as if wishing1 but afraid to attack it4 ,in the case of the jelly-fishes1 it has been pointed out that their well-known urticating or stinging powers would make them at least unpleasant1 if not dangerous1 food for fishes2 and that consequently the luminosity by which so many of them are characterized at night may serve at once as a warning to predatory fishes and as a protection to themselves4 ,the experience of the unpleasant properties of many phosphorescent animals may likewise have taught fishes to avoid all forms possessing this attribute1 even though many of them might be quite harmless4 ,lastly1 it has been suggested that the phosphorescence in the female glow-worm may be designed to attract the male2 and that it will actually have this effect may readily be taken for granted4 ,observation shows that the male glow-worm is very apt to be attracted by a light4 ,gilbert ,white of ,selborne mentions that they1 attracted by the light of the candles1 came into his parlor4 ,another observer states that by the same light he captured as many as forty male glow-worms in one night4 ,illustration ,,comets 7,,from ,,marvels ,,of ,,the ,,heavens47 ,,by ,,camille ,,flammarion4 ,je viens vous annoncer une grande nouvelle3 ,nous l'avons1 en dormant1 madame1 chapp belle4 ,un monde prs de nous a pass tout du long1 ,est chu tout au travers de notre tourbillon2 ,et s'il et en chemin rencontr notre terre1 ,elle et t brise en morceaux comme verre4 ,,moli,,re4 ,illustration ,this announcement of ,trissontin's to ,philaminte1 who begins the parody on the fears caused by the appearance of comets1 would not have been a parody four or five centuries ago4 ,these tailed bodies1 which suddenly come to light up the heavens1 were for long regarded with terror1 like so many warning signs of divine wrath4 ,men have always thought themselves much more important than they really are in the universal order2 they have had the vanity to pretend that the whole creation was made for them1 whilst in reality the whole creation does not suspect their existence4 ,the ,earth we inhabit is only one of the smallest worlds2 and therefore it can scarcely be for it alone that all the wonders of the heavens1 of which the immense majority remains hidden from it1 were created4 ,in this disposition of man to see in himself the centre and the end of everything1 it was easy indeed to consider the steps of nature as unfolded in his favor2 and if some unusual phenomenon presented itself1 it was considered to be without doubt a warning from ,heaven4 ,if these illusions had had no other result than the amelioration of the more timorous of the community one would regret these ages of ignorance2 but not only were these fancied warnings of no use1 seeing that once the danger passed1 man returned to his former state2 but they also kept up among people imaginary terrors1 and revived the fatal resolutions caused by the fear of the end of the world4 ,when one fancies the world is about to end1--and this has been believed for more than a thousand years1--no solicitude is felt in the work of improving this world2 and1 by the indifference or disdain into which one falls1 periods of famine and general misery are induced which at certain times have overtaken our community4 ,why use the wealth of a world which is going to perish8 ,why work1 be instructed1 or rise in the progress of the sciences or arts8 ,much better to forget the world1 and absorb one's self in the barren contemplation of an unknown life4 ,it is thus that ages of ignorance weigh on man1 and thrust him further and further into darkness1 while ,science makes known by its influence on the whole community1 its great value1 and the magnitude of its aim4 ,the history of a comet would be an instructive episode of the great history of the heavens4 ,in it could be brought together the description of the progressive movement of human thought1 as well as the astronomical theory of these extraordinary bodies4 ,let us take1 for example1 one of the most memorable and best-known comets1 and give an outline of its successive passages near the ,earth4 ,like the planetary worlds1 ,comets belong to the solar system1 and are subject to the rule of the ,star ,king4 ,it is the universal law of gravitation which guides their path2 solar attraction governs them1 as it governs the movement of the planets and the small satellites4 ,the chief point of difference between them and the planets is1 that their orbits are very elongated2 and1 instead of being nearly circular1 they take the elliptical form4 ,in consequence of the nature of these orbits1 the same comet may approach very near the ,sun1 and afterwards travel from it to immense distances4 ,thus1 the period of the ,comet of #afhj has been estimated at three thousand years4 ,it approaches the ,sun1 so as to be nearer to it than our ,moon is to us1 whilst it recedes to a distance #hec times greater than the distance of the ,earth from the ,sun4 ,on the #agth of ,december1 #afhj1 it was at its perihelion--that is1 at its greatest proximity to the ,sun2 it is now continuing its path beyond the ,neptunian orbit4 ,its velocity varies according to its distance from the solar body4 ,at its perihelion it travels thousands of leagues per minute2 at its aphelion it does not pass over more than a few yards4 ,its proximity to the ,sun in its passage near that body caused ,newton to think that it received a heat twenty-eight thousand times greater than that we experience at the summer solstice2 and that this heat being two thousand times greater than that of red-hot iron1 an iron globe of the same dimensions would be fifty thousand years entirely losing its heat4 ,newton added that in the end comets will approach so near the ,sun that they will not be able to escape the preponderance of its attraction1 and that they will fall one after the other into this brilliant body1 thus keeping up the heat which it perpetually pours out into space4 ,such is the deplorable end assigned to comets by the author of the ,principia1 an end which makes ,de la ,brtonne say to ,rtif3 ,an immense comet1 already larger than ,jupiter1 was again increased in its path by being blended with six other dying comets4 ,thus displaced from its ordinary route by these slight shocks1 it did not pursue its true elliptical orbit2 so that the unfortunate thing was precipitated into the devouring centre of the ,sun4 ,it is said1 added he1 that the poor comet1 thus burned alive1 sent forth dreadful cries6 ,illustration3 ,a ,,comet ,it will be interesting1 then1 in a double point of view1 to follow a comet in its different passages in sight of the ,earth4 ,let us take the most important in astronomical history--the one whose orbit has been calculated by ,edmund ,halley1 and which was named after him4 ,it was in #afhb that this comet appeared in its greatest brilliancy1 accompanied with a tail which did not measure less than thirty-two millions of miles4 ,by the observation of the path which it described in the heavens1 and the time it occupied in describing it1 this astronomer calculated its orbit1 and recognized that the comet was the same as that which was admired in #aeca and #afjg1 and which ought to have reappeared in #agei4 ,never did scientific prediction excite a more lively interest4 ,the comet returned at the appointed time2 and on the #abth of ,march1 #agei1 reached its perihelion4 ,since the year #ab before the ,christian era1 it had presented itself twenty-four times to the ,earth4 ,it was principally from the astronomical annals of ,china that it was possible to follow it up to this period4 ,its first memorable appearance in the history of ,france is that of #hcg1 in the reign of ,louis le ,dbonnaire4 ,an anonymous writer of chronicles of that time1 named ,the ,astronomer1 gave the following details of this appearance1 relative to the influence of the comet on the imperial imagination3 ,during the holy days of the solemnization of ,easter1 a phenomenon ever fatal1 and of gloomy foreboding1 appeared in the heavens4 ,as soon as the ,emperor1 who paid attention to these phenomena1 received the first announcement of it1 he gave himself no rest until he had called a certain learned man and myself before him4 ,as soon as ,i arrived1 he anxiously asked me what ,i thought of such a sign2 ,i asked time of him1 in order to consider the aspects of the stars1 and to discover the truth by their means1 promising to acquaint him on the morrow2 but the ,emperor1 persuaded that ,i wished to gain time1 which was true1 in order not to be obliged to announce anything fatal to him1 said to me3 ',go on the terrace of the palace and return at once to tell me what you have seen1 for ,i did not see this star last evening1 and you did not point it out to me2 but ,i know that it is a comet2 tell me what you think it announces to me4' ,then scarcely allowing me time to say a word1 he added3 ',there is still another thing you keep back2 it is that a change of reign and the death of a prince are announced by this sign4' ,and as ,i advanced the testimony of the prophet1 who said3 ',fear not the signs of the heavens as the nations fear them1' the prince with his grand nature1 and the wisdom which never forsook him1 said1 ',we must not only fear ,him who has created both us and this star4 ,but as this phenomenon may refer to us1 let us acknowledge it as a warning from ,heaven4 ,louis le ,dbonnaire gave himself and his court to fasting and prayer1 and built churches and monasteries4 ,he died three years later1 in #hdj1 and historians have profited by this slight coincidence to prove that the appearance of the comet was a harbinger of death4 ,the historian1 ,raoul ,glader1 added later3 ,these phenomena of the universe are never presented to man without surely announcing some wonderful and terrible event4 ,halley's comet again appeared in ,april1 #ajff1 at the moment when ,william the ,conqueror invaded ,england4 ,it was pretended that it had the greatest influence on the fate of the battle of ,hastings1 which delivered over the country to the ,normans4 ,a contemporary poet1 alluding probably to the ,english diadem with which ,william was crowned1 had proclaimed in one place1 that the comet had been more favorable to ,william than nature had been to ,caesar2 the latter had no hair1 but ,william had received some from the comet4 ,a monk of ,malmesbury apostrophized the comet in these terms3 ,here thou art again1 thou cause of the tears of many mothers6 ,it is long since ,i have seen thee1 but ,i see thee now1 more terrible than ever2 thou threatenest my country with complete ruin6 ,in #adee1 the same comet made a more memorable appearance still4 ,the ,turks and ,christians were at war1 the ,west and the ,east seemed armed from head to foot--on the point of annihilating each other4 ,the crusade undertaken by ,pope ,calixtus ,,iii4 against the invading ,saracens1 was waged with redoubled ardor on the sudden appearance of the star with the flaming tail4 ,mahomet ,,ii4 took ,constantinople by storm1 and raised the siege of ,belgrade4 ,but the ,pope having put aside both the curse of the comet1 and the abominable designs of the ,mussulmans1 the ,christians gained the battle1 and vanquished their enemies in a bloody fight4 ,the ,angelus to the sound of bells dates from these ordinances of ,calixtus ,,iii4 referring to the comet4 ,in his poem on astronomy1 ,daru1 of the ,french ,academy1 describes this episode in eloquent terms3 ,un autre ,mahomet a-t-il d'un bras puissant ,aux murs de ,constantine arbor le croissant3 ,le ,danube tonn se trouble au bruit des armes1 ,la ,grce est dans les fers1 l',europe est en alarmes2 ,et pour comble d'horreur1 l'astre au visage ardent ,de ses ailes de feu va couvrir l',occident4 ,au pied de ses autels1 qu'il ne saurait dfendre1 ,calixte1 l'oeil en pleurs1 le front convert de cendre1 ,conjure la comte1 objet de tant d'effroi3 ,regarde vers les cieux1 pontife1 et lve-toi6 ,l'astre poursuit sa course1 et le fer d',huniade ,arrte le vainqueur1 qui tombe sous ,belgrade4 ,dans les cieux cependant le globe suspendu1 ,par la loi gnrale jamais retenu1 ,ignore les terreurs1 l'existence de ,rome1 ,et la ,terre peut-tre1 et jusqu'au nom de l'homme1 ,de l'homme1 tre crdule1 atome ambitieux1 ,qui tremble sous un prtre et qui lit dans les cieux4 ,this ancient comet witnessed many revolutions in human history1 at each of its appearances1 even in its later ones1 in #afhb1 #agei1 #ahce2 it was also presented to the ,earth under the most diverse aspects1 passing through a great variety of forms1 from the appearance of a curved sabre1 as in #adef1 to that of a misty head1 as in its last visit4 ,moreover1 this is not an exception to the general rule1 for these mysterious stars have had the gift of exercising a power on the imagination which plunged it in ecstasy or trouble4 ,swords of fire1 bloody crosses1 flaming daggers1 spears1 dragons1 fish1 and other appearances of the same kind1 were given to them in the middle ages and the ,renaissance4 ,comets like those of #aegg appear1 moreover1 to justify by their strange form the titles with which they are generally greeted4 ,the most serious writers were not free from this terror4 ,thus1 in a chapter on celestial monsters1 the celebrated surgeon1 ,ambroise ,par1 described the comet of #aebh under the most vivid and frightful colors3 ,this comet was so horrible and dreadful that it engendered such great terror to the people1 that they died1 some with fear1 others with illness4 ,it appeared to be of immense length1 and of blood color2 at its head was seen the figure of a curved arm1 holding a large sword in the hand as if it wished to strike4 ,at the point of the sword there were three stars1 and on either side was seen a great number of hatchets1 knives1 and swords covered with blood1 amongst which were numerous hideous human faces1 with bristling beards and hair4 ,the imagination has good eyes when it exerts itself4 ,the great and strange variety of cometary aspects is described with exactitude by ,father ,souciet in his ,latin poem on comets4 ,most of them1 says he1 shine with fires interlaced like thick hair1 and from this they have taken the name of comets4 ,one draws after it the twisted folds of a long tail2 another appears to have a white and bushy beard2 this one throws a glimmer similar to that of a lamp burning during the night2 that one1 ,o ,titan6 represents thy resplendent face2 and this other1 ,o ,phoebe6 the form of thy nascent horns4 ,there are some which bristle with twisted serpents4 ,shall ,i speak of those armies which have sometimes appeared in the air8 of those clouds which follow as it were along a circle1 or which resemble the head of ,medusa8 ,have there not often been seen figures of men or savage animals8 ,often1 in the gloom of night1 lighted up by these sad fires1 the horrible sound of arms is heard1 the clashing of swords which meet in the clouds1 the ether furiously resounding with fearful din which crush the people with terror4 ,all comets have a melancholy light1 but they have not all the same color4 ,some have a leaden color2 others that of flame or brass4 ,the fires of some have the redness of blood2 others resemble the brightness of silver4 ,some again are azure2 others have the dark and pale color of iron4 ,these differences come from the diversity of the vapors which surround them1 or from the different manner in which they receive the ,sun's rays4 ,do you not see in our fires1 that various kinds of wood produce different colors8 ,pines and firs give a flame mixed with thick smoke1 and throw out little light4 ,that which rises from sulphur and thick bitumen is bluish4 ,lighted straw gives out sparks of a reddish color4 ,the large olive1 laurel1 ash of ,parnassus1 etc41 trees which always retain their sap1 throw a whitish light similar to that of a lamp4 ,thus1 comets whose fires are formed of different materials1 each take and preserve a color which is peculiar to them4 ,instead of being a cause of fear and terror1 the variety and variability of the aspect of comets ought rather to indicate to us the harmlessness of their nature4 ,illustration ,,the ,,total ,,solar ,,eclipse ,,of #ahhc ,,an ,,astronomers ,,voyage ,,to ,,fairy-,,land4 7,,from ,,the ,,atlantic ,,monthly1 ,,may1 #ahij47 ,,by ,,prof4 ,e4,s4 ,,holden4 ,illustration ,in #ahhc calculations showed that a solar eclipse of unusually long duration 7#e minutes1 #bj seconds7 would occur in the ,south ,pacific ,ocean4 ,the track of the eclipse lay south of the equator1 but north of ,tahiti4 ,there were in fact only two dots of coral islands on the charts in the line of totality1 ,caroline ,island1 and one hundred and fifty miles west ,flint ,island 7longitude #aej west1 latitude #aj south74 ,almost nothing was known of either of these minute points4 ,the station of the party under my charge 7sent out by the ,united ,states government under the direction of the ,national ,academy of ,sciences7 was to be ,caroline ,islands4 ,every inch of that island 7seven miles long1 a mile or so broad7 is familiar now2 but it is almost ludicrous to recollect with what anxiety we pored over the hydrographic charts and sailing instructions of the various nations1 to find some information1 however scanty1 about the spot which was to be our home for nearly a month4 ,all that was known was that this island had formerly been occupied as a guano station4 ,there was a landing then4 ,after the personnel of the party had been decided on1 there were the preparations for its subsistence to be looked out for4 ,how to feed seventeen men for twenty-one days8 ,fortunately the provisions that we took1 and the fresh fish caught for us by the natives1 just sufficed to carry us through with comfort and with health4 ,in ,march of #ahhc we sailed from ,new ,york1 and about the same time a ,french expedition left ,europe bound for the same spot4 ,from ,new ,york to ,panama1 from ,panama to ,lima1 were our first steps4 ,here we joined the ,united ,states steamship ,hartford1 ,admiral ,farragut's flagship1 and the next day set sail for our destined port1--if a coral reef surrounded by a raging surf can be called a port4 ,about the same time a party of ,french observers under ,monsieur ,janssen1 of the ,paris ,academy of ,sciences1 left ,panama in the ,eclaireur4 ,illustration3 ,,bird',s ,,eye ,,view ,,of ,,the ,,caroline ,,islands4 ,it was an ocean race of four thousand miles due west4 ,the station ,caroline ,islands was supposed to be more desirable than ,flint ,island4 ,admiral ,wilkes's expedition had lain off the latter several days without being able to land on account of the tremendous surf1 so that it was eminently desirable to beat the ,frenchman1 as the sailors put it4 ,with this end in view our party had secured 7through a member of the ,national ,academy in ,washington7 the verbal promise of the proper official of the ,navy ,department that the ,hartford's orders should read to burn coal as necessary4 ,the last obstacle to success was thus removed4 ,we were all prepared1 and now the ship would take us speedily to our station4 ,imagine our feelings the next day after leaving ,callao1 when the commanding officer of the ,hartford opened his sealed orders4 ,they read 7dated ,washington1 in ,february71 ,to arrive at ,caroline ,islands 7in ,april7 with full coal-bunkers6 ,officialism could go no further4 ,here was an expedition sent on a slow-sailing ship directly through the regions of calms for four thousand miles4 ,it was of no possible use to send the expedition at all unless it arrived in time4 ,and here were our orders to arrive with full coal-bunkers4 ,fortunately we had unheard-of good-luck4 ,the trade-wind blew for us as it did for the ,ancient ,mariner1 and we sped along the parallel of #ab south at the rate of one hundred and fifty miles a day under sail1 while the ,eclaireur was steaming for thirty days a little nearer the equator in a dead calm4 ,we arrived off the island just in time1 with not a day to spare4 ,it was a narrow escape1 and a warning to all of us never to sail again under sealed orders unless we knew what was under the seal4 ,here we were1 then1 lying off the island and scanning its sparse crown of cocoanut palms1 looking for a ,french flag among their wavy tufts4 ,there was none in sight4 ,we were the winners in the long race4 ,directly a whale-boat was lowered1 and rowed around the white fringe of tremendous surf that broke ceaselessly against the vertical wall of coral rock4 ,there was just one narrow place where the waves rolled into a sort of cleft and did not break4 ,here was the landing1 then4 ,landing was an acrobatic feat4 ,in you went on the crest of a wave1 pointing for the place where the blue seas did not break into white4 ,an instant after1 you were in the quiet water inside of the surf4 ,jump out everybody and hold the boat6 ,then it was pick up the various instruments1 and carry them for a quarter of a mile to high-water mark and beyond1 over the sharp points of the reef4 ,in one night we were fairly settled2 in another the ,hartford had sailed away1 leaving us in our fairy paradise1 where the corals and the fish were of all the brilliant hues of the rainbow1 and where the whiteness of the sand1 the emerald of the lagoon1 and the turquoise of the ocean made a picture of color and form never to be forgotten4 ,but where are the ,frenchmen8 ,the next morning there is the ,eclaireur lying a mile or so out1 and there is a boat with the bo'sun--matre d'quipage--pulling towards the surf4 ,i wade out to the brink4 ,he halloes3 ,where is the landing1 then8 ,mais ici--,right here1--,i say4 ,yes1 that's all very well for persons1 but where do you land les bagages8 ,mais ici ,i say again1 and he says1 ,diable6 ,but all the same he lands both persons and baggage in a neat1 sailor-like way4 ,in a couple of days our two parties of fifty persons had taken possession of this fairy isle4 ,observatories go up1 telescopes1 spectroscopes1 photographic cameras are pointed and adjusted4 ,the eventful day arrives4 ,everything is successful4 ,then comes the ,hartford and takes us away1 and a few days later comes the ,eclaireur1 and the ,frenchmen are gone4 ,the little island is left there1 abandoned to the five natives who tend the sickly plantation of cocoa-palms1 and live from year to year with no incident but the annual visit of the blig 7,kanaka for brig71 which brings their store of ship biscuit and molasses4 ,illustration3 ,,observatories ,,go ,,up4 ,think of their stupendous experience6 ,for years and years they have lived like that in the marvellous1 continuous charm of the silent island4 ,the blig had come and gone away this year1 and there will be no more disturbance and discord for a twelve-month longer4 ,surely1 surely1 slumber is more sweet than toil1 the shore ,than labor in the deep mid-ocean1 wind1 and wave1 and oar1 ,then rest ye1 brother mariners1 we will not wander more6 ,not so6 for here comes a great warship out of the ,east under a press of canvas4 ,what event is this8 ,see6 she clews up her light sails and fires an eleven-inch gun6 ,one of those guns of ,mobile ,bay4 ,then swarms out the starboard watch1 one hundred and sixty strong1 and a fleet of boats brings ashore these pale astronomers with those useless tubes that they point at the sky every night4 ,but there are useful things too2 cooking-stoves1 and lumber1 and bricks4 ,what is all this8 ,no sooner are these established than comes another ship and fires its gun6 and another set of hardy sailormen pours out1 and here is another party of madmen with tubes1--yes1 and with cooking-stoves and lumber1 too4 ,then comes the crowning1 stupendous1 and unspeakable event4 ,the whole sun is hidden and the heavens are lighted up with pearly streamers6 ,in the name of all the ,polynesian gods1 what is the meaning of all this8 ,and then in a few days all these are gone4 ,all the madmen4 ,they have taken away the useless tubes1 but they have left their houses standing4 ,their splendid1 priceless1 precious cook-stoves are here4 ,see6 here is a frying-pan6 here are empty tin cans6 and a keg of nails6 ,they must have forgotten all this1 madmen as they are6 ,and the little island sinks back to its quiet and its calm4 ,the lagoon lies placid like a mirror4 ,the slow sea breaks eternally on the outer reef4 ,the white clouds sail over day by day4 ,the seabirds come back to their haunts1--the fierce man-of-war birds1 the gentle1 soft-eyed tern4 ,but we1 whose island home was thus invaded--are we the same8 ,was this a dream8 ,will it happen again next year8 every year8 ,what indeed was it that happened1--or in fact1 did it happen at all8 ,is it not a dream1 indeed8 ,if we left those peaceful ,kanakas to their dream1 we ,americans have brought ours away with us4 ,who will forget it8 ,which of us does not wish to be in that peaceful fairyland once more8 ,that is the personal longing4 ,but we have all come back1 each one with his note-books full2 and in a few weeks the stimulus of accustomed habit has taken possession of us again4 ,right and wrong are again determined by municipal sanctions4 ,we have become useful citizens once more4 ,perhaps it is just as well4 ,we should have been poor poets1 and we do not forget4 ,so ends the astronomer's voyage to fairyland4 ,illustration ,,halos--,,parhelia--,,the ,,spectre ,,of ,,the ,,brocken1 ,,etc 7,,from ,,the ,,atmosphere47 ,,by ,,camille ,,flammarion4 ,illustration ,treatises on meteorology have not1 up to the present day1 classified with sufficient regularity the divers optical phenomena of the air4 ,some of these phenomena have1 however1 been seen but rarely1 and have not been sufficiently studied to admit of their classification4 ,we have examined the common phenomenon of the rainbow and we have seen that it is due to the refraction and reflection of light on drops of water1 and that it is seen upon the opposite side of the sky to the sun in day-time1 or the moon at night4 ,we are now about to consider an order of phenomena which are of rarer occurrence1 but which have this property in common with the rainbow1 viz41 that they take place also upon the side of the sky opposite to the sun4 ,these different optical effects are classed together under the name of anthelia 7from ,greek1 opposite to1 and ,greek1 the sun74 ,the optical phenomena which occur on the same side as1 or around the sun1 such as halos1 parhelia1 etc41 will be dealt with later on4 ,before coming to the anthelia1 properly so called1 or to the colored rings which appear around a shadow1 it is as well first to note the effects produced on the clouds and mists that are facing the sun when it rises or sets4 ,upon high mountains1 the shadow of the mountain is often seen thrown either upon the surface of the lower mists or upon the neighboring mountains1 and projected opposite to the sun almost horizontally4 ,i once saw the shadow of the ,righi very distinctly traced upon ,mount ,pilate1 which is situated to the west of the ,righi1 on the other side of the ,lake of ,lucerne4 ,this phenomenon occurs a few minutes after sunrise1 and the triangular form of ,righi is delineated in a shape very easy to recognize4 ,the shadow of ,mont ,blanc is discerned more easily at sunset4 ,,mm4 ,bravais and ,martins1 in one of their scientific ascents1 noticed it under specially favorable circumstances1 the shadow being thrown upon the snow-covered mountains1 and gradually rising in the atmosphere until it reached a height of #a1 still remaining quite visible4 ,the air above the cone of the shadow was tinted with that rosy purple which is seen1 in a fine sunset1 coloring the lofty peaks4 ,imagine1 says ,bravais1 the other mountains also projecting1 at the same moment1 their shadows into the atmosphere1 the lower parts dark and slightly greenish1 and above each of these shadows the rosy surface1 with the deeper rose of the belt which separates it from them2 add to this the regular contour of the cones of the shadow1 principally at the upper edge1 and lastly1 the laws of perspective causing all these lines to converge the one to the other toward the very summit of the shadow of ,mont ,blanc2 that is to say1 to the point of the sky where the shadows of our own selves were2 and even then one will have but a faint idea of the richness of the meteorological phenomenon displayed before our eyes for a few instants4 ,it seemed as though an invisible being was seated upon a throne surrounded by fire1 and that angels with glittering wings were kneeling before him in adoration4 ,among the natural phenomena which now attract our attention1 but fail to excite our surprise1 there are some which possess the characteristics of a supernatural intervention4 ,the names which they have received still bear witness to the terror which they once inspired2 and even to-day1 when science has stripped them of their marvellous origin1 and explained the causes of their production1 these phenomena have retained a part of their primitive importance1 and are welcomed by the savant with as much interest as when they were attributed to divine agency4 ,out of a large and very diverse number1 ,i will first select the ,spectre of the ,brocken4 ,the ,brocken is the highest mountain in the picturesque ,hartz chain1 running through ,hanover1 being three hundred and thirty feet above the level of the sea4 ,one of the best descriptions of this phenomenon is given by the traveller ,hane1 who witnessed it on the #bc;d of ,may1 #agig4 ,after having ascended no less than thirty miles to the summit1 he had the good fortune at last to contemplate the object of his curiosity4 ,the sun rose at about four o'clock1 the weather being fine1 and the wind driving off to the west the transparent vapors which had not yet had time to be condensed into clouds4 ,about a quarter-past four1 ,hane saw in this direction a human figure of enormous dimensions4 ,a gust of wind nearly blowing off his hat at that moment1 he raised his hand to secure it1 and the colossal figure imitated his action4 ,hane1 noticing this1 at once made a stooping movement1 and this was also reproduced by the spectre4 ,he then called another person to him1 and placing themselves in the very spot where the apparition was first seen1 the pair kept their eyes fixed on the ,achtermannshohe1 but saw nothing4 ,after a short interval1 however1 two colossal figures appeared1 which repeated the gestures made by them1 and then disappeared4 ,some few years ago1 in the summer of #ahfb1 a ,french artist1 ,m4 ,stroobant1 witnessed and carefully sketched this phenomenon1 which is drawn in full-page illustration1 opposite p4 #bgb4 ,he had slept at the inn of the ,brocken1 and rising at two in the morning1 he repaired to the plateau upon the summit in the company of a guide4 ,they reached the highest point just as the first glimmer of the rising sun enabled them to distinguish clearly objects at a great distance4 ,to use ,m4 ,stroobant's own words1 ,my guide1 who had for some time appeared to be walking in search of something1 suddenly led me to an elevation whence ,i had the singular privilege of contemplating for a few instants the magnificent effect of mirage1 which is termed the ,spectre of the ,brocken4 ,the appearance is most striking4 ,a thick mist1 which seemed to emerge from the clouds like an immense curtain1 suddenly rose to the west of the mountain1 a rainbow was formed1 then certain indistinct shapes were delineated4 ,first1 the large tower of the inn was reproduced upon a gigantic scale2 after that we saw our two selves in a more vague and less exact shape1 and these shadows were in each instance surrounded by the colors of the rainbow1 which served as a frame to this fairy picture4 ,some tourists who were staying at the inn had seen the sun rise from their windows1 but no one had witnessed the magnificent spectacle which had taken place on the other side of the mountain4 ,sometimes these spectres are surrounded by colored concentric arcs4 ,since the beginning of the present century1 treatises on meteorology designate1 under the name of the ,ulloa circle1 the pale external arch which surrounds the phenomenon1 and this same circle has sometimes been called the white rainbow4 ,but it is not formed at the same angular distance as the rainbow1 and1 although pale1 it often envelops a series of interior colored arcs4 ,illustration3 ,,the ,,spectre ,,of ,,the ,,brocken ,ulloa1 being in company with six fellow-travellers upon the ,pambamarca at daybreak one morning1 observed that the summit of the mountain was entirely covered with thick clouds1 and that the sun1 when it rose1 dissipated them1 leaving only in their stead light vapors1 which it was almost impossible to distinguish4 ,suddenly1 in the opposite direction to where the sun was rising1 each of the travellers beheld1 at about seventy feet from where he was standing1 his own image reflected in the air as in a mirror4 ,the image was in the centre of three rainbows of different colors1 and surrounded at a certain distance by a fourth bow with only one color4 ,the inside color of each bow was carnation or red1 the next shade was violet1 the third yellow1 the fourth straw color1 the last green4 ,all these bows were perpendicular to the horizon2 they moved in the direction of1 and followed1 the image of the person they enveloped as with a glory4 ,the most remarkable point was that1 although the seven spectators were standing in a group1 each person only saw the phenomenon in regard to his own person1 and was disposed to disbelieve that it was repeated in respect to his companions4 ,the extent of the bows increased continually and in proportion to the height of the sun2 at the same time their colors faded away1 the spectre became paler and more indistinct1 and finally the phenomenon disappeared altogether4 ,at the first appearance the shape of the bows was oval1 but toward the end they became quite circular4 ,the same apparition was observed in the polar regions by ,scoresby1 and described by him4 ,he states that the phenomenon appears whenever there is mist and at the same time shining sun4 ,in the polar seas1 whenever a rather thick mist rises over the ocean1 an observer1 placed on the mast1 sees one or several circles upon the mist4 ,illustration3 ,,the ,,ulloa ,,circle4 ,these circles are concentric1 and their common centre is in the straight line joining the eye of the observer to the sun1 and extended from the sun toward the mist4 ,the number of circles varies from one to five2 they are particularly numerous and well colored when the sun is very brilliant and the mist thick and low4 ,on ,july #bc1 #ahba1 ,scoresby saw four concentric circles around his head4 ,the colors of the first and of the second were very well defined2 those of the third1 only visible at intervals1 were very faint1 and the fourth only showed a slight greenish tint4 ,the meteorologist ,kaemtz has often observed the same fact in the ,alps4 ,whenever this shadow was projected upon a cloud1 his head appeared surrounded by a luminous aureola4 ,to what action of light is this phenomenon due8 ,bouguer is of opinion that it must be attributed to the passage of light through icy particles4 ,such1 also1 is the opinion of ,de ,saussure1 ,scoresby1 and other meteorologists4 ,in regard to the mountains1 as we cannot assure ourselves directly of the fact by entering the clouds1 we are reduced to conjecture4 ,the aerostat traversing the clouds completely1 and passing by the very point where the apparition is seen1 affords one an opportunity of ascertaining the state of the cloud4 ,this observation ,i have been able to make1 and so to offer an explanation of the phenomenon4 ,as the balloon sails on1 borne forward by the wind1 its shadow travels either on the ground or on the clouds4 ,this shadow is1 as a rule1 black1 like all others2 but it frequently happens that it appears alone on the surface of the ground1 and thus appears luminous4 ,examining this shadow by the aid of a telescope1 ,i have noticed that it is often composed of a dark nucleus and a penumbra of the shape of an aureola4 ,this aureola1 frequently very large in proportion to the diameter of the central nucleus1 eclipses it to the naked eye1 so that the whole shadow appears like a nebulous circle projected in yellow upon the green ground of the woods and meadows4 ,i have noticed1 too1 that this luminous shadow is generally all the more strongly marked in proportion to the greater humidity of the surface of the ground4 ,seen upon the clouds1 this shadow sometimes presents a curious aspect4 ,i have often1 when the balloon emerged from the clouds into the clear sky1 suddenly perceived1 at twenty or thirty yards' distance1 a second balloon distinctly delineated1 and apparently of a grayish color1 against the white ground of the clouds4 ,this phenomenon manifests itself at the moment when the sun re-appears4 ,the smallest details of the car can be made out clearly1 and our gestures are strikingly reproduced by the shadow4 ,illustration3 ,,the ,,shadow ,,of ,,the ,,balloon ,,was ,,seen ,,by ,,us4 ,on ,april #ae1 #ahfh1 at about half-past three in the afternoon1 we emerged from a stratum of clouds1 when the shadow of the balloon was seen by us1 surrounded by colored concentric circles1 of which the car formed the centre4 ,it was very plainly visible upon a yellowish white ground4 ,a first circle of pale blue encompassed this ground and the car in a kind of ring4 ,around this ring was a second of a deeper yellow1 then a grayish red zone1 and lastly as the exterior circumference1 a fourth circle1 violet in hue1 and imperceptibly toning down into the gray tint of the clouds4 ,the slightest details were clearly discernible--net1 robes1 and instruments4 ,every one of our gestures was instantaneously reproduced by the aerial spectres4 ,the anthelion remained upon the clouds sufficiently distinct1 and for a sufficiently long time1 to permit of my taking a sketch in my journal and studying the physical condition of the clouds upon which it was produced4 ,i was able to determine directly the circumstances of its production4 ,indeed1 as this brilliant phenomenon occurred in the midst of the very clouds which ,i was traversing1 it was easy for me to ascertain that these clouds were not formed of frozen particles4 ,the thermometer marked #b above zero4 ,the hygrometer marked a maximum of humidity experienced1 namely1 seventy-seven at three thousand seven hundred and seventy feet1 and the balloon was then at four thousand six hundred feet1 where the humidity was only seventy-three4 ,it is therefore certain that this is a phenomenon of the diffraction of light simply produced by the vesicles of the mist4 ,the name of diffraction is given to all the modifications which the luminous rays undergo when they come in contact with the surface of bodies4 ,light1 under these circumstances1 is subject to a sort of deviation1 at the same time becoming decomposed1 whence result those curious appearances in the shadows of objects which were observed for the first time by ,grimaldi and ,newton4 ,the most interesting phenomena of diffraction are those presented by gratings1 as are technically denominated the systems of linear and very narrow openings situated parallel to one another and at very small intervals4 ,a system of this kind may be realized by tracing with a diamond1 for instance1 on a pane of glass equidistant lines very close together4 ,as the light would be able to pass in the interstices between the strokes1 whereas it would be stopped in the points corresponding to those where the glass was not smooth1 there is1 in reality1 an effect produced as if there were a series of openings very near to each other4 ,a hundred strokes1 about #a_/beth of an inch in length1 may thus be drawn without difficulty4 ,the light is then decomposed in spectra1 each overlapping the other4 ,it is a phenomenon of this kind which is seen when we look into the light with the eye half closed2 the eyelashes in this case1 acting as a net-work or grating4 ,these net-works may also be produced by reflection1 and it is to this circumstance that are due the brilliant colors observed when a pencil of luminous rays is reflected on a metallic surface regularly striated4 ,to the phenomena of gratings must be attributed1 too1 the colors1 often so brilliant1 to be seen in mother-of-pearl4 ,this substance is of a laminated structure2 so much so1 that in carving it the different folds are often cut in such a way as to form a regular net-work upon the surface4 ,it is1 again1 to a phenomenon of this sort that are due the rainbow hues seen in the feathers of certain birds1 and sometimes in spiders' webs4 ,the latter1 although very fine1 are not simple1 for they are composed of a large number of pieces joined together by a viscous substance1 and thus constitute a kind of net-work4 ,if the sun is near the horizon1 and the shadow of the observer falls upon the grass1 upon a field of corn1 or other surface covered with dew1 there is visible an aureola1 the light of which is especially bright about the head1 but which diminishes from below the middle of the body4 ,this light is due to the reflection of light by the moist stubble and the drops of dew4 ,it is brighter about the head1 because the blades that are near where the shadow of the head falls expose to it all that part of them which is lighted up1 whereas those farther off expose not only the part which is lighted up1 but other parts which are not1 and this diminishes the brightness in proportion as their distance from the head increases4 ,the phenomenon is seen whenever there is simultaneously mist and sun4 ,this fact is easily verified upon a mountain4 ,as soon as the shadow of a mountaineer is projected upon a mist1 his head gives rise to a shadow surrounded by a luminous aureola4 ,illustration3 ,,fog-,,bow ,,seen ,,from ,,the ,,matterhorn4 ,the ,illustrated ,london ,news of ,july #h1 #ahga1 illustrates one of these apparitions1 ,the ,fog-,bow1 seen from the ,matterhorn1 observed by ,e4 ,whymper in this celebrated region of the ,alps4 ,the observation was taken just after the catastrophe of ,july #ad1 #ahfe2 and by a curious coincidence1 two immense white aerial crosses projected into the interior of the external arc4 ,these two crosses were no doubt formed by the intersection of circles1 the remaining parts of which were invisible4 ,the apparition was of a grand and solemn character1 further increased by the silence of the fathomless abyss into which the four ill-fated tourists had just been precipitated4 ,illustration ,other optical appearances of an analogous kind are manifested under different conditions4 ,thus1 for instance1 if any one1 turning his back to the sun1 looks into water1 he will perceive the shadow of his head1 but always very much deformed4 ,at the same time he will see starting from this very shadow what seem to be luminous bodies1 which dart their rays in all directions with inconceivable rapidity1 and to a great distance4 ,these luminous appearances--these aureola rays--have1 in addition to the darting movement1 a rapid rotary movement around the head4 ,illustration ,,the ,,planet ,,venus ,,by ,,agnes ,m4 ,,clerke4 ,i4 ,,hesperus ,,and ,,phosphor4 ,illustration ,the radiant planet that hangs on the skirts of dusk and dawn like a jewel in an ,ethiop's ear1 has been known and sung by poets in all ages4 ,its supremacy over the remainder of the starry host is recognized in the name given it by the ,arabs1 those nomad watchers of the skies1 for while they term the moon ,el ,azhar1 the ,brighter ,one1 and the sun and moon together ,el ,azharan1 the ,brighter ,pair1 they call ,venus ,ez ,zahra1 the bright or shining one par excellence1 in which sense the same word is used to describe a flower4 ,this ,flower of ,night is supposed to be no other than the white rose into which ,adonis was changed by ,venus in the fable which is the basis of all early ,asiatic mythology4 ,the morning and evening star is thus the celestial symbol of that union between earth and heaven in the vivifying processes of nature1 typified in the love of the goddess for a mortal4 ,the ancient ,greeks1 on the other hand1 not unnaturally took the star1 which they saw alternately emerging from the effulgence of the rising and setting sun1 in the east and in the west1 for two distinct bodies1 and named it differently according to the time of its appearance4 ,the evening star they called ,hesperus1 and from its place on the western horizon1 fabled an earthly hero of that name1 the son of ,atlas1 who from the slopes of that mountain on the verge of the known world used to observe the stars until eventually carried off by a mighty wind1 and so translated to the skies4 ,these divine honors were earned by his piety1 wisdom1 and justice as a ruler of men1 and his name long shed a shimmering glory over those ,hesperidean regions of the earth1 where the real and unreal touched hands in the mystical twilight of the unknown4 ,but the morning star shone with a different significance as the herald of the day1 the torchbearer who lights the way for radiant ,aurora on her triumphal progress through the skies4 ,hence he was called ,eosphorus1 or ,phosphorus1 the bearer of the dawn1 translated into ,latin as ,lucifer1 the ,light-bearer4 ,the son of ,eos1 or ,aurora1 and the ,titan ,astraeus1 he was of the same parentage as the other multitude of the starry host1 to whom a similar origin was ascribed1 and from whom in ,greek mythology he was evidently believed to differ only in the superior order of his brightness4 ,homer1 who mentions the planet in the following passage3 ,but when the star of ,lucifer appeared1 ,the harbinger of light1 whom following close1 ,spreads o'er the sea the saffron-robed morn4 7,,lord ,,derby',s ,iliad47 recognizes no distinction between those celestial nomads1 the planets1 wandering stars1 as the ,arabs call them1 which visibly change their position relatively to the other stars1 and the latter1 whose places on the sphere are apparently fixed and immutable4 ,in this he and his compatriots were far behind the ancient ,egyptians1 who probably derived their knowledge from still earlier speculators in ,asia1 for they not only observed the movements of some at least of the planets1 but believed that ,mercury and ,venus revolved as satellites round the sun1 which in its turn circled round our lesser world4 ,pythagoras is said to have been the first to identify ,hesperus with ,phosphor1 as the ,silver planet both of eve and morn1 and by ,plato the same fact is recognized4 ,the other planets1 all of which had1 according to him1 been originally named in ,egypt and ,syria1 have each its descriptive title in his nomenclature4 ,thus the innermost1 the ,star of ,mercury1 is called ,stilbon1 the ,sparkler1 ,mars1 ,pyroeis1 the ,fiery ,one1 while ,jupiter1 the planet of the slowest course but one1 is designated as ,phaeton1 and ,saturn1 the tardiest of all1 ,phaenon4 ,these names were in later times abandoned in favor of those of the divinities to whom they were respectively dedicated1 unalterably associated now with the days of the week1 over which they have been selected to preside4 ,the ,copernican theory1 which once and forever brushed the cobwebs out of the sky1 by clearing away the mists of pre-existing error1 first completely explained the varying positions of the ,shepherd's star1 irradiating the first or last watch of night1 according to her alternate function as the follower or precursor of the sun4 ,as she travels on a path nearer to him by more than twenty-five and a half million miles than that of the earth1 she is seen by us on each side of him in turn after passing behind or in front of him4 ,the points at which her orbit expands most widely to our eyes--an effect of course entirely due to perspective1 as her distance from the sun is not then actually increased--are called her eastern and western elongations2 that at which she passes by the sun on the hither side her inferior1 and on the farther side her superior conjunction4 ,at both conjunctions she is lost to our view1 since she accompanies the sun so closely as to be lost in his beams1 rising and setting at the same time1 and travelling with him in his path through the heavens during the day4 ,when at inferior conjunction1 or between us and the sun1 she turns her dark hemisphere to us like the new moon1 and would consequently be invisible in any case1 but when in the opposite position1 shows us her illuminated face1 and is literally a day star1 invisible only because effaced by the solar splendor4 ,it is as she gradually separates from him1 after leaving this latter position1 circling over that half of her orbit which lies to the east of him1 that she begins to come into view as an evening star1 following him at a greater and greater distance1 and consequently setting later1 until she attains her greatest eastern elongation1 divided from the sun about #de of his visible circuit through the heavens1 and consequently remaining above the horizon for some four hours after him4 ,from this point she again appears to draw nearer to him until she passes on his hither side in inferior conjunction1 from which she emerges on the opposite side to the westward1 and begins to shine as a morning star1 preceding him on his track1 at a gradually increasing distance1 until attaining her greatest westward elongation1 and finally completing her cycle by returning to superior conjunction once more in a period of about five hundred and eighty-four days4 ,venus is thus ,hesperus or ,vesper1 the evening star1 when following the sun as she passes from beyond him in superior conjunction to inferior conjunction where she is nearest to the earth4 ,as she again leaves him behind in her course from this point to the opposite one of superior conjunction1 she appears in her second aspect as ,phosphorus or ,lucifer1 the sun of morning1 and herald of the day1 shining as ,the fair star ,that gems the glittering coronet of morn4 ,,ii4 ,,the ,,phases ,,of ,,venus4 ,but the changes in the aspect of ,venus due to her varying positions in her orbit are not confined to those which cause her to oscillate with a pendulum movement eastward and westward from the sun4 ,the discovery that she undergoes phases exactly like those of the moon1 followed that of the existence of ,jupiter's satellites as the second great result achieved by the use of the telescope in the hands of ,galileo4 ,the fact that the planets were intrinsically dark bodies revolving round the sun1 and reflecting its light1 as he and ,copernicus had maintained1 thus received a further ocular demonstration4 ,the ,florentine astronomer describes in a letter to a friend how the planet1 after emerging from superior conjunction as a morning star1 gradually loses her rotundity on the side remote from the luminary1 changing first to a half sphere and then to a waning crescent2 until1 after passing through the stage of absolute extinction when intervening between us and the sun1 she re-appears as a morning star1 and undergoes the same series of transformations in inverse order4 ,the revelation was indeed so novel and unexpected1 that when the slight deformation of the planet's shape was first detected by him1 he did not venture to announce it in plain terms but veiled it1 according to the prevailing fashion of the time1 under a ,latin anagram4 ,his celebrated sentence-- ,haec immatura a me jam frustra leguntur4 7,those incomplete observations are as yet read by me in vain47 forms1 by transposing the letters1 the more definite statement1 ,cynthi figuras mulatur ,mater ,amorum4 7,the mother of the loves imitates the aspects of ,diana47 that is to say1 ,venus vies with the phases of the moon4 ,the discovery was an important one from its bearing on popular superstition ascribing to the planets special influences on human affairs1 for since they were thus shown to transmit to us only borrowed light1 belief in their beneficent or malefic powers over man's destinies received a rude shock4 ,illustration3 ,,the ,,phases ,,op ,,venus4 ,galileo's announcement1 published in ,september1 #afaj1 when only a slight flattening of the planet's disk was visible1 received absolute confirmation in the ensuing months1 as she completed her full half-circle of change on ,february #bdth of the following year1 and consequently exhibited herself to him in all her varying aspects4 ,it was the first time they had been looked upon by a human eye1 since its unaided powers do not enable it to discern them1 although one exception to this rule is said to have existed4 ,this was the case of the ,swiss mathematician ,gauss1 who1 when a child1 on being shown the crescent star through the telescope1 exclaimed to his mother that it was turned wrong2 the inference being that he recognized the reversal of the image in the field of the glass4 ,if it were indeed so1 he deserves to rank with the ,siberian savage1 who described the eclipses1 or ,jupiter's satellites2 or the shoemaker of ,breslau1 who could see and declare the positions of those minute orbs4 ,the phases exhibited to us by ,venus are due to her moving in an orbit within that of the earth1 at one side of which she is between us and the sun1 while at the other this position is exactly reversed4 ,we may compare her to a performer in a great celestial circus1 lit by a central chandelier1 and ourselves to spectators in an external ring1 from which we see her at one time facing us with the light full on her1 at the opposite point in complete shadow1 and at the intermediate ones in varying degrees of illumination according to our changing views of her4 ,the same illustration may serve to show why ,venus is brightest1 not when full1 since she is then beyond the sun1 and at the farthest possible point from us1 but when she approaches us at inferior conjunction1 more nearly by over one hundred and thirty million miles1 and still shows us a crescent of her illuminated surface1 before passing into the last phase of total obscuration4 ,when actually nearest to us she is absolutely invisible1 being then1 like the new moon1 between us and the sun4 ,her varying degrees of brilliancy1 even when in the same phase1 are thus accounted for by her alternate retreat from and advance towards us as she circles round the sun4 ,completing1 as she does1 her revolution in about seven months and a half1 she would of course go through the whole series of her metamorphoses in that time1 were the earth1 from which we observe them1 a fixed point4 ,their protraction instead1 over a term of five hundred and eighty-four days1 or more than nineteen months1 is due to the simultaneous motion of the earth in the same direction1 over her larger orbit in a longer period1 causing the same relative position of the sister planet to recur only as often as she overtakes her in her career4 ,thus the hour and minute hands of a watch1 moving at different rates of speed after meeting on the dial plate at twelve o'clock1 will not again come together until five minutes past one1 when the swifter paced of the two will have completed a revolution and a twelfth4 ,but were we to retard the motion of the latter1 reducing it to only twice that of its companion1 they would always meet at the figure twelve1 as it would exactly complete two circuits while the hour hand was performing one4 ,venus thus overtakes and passes the earth once in five hundred and eighty-four days1 or nearly two and a half of her own years1 constituting what is called her synodic period of apparent revolution as seen from this globe4 ,she thus presents to us all the phases undergone by our own satellite during a lunar month1 passing from new to full1 and vice versa1 through the various intervening gradations of form4 ,the phases of ,venus are amongst the most beautiful subjects for observation in a moderate telescope1 as her silver bow1 gradually brightening in the evening dusk1 or fading in the dawn1 ,on a bed of daffodil sky1 is1 after the two greater luminaries that rule the day and night1 the most brilliant object in the heavens4 ,,iii4 ,,the ,,silver ,,crown4 ,the parallel between ,venus and ,that orbed maiden with fire laden1 ,whom mortals call the moon1 is carried a stage further4 ,most of us are familiar with the spectacle in which the ,ancient ,egyptians saw symbolized ,horus on the lap of ,isis1 but which we more prosaically term the old moon in the new moon's arms4 ,the strongly illuminated half circle next the sun is then seen embracing with its horns a dusky sphere1 contrasting with it as tarnished silver does with the newly burnished metal4 ,the same phenomenon is occasionally1 though very rarely1 exhibited by ,venus1 while close to the sun at inferior injunction1 when the shadowy form of the full orb is seen to shine dimly within her crescent with what is termed the ashen light4 ,more wonderful still1 this glimmering sphere is then crowned1 as with a silver halo1 by a thin luminous arch1 forming a secondary sickle facing the one nearest the sun1 and doubtless due to the refraction of his rays round the globe of the planet1 through the upper regions of her twilight atmosphere4 ,this spectacle was first observed by the ,jesuit ,ricciolo1 an opponent of the ,copernican theory1 on ,january #ith1 #afdc4 ,he describes the planet as ruddy near the sun1 yellowish in the middle1 and of greenish blue on the side remote from the sun2 while he also noted the bow of light limiting the dark hemisphere4 ,scarcely daring to trust his own eyesight1 he ascribed these appearances1 although he recorded them1 to illusory reflection in the telescope4 ,illustration3 ,,venus ,,at ,,her ,,greatest ,,brilliancy4 ,they were again seen1 however1 by ,derham about #agae1 and six years later by ,kirch1 in ,berlin1 who has the following entry in his diary for ,saturday1 ,june #bi1 #agba3--;,i found ,venus in a region where the sky was not very clear4 ,the planet was narrow1 and ,i seemed to see its dark side1 though this is almost incredible4 ,the diameter of ,venus was #fe1 and its sickle seemed to tremble in the atmospheric vapors4 ,again1 on ,march #hth1 #agbf1 he records a similar observation4 ,we observed ,venus with the twenty-six foot telescope4 ,i perceived her dark side1 and its edge seemed to describe a smaller circle than that of the light side1 as is the case of the moon4 ,this effect is due to irradiation1 that is to say1 to the glare from a bright surface1 giving a deceptive enlargement to its apparent area4 ,he again saw the dark side of the planet in ,october1 #agei1 as did ,harding at ,gttingen1 with ,herschel's ten-foot reflector1 on ,january #bdth1 #ahjf4 ,this latter observer saw it on this occasion stand out against the background of the sky as of a pale ashen green1 while on ,february #bhth following1 it seemed to him of a pale reddish gray1 like the color of the eclipsed moon4 ,that the latter body should send to us from her nocturnal shadows sufficient light to be visible is easily explicable1 since she is then flooded with earth-light reflected on her from a surface thirteen and one-half times greater than her own1 and probably casting on her an illumination transcending our full moonlight in the same proportion4 ,but the secondary light of ,venus admits of no such explanation1 since earth-light on her surface1 diminished by #a_/abjjjth part compared to what it is on that of the moon1 would be quite insufficient to render her visible to our eyes4 ,the phenomenon was therefore adduced as an argument for the habitability of the planets by ,gruithuisen1 of the ,munich ,observatory1 who1 writing early in this century1 suggested that the ashen light of ,venus might be due to general illuminations in celebration by her inhabitants of some periodically recurring festivity1 ,the materials for a flare-up on so grand a scale would1 he thought1 exist in abundance1 as he conjectured the vegetation of our planetary neighbor to be more luxuriant than that of our ,brazilian forests4 ,the phosphorescence of the ,aphroditean oceans1 warm and teeming with life1 as they are held to be by ,zollner1 was advanced as an explanatory hypothesis1 with scarcely more plausibility1 by ,professor ,safarik1 while others have resorted to the supposition of atmospheric or electrical luminosity producing on a large scale some such display as that of the aurora borealis4 ,professor ,vogel1 of ,berlin1 who himself saw part of the night-side of ,venus1 in its semi-obscurity in ,november1 #ahga1 ascribed its visibility to a twilight effect caused by a very extensive atmosphere4 ,the light thus transmitted to us by aerial diffusion and giving the ashen light1 is reflected sunlight1 while that sent by the luminous arc on its edge is direct sunlight1 refracted1 or bent round to us1 from behind the planet4 ,the silver selvedge of the dawn edging the dark limb may consequently be the brightest part of the broken nimbus that then seems to surround her4 ,a similar appearance is observed during transits of ,venus1 when she passes directly between us and the actual solar disk4 ,a silver thread is then seen encircling that side of the planet which has not yet entered on the face of the sun or a shadowy nebulous ring1 as it was described by ,mr4 ,macdonnell at ,eden1 surrounds the whole planetary disk when two-thirds of it have passed the solar edge4 ,as it moves off it1 the same aureole again becomes visible1 testifying to the existence of an atmosphere of considerable extent exterior to the sharply outlined surface ordinarily visible4 ,the shimmering haze of reflected sunlight which perpetually enfolds her is only made apparent to us under exceptional circumstances which cut off some portion of her more immediate light1 just as we see the motes in the air illuminated by a candle if we hide the actual flame from our eyes4 ,the perennial twilight which seems to reign over the nocturnal hemisphere of ,venus may compensate1 perhaps1 for the want of a satellite to modify its darkness4 ,the great prolongation at other times of the horns of her crescent1 so as to embrace almost her entire circumference with a tenuous ring of light1 is doubtless due to the same cause1 as their visibility should otherwise be limited to a half segment of a circle4 ,the regions thus shining to us are obviously those on which the sun has not yet set1 his appearance above the horizon being prolonged1 as in our own case1 by refraction1 though to a much larger extent4 ,the magnitude of the sun's disk as seen from ,venus1 a third larger than it appears to us1 is also adducted by ,mr4 ,proctor in his posthumous work1 ,the ,old and the ,new ,astronomy1 edited and completed by ,mr4 ,a4,c4 ,ranyard1 as an element in extending the illumination of ,venus to more than a hemisphere of her surface4 ,as his diameter there is #dd-a_/d1 a zone of more than #bb wide outside the sunward hemisphere is he thinks illuminated by direct though partial sunlight1 the orb being throughout this tract still partially above the horizon4 ,illustration3 ,,geographical ,,aspect ,,of ,,venus4 ,illustration ,,the ,,stars 7,,from ,,starland47 ,,by ,,sir ,,robert ,s4 ,,ball4 ,illustration ,the group of bodies which cluster around our sun forms a little island1 so to speak1 in the extent of infinite space4 ,we may illustrate this by a map in which we shall endeavor to show the stars placed at their proper relative distances4 ,we first open the compasses one inch1 and thus draw a little circle to represent the path of the earth4 ,we are not going to put in all the planets4 ,we take ,neptune1 the outermost1 at once4 ,to draw its path ,i open the compasses to thirty inches1 and draw a circle with that radius4 ,that will do for our solar system1 though the comets no doubt will roam beyond these limits4 ,to complete our map we ought of course to put in some stars4 ,there are a hundred million to choose from1 and we shall begin with the brightest4 ,it is often called the ,dog ,star1 but astronomers know it better as ,sirius4 ,let us see where it is to be placed on our map4 ,sirius is beyond ,neptune1 so it must be outside somewhere4 ,indeed1 it is a good deal further off than ,neptune2 so ,i try at the edge of the drawing-board2 ,i have got a method of making a little calculation that ,i do not intend to trouble you with1 but ,i can assure you that the results it leads me to are quite correct2 they show me that this board is not big enough4 ,but could a board which was big enough fit into this lecture theatre8 ,here1 again1 ,i make my little calculations1 and ,i find that there would not be room for a board sufficiently great2 in fact1 if ,i put the sun here at one end1 with its planets around it8 ,sirius would be too near on the same scale if it were at the further corner4 ,the board would have to go out through the wall of the theatre1 out through ,london4 ,indeed1 big as ,london is1 it would not be large enough to contain the drawing-board that ,i should require4 ,it would have to stretch about twenty miles from where we are now assembled4 ,we may therefore dismiss any hope of making a practical map of our system on this scale if ,sirius is to have its proper place4 ,let us1 then1 take some other star4 ,we shall naturally try with the nearest of all4 ,it is one that we do not know in this part of the world1 but those that live in the southern hemisphere are well acquainted with it4 ,the name of this star is ,alpha ,centauri4 ,even for this star we should require a drawing three or four miles long if the distance from the earth to the sun is to be taken as one inch4 ,you see what an isolated position our sun and his planets occupy4 ,the members of the family are all close together1 and the nearest neighbors are situated at enormous distances4 ,there is a good reason for this separation4 ,the stars are very pretty and perfectly harmless to us where they are at present situated4 ,they might be very troublesome neighbors if they were very much closer to our system4 ,it is therefore well they are so far off2 they would be constantly making disturbances in the sun's family if they were near at hand4 ,sometimes they would be dragging us into unpleasantly great heat by bringing us too close to the sun1 or producing a coolness by pulling us away from the sun1 which would be quite as disagreeable4 ,the ,stars are ,suns4 ,we are about to discuss one of the grandest truths in the whole of nature4 ,we have had occasion to see that this sun of ours is a magnificent globe immensely larger than the greatest of his planets1 while the greatest of these planets is immensely larger than this earth2 but now we are to learn that our sun is1 indeed1 only a star not nearly so bright as many of those which shine over our heads every night4 ,we are comparatively close to the sun1 so that we are able to enjoy his beautiful light and cheering heat4 ,each of those other myriads of stars is a sun1 and the splendor of those distant suns is often far greater than that of our own4 ,we are1 however1 so enormously far from them that they appear dwindled down to insignificance4 ,to judge impartially between our sun or star and such a sun or star as ,sirius we should stand halfway between the two2 it is impossible to make a fair estimate when we find ourselves situated close to one star and a million times as far from the other4 ,after allowance is made for the imperfections of our point of view1 we are enabled to realize the majestic truth that the sun is no more than a star1 and that the other stars are no less than suns4 ,this gives us an imposing idea of the extent and magnificence of the universe in which we are situated4 ,look lip at the sky at night--you will see a host of stars2 try to think that every one of them is itself a sun4 ,it may probably be that those suns have planets circling round them1 but it is hopeless for us to expect to see such planets4 ,were you standing on one of those stars and looking towards our system1 you would not perceive the sun to be the brilliant and gorgeous object that we know so well4 ,if you could see him at all1 he would merely seem like a star1 not nearly as bright as many of those you can see at night4 ,even if you had the biggest of telescopes to aid your vision1 you could never discern from one of these bodies the planets which surround the sun1 no astronomer in the stars could see ,jupiter1 even if his sight were a thousand times as powerful as any sight or telescope that we know4 ,so minute an object as our earth would1 of course1 be still more hopelessly beyond the possibility of vision4 ,the ,number of the ,stars4 ,to count the stars involves a task which lies beyond the power of man to accomplish4 ,even without the aid of any telescope1 we can see a great multitude of stars from this part of the world4 ,there are also many constellations in the southern hemisphere which never appear above our horizon4 ,if1 however1 we were to go to the equator1 then1 by waiting there for a twelve-month1 all the stars in the heavens would have been successively exposed to view4 ,an astronomer1 ,houzeau1 with the patience to count them1 enumerated about six thousand4 ,this is the naked-eye estimate of the star-population of the heavens2 but if instead of relying on unaided vision1 you get the assistance of a little telescope1 you will be astounded at the enormous multitude of stars which are disclosed4 ,illustration3 ,,fig #a4 ,,the ,,great ,,bear ,,and ,,the ,,pole4 ,an ordinary opera-glass or binocular is a very useful instrument for looking at the stars in the heavens4 ,if you employ an instrument of this sort1 you will be amazed to find that the heavens teem with additional hosts of stars that your unaided vision would never have given you knowledge of4 ,any part of the sky may be observed2 but1 just to give an illustration1 ,i shall take one special region1 namely1 that of the ,great ,bear 7,fig4 #a74 ,the seven well-known stars are here shown1 four of which form a sort of oblong1 while the other three represent the tail4 ,i would like you to make this little experiment4 ,on a fine clear night1 count how many stars there are within this oblong2 they are all very faint1 but you will be able to see a few1 and1 with good sight1 and on a clear night1 you may see perhaps ten4 ,next take your opera-glass and sweep it over the same region2 if you will carefully count the stars it shows1 you will find fully two hundred2 so that the opera-glass has1 in this part of the sky1 revealed nearly twenty times as many stars as could be seen without its aid4 ,as six thousand stars can be seen by the eye all over the heavens1 we may fairly expect that twenty times that number--that is to say1 one hundred and twenty thousand stars--could be shown by the opera-glass over the entire sky4 ,let us go a step further1 and employ a telescope1 the object-glass of which is three inches across4 ,this is a useful telescope to have1 and1 if a good one1 will show multitudes of pleasing objects1 though an astronomer would not consider it very powerful4 ,an instrument like this1 small enough to be carried in the hand1 has been applied to the task of enumerating the stars in the northern half of the sky1 and three hundred and twenty thousand stars were counted4 ,indeed1 the actual number that might have been seen with it is considerably greater1 for when the astronomer ,argelander made this memorable investigation he was unable to reckon many of the stars in localities where they lay very close together4 ,this grand count only extended to half the sky1 and1 assuming that the other half is as richly inlaid with stars1 we see that a little telescope like that we have supposed will1 when swept over the heavens1 reveal a number of stars which exceeds that of the population of any city in ,england except ,london4 ,it exhibits more than one hundred times as many stars as our eyes could possibly reveal4 ,still1 we are only at the beginning of the count2 the very great telescopes add largely to the number4 ,there are multitudes of stars which in small instruments we cannot see1 but which are distinctly visible from our great observatories4 ,that telescope would be still but a comparatively small one which would show as many stars in the sky as there are people living in the mighty city of ,london2 and with the greatest instruments1 the tale of stars has risen to a number far greater than that of the entire population of ,great ,britain4 ,in addition to those stars which the largest telescopes show us1 there are myriads which make their presence evident in a wholly different way4 ,it is only in quite recent times that an attempt has been made to develop fully the powers of photography in representing the celestial objects4 ,on a photographic plate which has been exposed to the sky in a great telescope the stars are recorded by thousands4 ,many of these may1 of course1 be observed with a good telescope1 but there are not a few others which no one ever saw in a telescope1 which apparently no one ever could see1 though the photograph is able to show them4 ,we do not1 however1 employ a camera like that which the photographer uses who is going to take your portrait4 ,the astronomer's plate is put into his telescope1 and then the telescope is turned towards the sky4 ,on that plate the stars produce their images1 each by its own light4 ,some of these images are excessively faint1 but we give a very long exposure of an hour or two hours2 sometimes as much as four hours' exposure is given to a plate so sensitive that a mere fraction of a second would sufficiently expose it during the ordinary practice of taking a photograph in daylight4 ,we thus afford sufficient time to enable the fainter objects to indicate their presence upon the sensitive film4 ,even with an exposure of a single hour a picture exhibiting sixteen thousand stars has been taken by ,mr4 ,isaac ,roberts1 of ,liverpool4 ,yet the portion of the sky which it represents is only one ten-thousandth part of the entire heavens4 ,it should be added that the region which ,mr4 ,roberts has photographed is furnished with stars in rather exceptional profusion4 ,here1 at last1 we have obtained some conception of the sublime scale on which the stellar universe is constructed4 ,yet even these plates cannot represent all the stars that the heavens contain4 ,we have every reason for knowing that with larger telescopes1 with more sensitive plates1 with more prolonged exposures1 ever fresh myriads of stars will be brought within our view4 ,you must remember that every one of these stars is truly a sun1 a lamp1 as it were1 which doubtless gives light to other objects in its neighborhood as our sun sheds light upon this earth and the other planets4 ,in fact1 to realize the glories of the heavens you should try to think that the brilliant points you see are merely the luminous points of the otherwise invisible universe4 ,standing one fine night on the deck of a ,cunarder we passed in open ocean another great ,atlantic steamer4 ,the vessel was near enough for us to see not only the light from the mast-head but also the little beams from the several cabin ports2 and we could see nothing of the ship herself4 ,her very existence was only known to us by the twinkle of these lights4 ,doubtless her passengers could see1 and did see1 the similar lights from our own vessel1 and they probably drew the correct inference that these lights indicated a great ship4 ,consider the multiplicity of beings and objects in a ship3 the captain and the crew1 the passengers1 the cabins1 the engines1 the boats1 the rigging1 and the stores4 ,think of all the varied interests there collected and then reflect that out on the ocean1 at night1 the sole indication of the existence of this elaborate structure was given by the few beams of light that happened to radiate from it4 ,now raise your eyes to the stars2 there are the twinkling lights4 ,we cannot see what those lights illuminate1 we can only conjecture what untold wealth of non-luminous bodies may also lie in their vicinity2 we may1 however1 feel certain that just as the few gleaming lights from a ship are utterly inadequate to give a notion of the nature and the contents of an ,atlantic steamer1 so are the twinkling stars utterly inadequate to give even the faintest conception of the extent and the interest of the universe4 ,we merely see self-luminous bodies1 but of the multitudes of objects and the elaborate systems of which these bodies are only the conspicuous points we see nothing and we know very little4 ,we are1 however1 entitled to infer from an examination of our own star--the sun--and of the beautiful system by which it is surrounded1 that these other suns may be also splendidly attended4 ,this is quite as reasonable a supposition as that a set of lights seen at night on the ,atlantic ,ocean indicates the existence of a fine ship4 ,the ,clusters of ,stars4 ,on a clear night you can often see1 stretching across the sky1 a track of faint light1 which is known to astronomers as the ,milky ,way4 ,it extends below the horizon1 and then round the earth to form a girdle about the heavens4 ,when we examine the ,milky ,way with a telescope we find1 to our amazement1 that it consists of myriads of stars1 so small and so faint that we are not able to distinguish them individually2 we merely see the glow produced from their collective rays4 ,remembering that our sun is a star1 and that the ,milky ,way surrounds us1 it would almost seem as if our sun were but one of the host of stars which form this cluster4 ,there are also other clusters of stars1 some of which are exquisitely beautiful telescopic spectacles4 ,i may mention a celebrated pair of these objects which lies in the constellation of ,perseus4 ,the sight of them in a great telescope is so imposing that no one who is fit to look through a telescope could resist a shout of wonder and admiration when first they burst on his view4 ,but there are other clusters4 ,here is a picture of one which is known as the ,globular ,cluster in the ,centaur 7,fig4 #b74 ,it consists of a ball of stars1 so far off that1 however large these several suns may actually be1 they have dwindled down to extremely small points of light4 ,a homely illustration may serve to show the appearance which a globular cluster presents in a good telescope4 ,i take a pepper-caster1 and on a sheet of white paper ,i begin to shake out the pepper until there is a little heap at the centre and other grains are scattered loosely about4 ,imagine that every one of those grains of pepper was to be transformed into a tiny electric light1 and then you have some idea of what a cluster of stars would look like when viewed through a telescope of sufficient power4 ,there are multitudes of such groups scattered through the depths of space4 ,they require our biggest telescopes to show them adequately4 ,we have seen that our sun is a star1 being only one of a magnificent cluster that forms the ,milky ,way4 ,we have also seen that there are other groups scattered through the length and depth of space4 ,it is thus we obtain a notion of the rank which our earth holds in the scheme of things celestial4 ,illustration3 ,,fig4 #b4 ,,globular ,,cluster ,,in ,,the ,,centaur4 ,the ,rank of the ,earth as a ,globe in ,space4 ,let me give an illustration with the view of explaining more fully the nature of the relation which the earth bears to the other globes which abound through space1 and you must allow me to draw a little upon my imagination4 ,i shall suppose that the mails of our country extend not only over this globe1 but that they also communicate with other worlds2 that postal arrangements exist between ,mars and the earth1 between the sun and ,orion--in fact1 everywhere throughout the whole extent of the universe4 ,we shall consider how our letters are to be addressed4 ,let us take the case of ,mr4 ,john ,smith1 merchant1 who lives at #ajja1 ,piccadilly2 and let us suppose that ,mr4 ,john ,smith's business transactions are of such an extensive nature that they reach not only all over this globe1 but away throughout space4 ,i shall suppose that the firm has a correspondent residing--let us say in the constellation of the ,great ,bear2 and when this man of business wants to write to ,mr4 ,smith from these remote regions1 what address must he put upon the letter1 so that the ,postmaster-,general of the universe shall make no mistake about its delivery8 ,he will write as follows3-- ,,mr4 ,,john ,,smith1 #ajja ,piccadilly1 ,london1 ,england1 ,europe1 ,earth1 ,near the ,sun1 ,milky ,way1 ,the ,universe4 ,let us now see what the several lines of this address mean4 ,of course we put down the name of ,mr4 ,john ,smith in the first line1 and then we will add #ajja ,piccadilly for the second2 but as the people in the ,great ,bear are not likely to know where ,piccadilly is1 we shall add ,london underneath4 ,as even ,london itself cannot be well known everywhere1 it is better to write ,england4 ,this would surely find ,mr4 ,john ,smith from any post-office on this globe4 ,from other globes1 however1 the supreme importance of ,england may not be so immediately recognized1 and therefore it is as well to add another line1 ,europe4 ,this ought to be sufficient1 ,i think1 for any post-office in the solar system4 ,europe is big enough to be visible from ,mars or ,venus1 and should be known to the post-office people there1 just as we know and have names for the continents on ,mars4 ,but further away there might be a little difficulty2 from ,uranus and ,neptune the different regions on our earth can never have been distinguished1 and therefore we must add another line to indicate the particular globe of the solar system which contains ,europe4 ,mark ,twain tells us that there was always one thing in astronomy which specially puzzled him1 and that was to know how we found out the names of the stars4 ,we are1 of course1 in hopeless ignorance of the name by which this earth is called among other intelligent beings elsewhere who can see it4 ,i can only adopt the title of ,earth1 and therefore ,i add this line4 ,now our address is so complete that from anywhere in the solar system--from ,mercury1 from ,jupiter1 or ,neptune--there ought to be no mistake about the letter finding its way to ,mr4 ,john ,smith4 ,but from his correspondent in the ,great ,bear this address would be still incomplete2 they cannot see our earth from there1 and even the sun himself only looks like a small star--like one1 in fact1 of thousands of stars elsewhere4 ,however1 each star can be distinguished1 and our sun may1 for instance1 be recognized from the ,great ,bear by some designation4 ,we shall add the line ,near the ,sun1 and then ,i think that from this constellation1 or from any of the other stars around us1 the address of ,mr4 ,john ,smith may be regarded as complete4 ,but ,mr4 ,smith's correspondence may be still wider4 ,he may have an agent living in the cluster of ,perseus or on some other objects still fainter and more distant2 then ,near the ,sun is utterly inadequate as a concluding line to the address1 for the sun1 if it can be seen at all from thence1 will be only of the significance of an excessively minute star1 no more to be designated by a special name than are each of the several leaves on the trees of a forest4 ,what this distant correspondent will be acquainted with is not the earth or the sun but only the cluster of stars among which the sun is but a unit4 ,again we use our own name to denote the cluster1 and we call it the ,milky ,way4 ,when we add this line1 we have made the address of ,mr4 ,john ,smith as complete as circumstances will permit4 ,i think a letter posted to him anywhere ought to reach its destination4 ,to perfect it1 however1 we will finish up with one line more--,the ,universe4 ,the ,distances of the ,stars4 ,i must now tell you something about the distances of the stars4 ,i shall not make the attempt to explain fully how astronomers make such measurements1 but ,i will give you some notion of how it is done4 ,you may remember ,i showed you how we found the distance of a globe that was hung from the ceiling4 ,the principle of the method for finding the distance of a star is somewhat similar1 except that we make the two observations not from the two ends of a table1 not even from opposite sides of the earth1 but from two opposite points on the earth's orbit1 which are therefore at a distance of one hundred and eighty-six million miles4 ,imagine that on ,midsummer ,day1 when standing on the earth here1 ,i measure with a piece of card the angle between the star and the sun4 ,six months later1 on ,midwinter ,day1 when the earth is at the opposite point of its orbit1 ,i again measure the angle between the same star and the sun1 and we can now determine the star's distance by making a triangle4 ,i draw a line a foot long1 and we will take this foot to represent one hundred and eighty-six million miles1 the distance between the two stations2 then placing the cards at the corners1 ,i rule the two sides and complete the triangle1 and the star must be at the remaining corner2 then ,i measure the sides of the triangle1 and how many feet they contain1 and recollecting that each foot corresponds to one hundred and eighty-six million miles1 we discover the distance of the star4 ,if the stars were comparatively near us1 the process would be a very simple one2 but1 unfortunately1 the stars are so extremely far off that this triangle1 even with a base of only one foot1 must have its sides many miles long4 ,indeed1 astronomers will tell you that there is no more delicate or troublesome work in the whole of their science than that of discovering the distance of a star4 ,in all such measurements we take the distance from the earth to the sun as a conveniently long measuring-rod1 whereby to express the results4 ,the nearest stars are still hundreds of thousands of times as far off as the sun4 ,let us ponder for a little on the vastness of these distances4 ,we shall first express them in miles4 ,taking the sun's distance to be ninety-three million miles1 then the distance of the nearest fixed star is about twenty millions of millions of miles--that is to say1 we express this by putting down a #b first1 and then writing thirteen ciphers after it4 ,it is1 no doubt1 easy to speak of such figures1 but it is a very different matter when we endeavor to imagine the awful magnitude which such a number indicates4 ,i must try to give some illustrations which will enable you to form a notion of it4 ,at first ,i was going to ask you to try and count this number1 but when ,i found it would require at least three hundred thousand years1 counting day and night without stopping1 before the task was over1 it became necessary to adopt some other method4 ,when on a visit in ,lancashire ,i was once kindly permitted to visit a cotton mill1 and ,i learned that the cotton yarn there produced in a single day would be long enough to wind round this earth twenty-seven times at the equator4 ,it appears that the total production of cotton yarn each day in all the mills together would be on the average about one hundred and fifty-five million miles4 ,in fact1 if they would only spin about one-fifth more1 we could assert that ,great ,britain produced enough cotton yarn every day to stretch from the earth to the sun and back again6 ,it is not hard to find from these figures how long it would take for all the mills in ,lancashire to produce a piece of yarn long enough to reach from our earth to the nearest of the stars4 ,if the spinners worked as hard as ever they could for a year1 and if all the pieces were then tied together1 they would extend to only a small fraction of the distance2 nor if they worked for ten years1 or for twenty years1 would the task be fully accomplished4 ,indeed1 upwards of four hundred years would be necessary before enough cotton could be grown in ,america and spun in this country to stretch over a distance so enormous4 ,all the spinning that has ever yet been done in the world has not formed a long enough thread6 ,there is another way in which we can form some notion of the immensity of these sidereal distances4 ,you will recollect that1 when we were speaking of ,jupiter's moons1 ,i told you of the beautiful discovery which their eclipses enabled astronomers to make4 ,it was thus found that light travels at the enormous speed of about one hundred and eighty-five thousand miles per second4 ,it moves so quickly that within a single second a ray would flash two hundred times from ,london to ,edinburgh and back again4 ,we said that a meteor travels one hundred times as swiftly as a rifle-bullet2 but even this great speed seems almost nothing when compared with the speed of light1 which is ten thousand times as great4 ,suppose some brilliant outbreak of light were to take place in a distant star--an outbreak which would be of such intensity that the flash from it would extend far and wide throughout the universe4 ,the light would start forth on its voyage with terrific speed4 ,any neighboring star which was at a distance of less than one hundred and eighty-five thousand miles would1 of course1 see the flash within a second after it had been produced4 ,more distant bodies would receive the intimation after intervals of time proportioned to their distances4 ,thus1 if a body were one million miles away1 the light would reach it in from five to six seconds1 while over a distance as great as that which separates the earth from the sun the news would be carried in about eight minutes4 ,we can calculate how long a time must elapse ere the light shall travel over a distance so great as that between the star and our earth4 ,you will find that from the nearest of the stars the time required for the journey will be over three years4 ,ponder on all that this involves4 ,that outbreak in the star might be great enough to be visible here1 but we could never become aware of it till three years after it had happened4 ,when we are looking at such a star to-night we do not see it as it is at present1 for the light that is at this moment entering our eyes has travelled so far that it has been three years on the way4 ,therefore1 when we look at the star now we see it as it was three years previously4 ,in fact1 if the star were to go out altogether1 we might still continue to see it twinkling for a period of three years longer1 because a certain amount of light was on its way to us at the moment of extinction1 and so long as that light keeps arriving here1 so long shall we see the star showing as brightly as ever4 ,when1 therefore1 you look at the thousands of stars in the sky to-night1 there is not one that you see as it is now1 but as it was years ago4 ,i have been speaking of the stars that are nearest to us1 but there are others much farther off4 ,it is true we cannot find the distances of these more remote objects with any degree of accuracy1 but we can convince ourselves how great that distance is by the following reasoning4 ,look at one of the brightest stars4 ,try to conceive that the object was carried away further into the depths of space1 until it was ten times as far from us as it is at present1 it would still remain bright enough to be recognized in quite a small telescope2 even if it were taken to one hundred times its original distance it would not have withdrawn from the view of a good telescope2 while if it retreated one thousand times as far as it was at first it would still be a recognizable point in our mightiest instruments4 ,among the stars which we can see with our telescopes1 we feel confident there must be many from which the light has expended hundreds of years1 or even thousands of years1 on the journey4 ,when1 therefore1 we look at such objects1 we see them1 not as they are now1 but as they were ages ago2 in fact1 a star might have ceased to exist for thousands of years1 and still be seen by us every night as a twinkling point in our great telescopes4 ,remembering these facts1 you will1 ,i think1 look at the heavens with a new interest4 ,there is a bright star1 ,vega1 or ,alpha ,lyr1 a beautiful gem1 so far off that the light from it which now reaches our eyes started before many of my audience were born4 ,suppose that there are astronomers residing on worlds amid the stars1 and that they have sufficiently powerful telescopes to view this globe1 what do you think they would observe8 ,they will not see our earth as it is at present2 they will see it as it was years 7and sometimes many years7 ago4 ,there are stars from which if ,england could now be seen1 the whole of the country would be observed at this present moment to be in a great state of excitement at a very auspicious event4 ,distant astronomers might notice a great procession in ,london1 and they could watch the coronation of a youthful queen amid the enthusiasm of a nation4 ,there are other stars still further1 from which1 if the inhabitants had good enough telescopes1 they would now see a mighty battle in progress not far from ,brussels4 ,one splendid army could be beheld hurling itself time after time against the immovable ranks of the other4 ,they would not1 indeed1 be able to hear the ever-memorable ,up1 ,guards1 and at them6 but there can be no doubt that there are stars so far away that the rays of light which started from the earth on the day of the battle of ,waterloo are only just arriving there4 ,further off still1 there are stars from which a bird's-eye view could be taken at this very moment of the signing of ,magna ,charta4 ,there are even stars from which ,england1 if it could be seen at all1 would now appear1 not as the great ,england we know1 but as a country covered by dense forests1 and inhabited by painted savages1 who waged incessant war with wild beasts that roamed through the island4 ,the geological problems that now puzzle us would be quickly solved could we only go far enough into space and had we only powerful enough telescopes4 ,we should then be able to view our earth through the successive epochs of past geological time2 we should be actually able to see those great animals whose fossil remains are treasured in our museums tramping about over the earth's surface1 splashing across its swamps1 or swimming with broad flippers through its oceans4 ,indeed1 if we could view our own earth reflected from mirrors in the stars1 we might still see ,moses crossing the ,red ,sea1 or ,adam and ,eve being expelled from ,eden4 ,so important is the subject of star distance that ,i am tempted to give one more illustration in order to bring before you some conception of how vast such distances are4 ,i shall take1 as before1 the nearest of the stars so far as known to us1 and ,i hope to be forgiven for taking an illustration of a practical and a commercial kind instead of one more purely scientific4 ,i shall suppose that a railway is about to be made from ,london to ,alpha ,centauri4 ,the length of that railway1 of course1 we have already stated3 it is twenty billions of miles4 ,so ,i am now going to ask your attention to the simple question as to the fare which it would be reasonable to charge for the journey4 ,we shall choose a very cheap scale on which to compute the price of a ticket4 ,the parliamentary rate here is1 ,i believe1 a penny for every mile4 ,we will make our interstellar railway fares much less even than this2 we shall arrange to travel at the rate of one hundred miles for every penny4 ,that1 surely1 is moderate enough4 ,if the charges were so low that the journey from ,london to ,edinburgh only cost fourpence1 then even the most unreasonable passenger would be surely contented4 ,on these terms how much do you think the fare from ,london to this star ought to be8 ,i know of one way in which to make our answer intelligible4 ,there is a ,national ,debt with which your fathers are1 unhappily1 only too well acquainted2 you will know quite enough about it yourselves in those days when you have to pay income tax4 ,this debt is so vast that the interest upon it is about sixty thousand pounds a day1 the whole amount of the ,national ,debt being six hundred and thirty-eight millions of pounds4 ,if you went to the booking-office with the whole of this mighty sum in your pocket--but stop a moment2 could you carry it in your pocket8 ,certainly not1 if it were in sovereigns4 ,you would find that after you had as many sovereigns as you could conveniently carry there would still be some left--so many1 indeed1 that it would be necessary to get a cart to help you on with the rest4 ,when the cart had as great a load of sovereigns as the horse could draw there would be still some more1 and you would have to get another cart2 but ten carts1 twenty carts1 fifty carts1 would not be enough4 ,you would want five thousand of these before you would be able to move off towards the station with your money4 ,when you did get there and asked for a ticket at the rate of one hundred miles for a penny1 do you think you would get any change8 ,no doubt some little time would be required to count the money1 but when it was counted the clerk would tell you that there was not enough--that he must have nearly two hundred millions of pounds more4 ,that will give some notion of the distance of the nearest star1 and we may multiply it by ten1 by one hundred1 and even by one thousand1 and still not attain to the distance of some of the more remote stars that the telescope shows us4 ,on account of the immense distances of the stars we can only perceive them to be mere points of light4 ,we can never see a star to be a globe with marks on it like the moon1 or like one of the planets--in fact1 the better the telescope the smaller does the star seem1 though1 of course1 its brightness is increased with every addition to the light-grasping power of the instrument4 ,the ,brightness and ,color of ,stars4 ,another point to be noticed is the arrangement of stars in classes1 according to their lustre4 ,the brightest stars1 of which there are about twenty1 are said to be of the first magnitude4 ,those just inferior to the first magnitude are ranked as the second2 and those just lower than the second are estimated as the third2 and so on4 ,the smallest points that your unaided eyes will show you are of about the sixth magnitude4 ,then the telescope will reveal stars still fainter and fainter1 down to what we term the seventeenth or eighteenth magnitudes1 or even lower still4 ,the number of stars of each magnitude increases very much in the classes of small ones4 ,most of the stars are white1 but many are of a somewhat ruddy hue4 ,there are a few telescopic points which are intensely red1 some exhibit beautiful golden tints1 while others are blue or green4 ,there are some curious stars which regularly change their brilliancy4 ,let me try to illustrate the nature of these variables4 ,suppose that you were looking at a street gas-lamp from a very long distance1 so that it seemed a little twinkling light2 and suppose that some one was preparing to turn the gas-cock up and down4 ,or1 better still1 imagine a little machine which would act regularly so as to keep the light first of all at its full brightness for two days and a half1 and then gradually turn it down until in three or four hours it declines to a feeble glimmer4 ,in this low state the light remains for twenty minutes2 then during three or four hours the gas is to be slowly turned on again until it is full4 ,in this condition the light will remain for two days and a half1 and then the same series of changes is to recommence4 ,this would be a very odd form of gas-lamp4 ,there would be periods of two days and a half during which it would remain at its full2 these would be separated by intervals of about seven hours1 when the gradual turning down and turning up again would be in progress4 ,the imaginary gas-lamp is exactly paralleled by a star ,algol1 in the constellation of ,perseus 7,fig4 #c71 which goes through the series of changes ,i have indicated4 ,ordinarily speaking1 it is a bright star of the second magnitude1 and1 whatever be the cause1 the star performs its variations with marvellous uniformity4 ,in fact1 ,algol has always arrested the attention of those who observed the heavens1 and in early times was looked on as the eye of a demon4 ,there are many other stars which also change their brilliancy4 ,most of them require much longer periods than ,algol1 and sometimes a new star which nobody has ever seen before will suddenly kindle into brilliancy4 ,it is now known that the bright star ,algol is attended by a dark companion4 ,this dark star sometimes comes between ,algol and the observer and cuts off the light4 ,thus it is that the diminution of brightness is produced4 ,illustration3 ,,fig4 #c4 ,,perseus ,,and ,,its ,,neighboring ,,stars ,,including ,,algol4 ,double ,stars4 ,whenever you have a chance of looking at the heavens through a telescope1 you should ask to be shown what is called a double star4 ,there are many stars in the heavens which present no remarkable appearance to the unaided eye1 but which a good telescope at once shows to be of quite a complex nature4 ,these are what we call double stars1 in which two quite distinct stars are placed so close together that the unaided eye is unable to separate them4 ,under the magnifying power of the telescope1 however1 they are seen to be distinct4 ,in order to give some notion of what these objects are like1 ,i shall briefly describe three of them4 ,the first lies in that best known constellation1 the ,great ,bear4 ,if you look at his tail1 which consists of three stars1 you will see that near the middle one of the three a small star is situated2 we call this little star ,alcor1 but it is the brighter one near ,alcor to which ,i specially call your attention4 ,the sharpest eye would never suspect that it was composed of two stars placed close together4 ,even a small telescope will1 however1 show this to be the case1 and this is the easiest and the first observation that a young astronomer should make when beginning to turn a telescope to the heavens4 ,of course you will not imagine that ,i mean ,alcor to be the second component of the double star2 it is the bright star near ,alcor which is the double4 ,here are two marbles1 and these marbles are fastened an inch apart4 ,you can see them1 of course1 to be separate2 but if the pair were moved further and further away1 then you would soon not be able to distinguish between them1 though the actual distance between the marbles had not altered4 ,look at these two wax tapers which are now lighted2 the little flames are an inch apart4 ,you would have to view them from a station a third of a mile away if the distance between the two flames were to appear the same as that between the two components of this double star4 ,your eye would never be able to discriminate between two lights only an inch apart at so great a distance2 a telescope would1 however1 enable you to do so1 and this is the reason why we have to use telescopes to show us double stars4 ,you might look at that double star year after year throughout the course of a long life without finding any appreciable change in the relative positions of its components4 ,but we know that there is no such thing as rest in the universe2 even if you could balance a body so as to leave it for a moment at rest1 it would not stay there1 for the simple reason that all the bodies round it in every direction are pulling at it1 and it is certain that the pull in one direction will preponderate1 so that move it must4 ,especially is this true in the case of two suns like those forming a double star4 ,placed comparatively near each other they could not remain permanently in that position2 they must gradually draw together and come into collision with an awful crash4 ,there is only one way by which such a disaster could be averted4 ,that is by making one of these stars revolve around the other just as the earth revolves around the sun1 or the moon revolves around the earth4 ,some motion must1 therefore1 be going on in every genuine double star1 whether we have been able to see that motion or not4 ,let us now look at another double star of a different kind4 ,this time it is in the constellation of ,gemini4 ,the heavenly twins are called ,castor and ,pollux4 ,of these1 ,castor is a very beautiful double star1 consisting of two bright points1 a great deal closer together than were those in the ,great ,bear2 consequently a better telescope is required for the purpose of showing them separately4 ,castor has been watched for many years1 and it can be seen that one of these stars is slowly revolving around the other2 but it takes a very long time1 amounting to hundreds of years1 for a complete circuit to be accomplished4 ,this seems very astonishing1 but when you remember how exceedingly far ,castor is1 you will perceive that that pair of stars which appear so close together that it requires a telescope to show them apart must indeed be separated by hundreds of millions of miles4 ,let us try to conceive our own system transformed into a double star4 ,if we took our outermost planet--,neptune--and enlarged him a good deal1 and then heated him sufficiently to make him glow like a sun1 he would still continue to revolve round our sun at the same distance1 and thus a double star would be produced4 ,an inhabitant of ,castor who turned his telescope towards us would be able to see the sun as a star4 ,he would not1 of course1 be able to see the earth1 but he might see ,neptune like another small star close to the sun4 ,if generations of astronomers in ,castor continued their observations of our system1 they would find a binary star1 of which one component took a century and a half to go round the other4 ,need we then be surprised that when we look at ,castor we observe movements that seem very slow8 ,there is often so much diffused light about the bright stars seen in a telescope1 and so much twinkling in some states of the atmosphere1 that stars appear to dance about in rather a puzzling fashion1 especially to one who is not accustomed to astronomical observations4 ,i remember hearing how a gentleman once came to visit an observatory4 ,the astronomer showed him ,castor through a powerful telescope as a fine specimen of a double star1 and then1 by way of improving his little lesson1 the astronomer mentioned that one of these stars was revolving around the other4 ,oh1 yes1 said the visitor1 ,i saw them going round and round in the telescope4 ,he would1 however1 have had to wait for a few centuries with his eye to the instrument before he would have been entitled to make this assertion4 ,double stars also frequently delight us by giving beautifully contrasted colors4 ,i dare say you have often noticed the red and the green lights that are used on railways in the signal lamps4 ,imagine one of those red and one of those green lights away far up in the sky and placed close together1 then you would have some idea of the appearance that a colored double star presents1 though1 perhaps1 ,i should add that the hues in the heavenly bodies are not so vividly different as are those which our railway people find necessary4 ,there is a particularly beautiful double star of this kind in the constellation of the ,swan4 ,you could make an imitation of it by boring two holes1 with a red-hot needle1 in a piece of card1 and then covering one of these holes with a small bit of the topaz-colored gelatine with which ,christmas crackers are made4 ,the other star is to be similarly colored with blue gelatine4 ,a slide made on this principle placed in the lantern gives a very good representation of these two stars on the screen4 ,there are many other colored doubles besides this one2 and1 indeed1 it is noteworthy that we hardly ever find a blue or a green star by itself in the sky2 it is always as a member of one of these pairs4 ,how ,we ,find ,what the ,stars are ,made of4 ,here is a piece of stone4 ,if ,i wanted to know what it was composed of1 ,i should ask a chemist to tell me4 ,he would take it into his laboratory1 and first crush it into powder1 and then1 with his test tubes1 and with the liquids which his bottles contain1 and his weighing scales1 and other apparatus1 he would tell all about it2 there is so much of this1 and so much of that1 and plenty of this1 and none at all of that4 ,but now1 suppose you ask this chemist to tell you what the sun is made of1 or one of the stars4 ,of course1 you have not a sample of it to give him2 how1 then1 can he possibly find out anything about it8 ,well1 he can tell you something1 and this is the wonderful discovery that ,i want to explain to you4 ,we now put down the gas1 and ,i kindle a brilliant red light4 ,perhaps some of those whom ,i see before me have occasionally ventured on the somewhat dangerous practice of making fire-works4 ,if there is any boy here who has ever constructed sky-rockets1 and put the little balls into the top which are to burn with such vivid colors when the explosion takes place1 he will know that the substance which tinged that fire red must have been strontium4 ,he will recognize it by the color2 because strontium gives a red light which nothing else will give4 ,here are some of these lightning papers1 as they are called2 they are very pretty and very harmless2 and these1 too1 give brilliant red flashes as ,i throw them4 ,the red tint has1 no doubt1 been produced by strontium also4 ,you see we recognized the substance simply by the color of the light it produced when burning4 ,perhaps some of you have tried to make a ghost at ,christmas by dressing up in a sheet1 and bearing in your hand a ladle blazing with a mixture of common salt and spirits of wine1 the effect produced being a most ghastly one4 ,some mammas will hardly thank me for this suggestion1 unless ,i add that the ghost must walk about cautiously1 for otherwise the blazing spirit would be very apt to produce conflagrations of a kind more extensive than those intended4 ,however1 by the kindness of ,professor ,dewar1 ,i am enabled to show the phenomenon on a splendid scale1 and also free from all danger4 ,i kindle a vivid flame of an intensely yellow color1 which ,i think the ladies will unanimously agree is not at all becoming to their complexions1 while the pretty dresses have lost their variety of colors4 ,here is a nice bouquet1 and yet you can hardly distinguish the green of the leaves from the brilliant colors of the flowers1 except by trifling differences of shade4 ,expose to this light a number of pieces of variously colored ribbon1 pink and red and green and blue1 and their beauty is gone2 and yet we are told that this yellow is a perfectly pure color2 in fact1 the purest color that can be produced4 ,i think we have to be thankful that the light which our good sun sends us does not possess purity of that description4 ,there is one substance which will produce that yellow light2 it is a curious metal called sodium--a metal so soft that you can cut it with a knife1 and so light that it will float on water2 while1 still more strange1 it actually takes fire the moment it is dropped on the water4 ,it is only in a chemical laboratory that you will be likely to meet with the actual metallic sodium1 yet in other forms the substance is one of the most abundant in nature4 ,indeed1 common salt is nothing but sodium closely united with a most poisonous gas1 a few respirations of which would kill you4 ,but this strange metal and this noxious gas1 when united1 become simply the salt for our eggs at breakfast4 ,this pure yellow light1 wherever it is seen1 either in the flame of spirits of wine mixed with salt or in that great blaze at which we have been looking1 is characteristic of sodium4 ,wherever you see that particular kind of light1 you know that sodium must have been present in the body from which it came4 ,we have accordingly learned to recognize two substances1 namely1 strontium and sodium1 by the different lights which they give out when burning4 ,to these two metals we may add a third4 ,here is a strip of white metallic ribbon4 ,it is called magnesium4 ,it seems like a bit of tin at the first glance1 but indeed it is a very different substance from tin2 for1 look1 when ,i hold it in the spirit-lamp1 the strip of metal immediately takes fire1 and burns with a white light so dazzling that it pales the gas-flames to insignificance4 ,there is no other substance which will1 when kindled1 give that particular kind of light which we see from magnesium4 ,i can recommend this little experiment as quite suitable for trying at home2 you can buy a bit of magnesium ribbon for a trifle at the opticians2 it cannot explode or do any harm1 nor will you get into any trouble with the authorities provided you hold it when burning over a tray or a newspaper1 so as to prevent the white ashes from falling on the carpet4 ,there are1 in nature1 a number of simple bodies called elements4 ,every one of these1 when ignited under suitable conditions1 emits a light which belongs to it alone1 and by which it can be distinguished from every other substance4 ,i do not say that we can try the experiments in the simple way ,i have here indicated4 ,many of the materials will yield light which will require to be studied by much more elaborate artifices than those which have sufficed for us4 ,but you will see that the method affords a means of finding out the actual substances present in the sun or in the stars4 ,there is a practical difficulty in the fact that each of the heavenly bodies contains a number of different elements2 so that in the light it sends us the hues arising from distinct substances are blended into one beam4 ,the first thing to be done is to get some way of splitting up a beam of light1 so as to discover the components of which it is made4 ,you might have a skein of silks of different hues tangled together1 and this would be like the sunbeam as we receive it in its unsorted condition4 ,how shall we untangle the light from the sun or a star8 ,i will show you by a simple experiment4 ,here is a beam from the electric light2 beautifully white and bright1 is it not8 ,it looks so pure and simple1 but yet that beam is composed of all sorts of colors mingled together1 in such proportions as to form white light4 ,i take a wedge-shaped piece of glass called a prism1 and when ,i introduce it into the course of the beam1 you see the transformation that has taken place 7,fig4 #d74 ,instead of the white light you have now all the colors of the rainbow--red1 orange1 yellow1 green1 blue1 indigo1 violet1 marked by their initial letters in the figure4 ,these colors are very beautiful1 but they are transient1 for the moment we take away the prism they all unite again to form white light4 ,you see what the prism has done2 it has bent all the light in passing through it2 but it is more effective in bending the blue than the red1 and consequently the blue is carried away much further than the red4 ,such is the way in which we study the composition of a heavenly body4 ,we take a beam of its light1 we pass it through a prism1 and immediately it is separated into its components2 then we compare what we find with the lights given by the different elements1 and thus we are enabled to discover the substances which exist in the distant object whose light we have examined4 ,i do not mean to say that the method is a simple one2 all ,i am endeavoring to show is a general outline of the way in which we have discovered the materials present in the stars4 ,the instrument that is employed for this purpose is called the spectroscope4 ,and perhaps you may remember that name by these lines1 which ,i have heard from an astronomical friend3-- ,twinkle1 twinkle1 little star1 ,now we find out what you are1 ,when unto the midnight sky1 ,we the spectroscope apply4 ,illustration3 ,,fig4 #d4 ,,how ,a ,,ray ,,of ,,light ,,is ,,split ,,up4 ,i am sure it will interest everybody to know that the elements which the stars contain are not altogether different from those of which the earth is made4 ,it is true there may be substances in the stars of which we know nothing here2 but it is certain that many of the most common elements on the earth are present in the most distant bodies4 ,i shall only mention one1 the metal iron4 ,that useful substance has been found in some of the stars which lie at almost incalculable distances from the earth4 ,the ,nebul4 ,in drawing towards the close of these lectures ,i must say a few words about some dim and mysterious objects to which we have not yet alluded4 ,they are what are called nebul1 or little clouds2 and in one sense they are justly called little1 for each of them occupies but a very small spot in the sky as compared with that which would be filled by an ordinary cloud in our air4 ,the nebul are1 however1 objects of the most stupendous proportions4 ,were our earth and thousands of millions of bodies quite as big all put together1 they would not be nearly so great as one of these nebul4 ,astronomers reckon up the various nebul by thousands1 but ,i must add that most of them are apparently faint and uninteresting4 ,a nebula is sometimes liable to be mistaken for a comet4 ,the comet is1 as ,i have already explained1 at once distinguished by the fact that it is moving and changing its appearance from hour to hour1 while scores of years elapse without changes in the aspect or position of a nebula4 ,the most powerful telescopes are employed in observing these faint objects4 ,i take this opportunity of showing a picture of an instrument suitable for such observations4 ,it is the great reflector of the ,paris ,observatory 7,fig4 #e74 ,illustration3 ,,fig4 #e4 ,a ,,great ,,reflecting ,,telescope4 ,illustration3 ,,fig4 #f4 ,,the ,,ring ,,nebula ,,in ,,lyra1 ,,under ,,different ,,telescopic ,,powers4 ,there are such multitudes of nebul that ,i can only show a few of the more remarkable kinds4 ,in ,fig4 #f will be seen pictures of a curious object in the constellation of ,lyra seen under different telescopic powers4 ,this is a gigantic ring of luminous gas4 ,to judge of the size of this ring let us suppose that a railway were laid across it1 and the train you entered at one side was not to stop until it reached the other side1 how long do you think this journey would require8 ,i recollect some time ago a picture in ,punch which showed a train about to start from ,london to ,brighton1 and the guard walking up and down announcing to the passengers the alarming fact that this train stops nowhere4 ,an old gentleman was seen vainly gesticulating out of the window and imploring to be let out ere the frightful journey was commenced4 ,in the nebular railway the passengers would almost require such a warning4 ,let the train start at a speed of a mile a minute1 you would think1 surely1 that it must soon cross the ring4 ,but the minutes pass1 an hour has elapsed2 so the distance must be sixty miles at all events4 ,the hours creep on into days1 the days advance into years1 and still the train goes on4 ,the years would lengthen out into centuries1 and even when the train had been rushing on for a thousand years with an unabated speed of a mile a minute1 the journey would certainly not have been completed4 ,nor do ,i venture to say what ages must elapse ere the terminus at the other side of the ring nebula would be reached4 ,a cluster of stars viewed in a small telescope will often seem like a nebula1 for the rays of the stars become blended4 ,a powerful telescope will1 however1 dispel the illusion and reveal the separate stars4 ,it was1 therefore1 thought that all the nebul might be merely clusters so exceedingly remote that our mightiest instruments failed to resolve them into stars4 ,but this is now known not to be the case4 ,many of these objects are really masses of glowing gas2 such are1 for instance1 the ring nebul1 of which ,i have just spoken1 and the form of which ,i can simulate by a pretty experiment4 ,we take a large box with a round hole cut in one face1 and a canvas back at the opposite side4 ,i first fill this box with smoke1 and there are different ways of doing so4 ,burning brown paper does not answer well1 because the supply of smoke is too irregular and the paper itself is apt to blaze4 ,a little bit of phosphorus set on fire yields copious smoke1 but it would be apt to make people cough1 and1 besides1 phosphorus is a dangerous thing to handle incautiously1 and ,i do not want to suggest anything which might be productive of disaster if the experiment was repeated at home4 ,a little wisp of hay1 slightly damped and lighted1 will safely yield a sufficient supply1 and you need not have an elaborate box like this2 any kind of old packing-case1 or even a bandbox with a duster stretched across its open top and a round hole cut in the bottom1 will answer capitally4 ,while ,i have been speaking1 my assistant has kindly filled this box with smoke1 and in order to have a sufficient supply1 and one which shall be as little disagreeable as possible1 he has mixed together the fumes of hydrochloric acid and ammonia from two retorts shown in ,fig4 #g4 ,a still simpler way of doing the same thing is to put a little common salt in a saucer and pour over it a little oil of vitriol2 this is put into the box1 and over the floor of the box common smelling-salts is to be scattered4 ,you see there are dense volumes of white smoke escaping from every corner of the box4 ,i uncover the opening and give a push to the canvas1 and you see a beautiful ring flying across the room2 another ring and another follows4 ,if you were near enough to feel the ring1 you would experience a little puff of wind2 ,i can show this by blowing out a candle which is at the other end of the table4 ,these rings are made by the air which goes into a sort of eddy as it passes through the hole4 ,all the smoke does is to render the air visible4 ,the smoke-ring is indeed quite elastic4 ,if we send a second ring hurriedly after the first1 we can produce a collision1 and you see each of the two rings remains unbroken1 though both are quivering from the effects of the blow4 ,they are beautifully shown along the beam of the electric lamp1 or1 better still1 along a sunbeam4 ,illustration3 ,,fig4 #g4 ,,how ,,to ,,make ,,the ,,smoke ,,rings4 ,we can make many experiments with smoke-rings4 ,here1 for instance1 ,i take an empty box1 so far as smoke is concerned1 but air-rings can be driven forth from it1 though you cannot see them1 but you can feel them even at the other side of the room1 and they will1 as you see1 blow out a candle4 ,i can also shoot invisible air-rings at a column of smoke1 and when the missile strikes the smoke it produces a little commotion and emerges on the other side1 carrying with it enough of the smoke to render itself visible1 while the solid black looking ring of air is seen in the interior4 ,still more striking is another way of producing these rings1 for ,i charge this box with ammonia1 and the rings from it you cannot see4 ,there is a column of the vapor of hydrochloric acid1 that also you cannot see2 but when the visible ring enters the invisible column1 then a sudden union takes place between the vapor of the ammonia and the vapor of the hydrochloric acid2 the result is a solid white substance in extremely fine dust which renders the ring instantly visible4 ,what the ,nebul are made of4 ,there is a fundamental difference between the illumination of these little rings that ,i have shown you and the great rings in the heavens4 ,i had to illuminate our smoke with the help of the electric light1 for1 unless ,i had done so1 you would not have been able to see them4 ,this white substance formed by the union of ammonia and hydrochloric acid has1 of course1 no more light of its own than a piece of chalk2 it requires other light falling upon it to make it visible4 ,were the ring nebula in ,lyra composed of this material1 we could not see it4 ,the sunlight which illuminates the planets might1 of course1 light up such an object as the ring1 if it wrere comparatively near us2 but ,lyra is at such a stupendous distance that any light which the sun could send out there would be just as feeble as the light we receive from a fixed star4 ,should we be able to show our smoke-rings1 for instance1 if1 instead of having the electric light1 ,i merely cut a hole in the ceiling and allowed the feeble twinkle of a star in the ,great ,bear to shine through8 ,in a similar way the sunbeams would be utterly powerless to effect any illumination of objects in these stellar distances4 ,if the sun were to be extinguished altogether1 the calamity would no doubt be a very dire one so far as we are concerned1 but the effect on the other celestial bodies 7moon and planets excepted7 would be of the slightest possible description4 ,all the stars of heaven would continue to shine as before4 ,not a point in one of the constellations wrould be altered1 not a variation in the brightness1 not a change in the hue of any star could be noticed4 ,the thousands of nebul and clusters would be absolutely unaltered2 in fact1 the total extinction of the sun would be hardly remarked in the newspapers published in the ,pleiades or in ,orion4 ,there might possibly be a little line somewhere in an odd corner to the effect ,mr4 ,so-and-,so1 our well-known astronomer1 has noticed that a tiny star1 inconspicuous to the eye1 and absolutely of no importance whatever1 has now become invisible4 ,if1 therefore1 it be not the sun which lights up this nebula1 where else can be the source of its illumination8 ,there can be no other star in the neighborhood adequate to the purpose1 for1 of course1 such an object would be brilliant to us if it were large enough and bright enough to impart sufficient illumination to the nebula4 ,it would be absurd to say that you could see a man's face by the light of a candle while the candle itself was too faint or too distant to be visible4 ,the actual facts are1 of course1 the other way2 the candle might be visible1 when it was impossible to discern the face which it lighted4 ,hence we learn that the ring nebula must shine by some light of its own1 and now we have to consider how it can be possible for such material to be self-luminous4 ,the light of a nebula does not seem to be like flame2 it can1 perhaps1 be better represented by the pretty electrical experiment with ,geissler's tubes4 ,these are glass vessels of various shapes1 and they are all very nearly empty1 as you will understand when ,i tell you the way in which they have been prepared4 ,a little gas was allowed into each tube1 and then almost all the gas was taken out again1 so that only a mere trace was left4 ,i pass a current of electricity through these tubes1 and now you see they are glowing with beautiful colors4 ,the different gases give out lights of different hues1 and the optician has exerted his skill so as to make the effect as beautiful as possible4 ,the electricity1 in passing through these tubes1 heats the gas which they contain1 and makes it glow2 and just as this gas can1 when heated sufficiently1 give out light1 so does the great nebula1 which is a mass of gas poised in space1 become visible in virtue of the heat which it contains4 ,we are not left quite in doubt as to the constitution of these gaseous nebul1 for we can submit their light to the prism in the way ,i explained when we were speaking of the stars4 ,distant though that ring in ,lyra may be1 it is interesting to learn that the ingredients from which it is made are not entirely different from substances we know on our earth4 ,the water in this glass1 and every drop of water1 is formed by the union of two gases1 of which one is hydrogen4 ,this is an extremely light material1 as you see by a little balloon which ascends so prettily when filled with it4 ,hydrogen also burns very readily1 though the flame is almost invisible4 ,when ,i blow a jet of oxygen through the hydrogen1 ,i produce a little flame with a very intense heat4 ,for instance1 ,i hold a steel pen in the flame1 and it glows and sputters1 and falls down in white-hot drops4 ,it is needless to say that1 as a constituent of water1 hydrogen is one of the most important elements on this earth4 ,it is1 therefore1 of interest to learn that hydrogen in some form or other is a constituent of the most distant objects in space that the telescope has revealed4 ,photographing the ,nebul4 ,illustration3 ,,fig4 #h4 ,,the ,,pleiades4 ,of late years we have learned a great deal about nebul1 by the help which photography has given to us4 ,look at this group of stars which constitutes that beautiful little configuration known as the ,pleiades 7,fig4 #h74 ,it looks like a miniature representation of the ,great ,bear2 in fact1 it would be far more appropriate to call the ,pleiades the ,little ,bear than to apply that title to another quite different constellation1 as has unfortunately been done4 ,the ,pleiades form a group containing six or seven stars visible to the ordinary eye1 though persons endowed with exceptionally good vision can usually see a few more4 ,in an opera-glass the ,pleiades becomes a beautiful spectacle1 though in a large telescope the stars appear too far apart to make a really effective cluster4 ,when ,mr4 ,roberts took a photograph of the ,pleiades he placed a highly sensitive plate in his telescope1 and on that plate the ,pleiades engraved their picture with their own light4 ,he left the plate exposed for hours1 and on developing it not only were the stars seen1 but there were also patches of faint light due to the presence of nebul4 ,it could not be said that the objects on the plate were fallacious1 for another photograph was taken1 when the same appearances were reproduced4 ,when we look at that pretty group of stars which has attracted admiration during all time1 we are to think that some of those stars are merely the bright points in a vast nebula1 invisible to our unaided eyes or even to our mighty telescopes1 though capable of recording its trace on the photographic plate4 ,does not this give us a greatly increased notion of the extent of the universe1 when we reflect that by photography we are enabled to see much which the mightiest of telescopes had previously failed to disclose8 ,of all the nebul1 numbering some thousands1 there is but a single one which can be seen without a telescope4 ,it is in the constellation of ,andromeda1 and on a clear dark night can just be seen with the unaided eye as a faint stain of light on the sky4 ,it has happened before now that persons noticing this nebula for the first time have thought they had discovered a comet4 ,i would like you to try and find out this object for yourselves4 ,if you look at it with an opera-glass it appears to be distinctly elongated4 ,you can see more of its structure when you view it in larger instruments1 but its nature was never made clear until some beautiful photographs were taken by ,mr4 ,roberts 7,fig4 #i74 ,unfortunately1 the nebula in ,andromeda has not been placed in the best position for its portrait from our point of view4 ,it seems as if it were a rather flat-shaped object1 turned nearly edgewise towards us4 ,to look at the pattern on a plate1 you would naturally hold the plate so as to be able to look at it squarely4 ,the pattern would not be seen well if the plate were so tilted that its edge was turned towards you4 ,that seems to be nearly the way in which we are forced to view the nebula in ,andromeda4 ,we can trace in the photograph some divisions extending entirely round the nebula1 showing that it seems to be formed of a series of rings2 and there are some outlying portions which form part of the same system4 ,truly this is a marvellous object4 ,it is impossible for us to form any conception of the true dimensions of this gigantic nebula2 it is so far off that we have never yet been able to determine its distance4 ,indeed1 ,i may take this opportunity of remarking that no astronomer has yet succeeded in ascertaining the distance of any nebula4 ,everything1 however1 points to the conclusion that they are at least as far as the stars4 ,illustration3 ,,fig4 #i4 ,,the ,,great ,,nebula ,,in ,,andromeda4 ,it is almost impossible to apply the methods which we use in finding the distance of a star to the discovery of the distance of the nebul4 ,these flimsy bodies are usually too ill-defined to admit of being measured with the precision and delicacy required for the determination of distance4 ,the measurements necessary for this purpose can only be made from one star-like point to another similar point4 ,if we could choose a star in the nebula and determine its distance1 then of course1 we have the distance of the nebula itself2 but the difficulty is that we have1 in general1 no means of knowing whether the star does actually lie in the object4 ,it may1 for anything we can tell1 lie billions of miles nearer to us1 or billions of miles further off1 and by merely happening to lie in the line of sight1 appear to glimmer in the nebula itself4 ,if we have any assurance that the star is surrounded by a mass of this glowing vapor1 then it may be possible to measure that nebula's distance4 ,it will occasionally happen that grounds can be found for believing that a star which appears to be in the glowing gas does veritably lie therein1 and is not merely seen in the same direction4 ,there are hundreds of stars visible in a good drawing or a good photograph of the famous object in ,andromeda1 and doubtless large numbers of these are merely stars which happen to lie in the same line of sight4 ,the peculiar circumstances attending the history of one star seem1 however1 to warrant us in making the assumption that it was certainly in the nebula4 ,the history of this star is a remarkable one4 ,it suddenly kindled from invisibility into brilliancy4 ,how is a change so rapid in the lustre of a star to be accounted for8 ,in a few days its brightness had undergone an extraordinary increase4 ,of course1 this does not tell us for certain that the star lay in the glowing gas2 but the most rational explanation that ,i have heard offered of this occurrence is that due1 ,i believe1 to my friend ,mr4 ,monck4 ,he has suggested that the sudden outbreak in brilliancy might be accounted for on the same principles as those by which we explain the ignition of meteors in our atmosphere4 ,if a dark star1 moving along with terrific speed through space1 were suddenly to plunge into a dense region of the nebula1 heat and light must be evolved in sufficient abundance to transform the star into a brilliant object4 ,if1 therefore1 we knew the distance of this star at the time it was in ,andromeda1 we should1 of course1 learn the distance of that interesting object4 ,this has been attempted1 and it has thus been proved that the ,great ,nebula must be very much further from us than is that star of whose distance ,i attempted some time ago to give you a notion4 ,we thus realize the enormous size of the ,great ,nebula4 ,it appears that if1 on a map of this object1 we were to lay down1 accurately to scale1 a map of the solar system1 putting the sun in the centre and all the planets around their true proportions out to the boundary traced by ,neptune1 this area1 vast though it is1 would be a mere speck on the drawing of the object4 ,our system would have to be enormously bigger before it sufficed to cover anything like the area of the sky included in one of these great objects4 ,here is a sketch of a nebula1 ,fig4 #aj1 and near ,i have marked a dot1 which is to indicate our solar system4 ,we may feel confident that the ,great ,nebula is at the very least as mighty as this proportion would indicate4 ,illustration3 ,,fig4 #aj4 ,,the ,,solar ,,system ,,as ,,compared ,,with ,a ,,great ,,nebula4 ,,rain ,,and ,,snow 7,,from ,,the ,,forms ,,of ,,water47 ,,by ,,john ,,tyndall4 ,oceanic ,distillation4 ,illustration3 ,,snow ,,crystals4 ,at the equator1 and within certain limits north and south of it1 the sun at certain periods of the year is directly overhead at noon4 ,these limits are called the ,tropics of ,cancer and of ,capricorn4 ,upon the belt comprised between these two circles the sun's rays fall with their mightiest power2 for here they shoot directly downwards1 and heat both earth and sea more than when they strike slantingly4 ,when the vertical sunbeams strike the land they heat it1 and the air in contact with the hot soil becomes heated in turn4 ,but when heated the air expands1 and when it expands it becomes lighter4 ,this lighter air rises1 like wood plunged into water1 through the heavier air overhead4 ,when the sunbeams fall upon the sea the water is warmed1 though not so much as the land4 ,the warmed water expands1 becomes thereby lighter1 and therefore continues to float upon the top4 ,this upper layer of water warms to some extent the air in contact with it1 but it also sends up a quantity of aqueous vapor1 which being far lighter than air1 helps the latter to rise4 ,thus both from the land and from the sea we have ascending currents established by the action of the sun4 ,when they reach a certain elevation in the atmosphere1 these currents divide and flow1 part towards the north and part towards the south2 while from the north and the south a flow of heavier and colder air sets in to supply the place of the ascending warm air4 ,incessant circulation is thus established in the atmosphere4 ,the equatorial air and vapor flow above towards the north and south poles1 while the polar air flows below towards the equator4 ,the two currents of air thus established are called the upper and the lower trade winds4 ,but before the air returns from the poles great changes have occurred4 ,for the air as it quitted the equatorial regions was laden with aqueous vapor1 which could not subsist in the cold polar regions4 ,it is there precipitated1 falling sometimes as rain1 or more commonly as snow4 ,the land near the pole is covered with this snow1 which gives birth to vast glaciers4 ,it is necessary that you should have a perfectly clear view of this process1 for great mistakes have been made regarding the manner in which glaciers are related to the heat of the sun4 ,it was supposed that if the sun's heat were diminished1 greater glaciers than those now existing would be produced4 ,but the lessening of the sun's heat would infallibly diminish the quantity of aqueous vapor1 and thus cut off the glaciers at their source4 ,a brief illustration will complete your knowledge here4 ,in the process of ordinary distillation1 the liquid to be distilled is heated and converted into vapor in one vessel1 and chilled and reconverted into liquid in another4 ,what has just been stated renders it plain that the earth and its atmosphere constitute a vast distilling apparatus in which the equatorial ocean plays the part of the boiler1 and the chill regions of the poles the part of the condenser4 ,in this process of distillation heat plays quite as necessary a part as cold1 and before ,bishop ,heber could speak of ,greenland's icy mountains1 the equatorial ocean had to be warmed by the sun4 ,we shall have more to say upon this question afterwards4 ,the heating of the tropical air by the sun is indirect4 ,the solar beams have scarcely any power to heat the air through which they pass2 but they heat the land and ocean1 and these communicate their heat to the air in contact with them4 ,the air and vapor start upwards charged with the heat thus communicated4 ,tropical ,rains4 ,but long before the air and vapor from the equator reach the poles1 precipitation occurs4 ,wherever a humid warm wind mixes with a cold dry one1 rain falls4 ,indeed the heaviest rains occur at those places where the sun is vertically overhead4 ,we must enquire a little more closely into their origin4 ,fill a bladder about two-thirds full of air at the sea level1 and take it to the summit of ,mount ,blanc4 ,as you ascend1 the bladder becomes more and more distended2 at the top of the mountain it is fully distended1 and has evidently to bear a pressure from within4 ,returning to the sea level you find that the tightness disappears1 the bladder finally appearing as flaccid as at first4 ,the reason is plain4 ,at the sea level the air within the bladder has to bear the pressure of the whole atmosphere1 being thereby squeezed into a comparatively small volume4 ,in ascending the mountain1 you leave more and more of the atmosphere behind2 the pressure becomes less and less1 and by its expansive force the air within the bladder swells as the outside pressure is diminished4 ,at the top of the mountain the expansion is quite sufficient to render the bladder tight1 the pressure within being then actually greater than the pressure without4 ,by means of an air-pump we can show the expansion of a balloon partly filled with air1 when the external pressure has been in part removed4 ,but why do ,i dwell upon this8 ,simply to make plain to you that the unconfined air1 heated at the earth's surface1 and ascending by its lightness1 must expand more and more the higher it rises in the atmosphere4 ,and now ,i have to introduce to you a new fact1 towards the statement of which ,i have been working for some time4 ,it is this3 ,the ascending air is chilled by its expansion4 ,indeed this chilling is one source of the coldness of the higher atmospheric regions4 ,and now fix your eye upon those mixed currents of air and aqueous vapor which rise from the warm tropical ocean4 ,they start with plenty of heat to preserve the vapor as vapor2 but as they rise they come into regions already chilled1 and they are still further chilled by their own expansion4 ,the consequence might be foreseen4 ,the load of vapor is in great part precipitated1 dense clouds are formed1 their particles coalesce to rain-drops1 which descend daily in gushes so profuse that the word torrential is used to express the copiousness of the rainfall4 ,i could show you this chilling by expansion1 and also the consequent precipitation of clouds4 ,thus long before the air from the equator reaches the poles its vapor is in great part removed from it1 having redescended to the earth as rain4 ,still a good quantity of the vapor is carried forward1 which yields hail1 rain1 and snow in northern and southern lands4 ,mountain ,condensers4 ,to complete our view of the process of atmospheric precipitation we must take into account the action of mountains4 ,imagine a south-west wind blowing across the ,atlantic towards ,ireland4 ,in its passage it charges itself with aqueous vapor4 ,in the south of ,ireland it encounters the mountains of ,kerry3 the highest of these is ,magillicuddy's ,reeks1 near ,killarney4 ,now the lowest stratum of this ,atlantic wind is that which is most fully charged with vapor4 ,when it encounters the base of the ,kerry ,mountains it is tilted up and flows bodily over them4 ,its load of vapor is therefore carried to a height1 it expands on reaching the height1 it is chilled in consequence of the expansion1 and comes down in copious showers of rain4 ,from this1 in fact1 arises the luxuriant vegetation of ,killarney2 to this1 indeed1 the lakes owe their water supply4 ,the cold crests of the mountains also aid in the work of condensation4 ,note the consequence4 ,there is a town called ,cahirciveen to the south-west of ,magillicuddy's ,reeks1 at which observations of the rainfall have been made1 and a good distance farther to the north-east1 right in the course of the south-west wind there is another town1 called ,portarlington1 at which observations of rainfall have also been made4 ,but before the wind reaches the latter station it has passed over the mountains of ,kerry and left a great portion of its moisture behind it4 ,what is the result8 ,at ,cahirciveen1 as shown by ,dr4 ,lloyd1 the rainfall amounts to fifty-nine inches in a year1 while at ,portarlington it is only twenty-one inches4 ,again1 you may sometimes descend from the ,alps when the fall of rain and snow is heavy and incessant1 into ,italy1 and find the sky over the plains of ,lombardy blue and cloudless1 the wind at the same time blowing over the plain towards the ,alps4 ,below the wind is hot enough to keep its vapor in a perfectly transparent state2 but it meets the mountains1 is tilted up1 expanded1 and chilled4 ,the cold of the higher summits also helps the chill4 ,the consequence is that the vapor is precipitated as rain or snow1 thus producing bad weather upon the heights1 while the plains below1 flooded with the same air1 enjoy the aspect of the unclouded summer sun4 ,clouds blowing from the ,alps are also sometimes dissolved over the plains of ,lombardy4 ,in connection with the formation of clouds by mountains1 one particularly instructive effect may be here noticed4 ,you frequently see a streamer of cloud many hundred yards in length drawn out from an ,alpine peak4 ,its steadiness appears perfect1 though a strong wind may be blowing at the same time over the mountain head4 ,why is the cloud not blown away8 ,it is blown away2 its permanence is only apparent4 ,at one end it is incessantly dissolved2 at the other end it is incessantly renewed3 supply and consumption being thus equalized1 the cloud appears as changeless as the mountain to which it seems to cling4 ,when the red sun of the evening shines upon these cloud-streamers they resemble vast torches with their flames blown through the air4 ,architecture of ,snow4 ,we now resemble persons who have climbed a difficult peak1 and thereby earned the enjoyment of a wide prospect4 ,having made ourselves masters of the conditions necessary to the production of mountain snow1 we are able to take a comprehensive and intelligent view of the phenomena of glaciers4 ,illustration3 ,,snow ,,crystals4 ,a few words are still necessary as to the formation of snow4 ,the molecules and atoms of all substances1 when allowed free play1 build themselves into definite and1 for the most part1 beautiful forms called crystals4 ,iron1 copper1 gold1 silver1 lead1 sulphur1 when melted and permitted to cool gradually1 all show this crystallizing power4 ,the metal bismuth shows it in a particularly striking manner1 and when properly fused and solidified1 self-built crystals of great size and beauty are formed of this metal4 ,illustration3 ,,snow-,,star4 ,illustration3 ,,snow-,,star4 ,if you dissolve salt-petre in water1 and allow the solution to evaporate slowly1 you may obtain large crystals1 for no portion of the salt is converted into vapor4 ,the water of our atmosphere is fresh though it is derived from the salt sea4 ,sugar dissolved in water1 and permitted to evaporate1 yields crystals of sugar-candy4 ,alum readily crystallizes in the same way4 ,flints dissolved1 as they sometimes are in nature1 and permitted to crystallize1 yield the prisms and pyramids of rock crystal4 ,chalk dissolved and crystallized yields ,iceland spar4 ,the diamond is crystallized carbon4 ,all our precious stones1 the ruby1 sapphire1 beryl1 topaz1 emerald1 are all examples of this crystallizing power4 ,illustration3 ,,snow-,,star4 ,you have heard of the force of gravitation1 and you know that it consists of an attraction of every particle of matter for every other particle4 ,you know that planets and moons are held in their orbits by this attraction4 ,but gravitation is a very simple affair compared to the force1 or rather forces1 of crystallization4 ,for here the ultimate particles of matter1 inconceivably small as they are1 show themselves possessed of attractive and repellent poles1 by the mutual action of which the shape and structure of the crystal are determined4 ,in the solid condition the attracting poles are rigidly locked together2 but if sufficient heat be applied the bond of union is dissolved1 and in the state of fusion the poles are pushed so far asunder as to be practically out of each other's range4 ,the natural tendency of the molecules to build themselves together is thus neutralized4 ,this is the case with water1 which as a liquid is to all appearance formless4 ,when sufficiently cooled the molecules are brought within the play of the crystallizing force1 and they then arrange themselves in forms of indescribable beauty4 ,when snow is produced in calm air1 the icy particles build themselves into beautiful stellar shapes1 each star possessing six rays4 ,there is no deviation from this type1 though in other respects the appearances of the snow-stars are infinitely various4 ,in the polar regions these exquisite forms were observed by ,dr4 ,scoresby1 who gave numerous drawings of them4 ,i have observed them in mid-winter filling the air1 and loading the slopes of the ,alps4 ,but in ,england they are also to be seen1 and no words of mine could convey so vivid an impression of their beauty as the annexed drawings of a few of them1 executed at ,greenwich by ,mr4 ,glaisher4 ,illustration3 ,,snow-,,star4 ,it is worth pausing to think what wonderful work is going on in the atmosphere during the formation and descent of every snow-shower2 what building power is brought into play6 and how imperfect seem the productions of human minds and hands when compared with those formed by the blind forces of nature6 ,but who ventures to call the forces of nature blind8 ,in reality1 when we speak thus we are describing our own condition4 ,the blindness is ours2 and what we really ought to say1 and to confess1 is that our powers are absolutely unable to comprehend either the origin or the end of the operations of nature4 ,but while we thus acknowledge our limits1 there is also reason for wonder at the extent to which science has mastered the system of nature4 ,from age to age1 and from generation to generation1 fact has been added to fact1 and law to law1 the true method and order of the ,universe being thereby more and more revealed4 ,in doing this science has encountered and overthrown various forms of superstition and deceit1 of credulity and imposture4 ,but the world continually produces weak persons and wicked persons2 and as long as they continue to exist side by side1 as they do in this our day1 very debasing beliefs will also continue to infest the world4 ,atomic ,poles4 ,what did ,i mean when1 a few moments ago ,i spoke of attracting and repellent poles8 ,let me try to answer this question4 ,you know that astronomers and geographers speak of the earth's poles1 and you have also heard of magnetic poles1 the poles of a magnet being the points at which the attraction and repulsion of the magnet are as it were concentrated4 ,every magnet possesses two such poles2 and if iron filings be scattered over a magnet1 each particle becomes also endowed with two poles4 ,suppose such particles devoid of weight and floating in our atmosphere1 what must occur when they come near each other8 ,manifestly the repellent poles will retreat from each other1 while the attractive poles will approach and finally lock themselves together4 ,and supposing the particles1 instead of a single pair1 to possess several pairs of poles arranged at definite points over their surfaces2 you can then picture them1 in obedience to their mutual attractions and repulsions1 building themselves together to form masses of definite shape and structure4 ,imagine the molecules of water in calm cold air to be gifted with poles of this description1 which compel the particles to lay themselves together in a definite order1 and you have before your mind's eye the unseen architecture which finally produces the visible and beautiful crystals of the snow4 ,thus our first notions and conceptions of poles are obtained from the sight of our eyes in looking at the effects of magnetism2 and we then transfer these notions and conceptions to particles which no eye has ever seen4 ,the power by which we thus picture to ourselves effects beyond the range of the senses is what philosophers call the ,imagination1 and in the effort of the mind to seize upon the unseen architecture of crystals1 we have an example of the scientific use of this faculty4 ,without imagination we might have critical power1 but not creative power in science4 ,architecture of ,lake ,ice4 ,we have thus made ourselves acquainted with the beautiful snow-flowers self-constructed by the molecules of water in calm1 cold air4 ,do the molecules show this architectural power when ordinary water is frozen8 ,what1 for example1 is the structure of the ice over which we skate in winter8 ,quite as wonderful as the flowers of the snow4 ,the observation is rare1 if not new1 but ,i have seen in water slowly freezing six-rayed ice-stars formed1 and floating free on the surface4 ,a six-rayed star1 moreover1 is typical of the construction of all our lake ice4 ,it is built up of such forms wonderfully interlaced4 ,take a slab of lake ice and place it in the path of a concentrated sunbeam4 ,watch the track of the beam through the ice4 ,part of the beam is stopped1 part of it goes through2 the former produces internal liquefaction1 the latter has no effect whatever upon the ice4 ,but the liquefaction is not uniformly diffused4 ,from separate spots of the ice little shining points are seen to sparkle forth4 ,every one of those points is surrounded by a beautiful liquid flower with six petals4 ,ice and water are so optically alike that unless the light fall properly upon these flowers you cannot see them4 ,but what is the central spot8 ,a vacuum4 ,ice swims on water because1 bulk for bulk1 it is lighter than water2 so that when ice is melted it shrinks in size4 ,can the liquid flowers then occupy the whole space of the ice melted8 ,plainly no4 ,a little empty space is formed with the flowers1 and this space1 or rather its surface1 shines in the sun with the lustre of burnished silver4 ,in all cases the flowers are formed parallel to the surface of freezing4 ,they are formed when the sun shines upon the ice of every lake2 sometimes in myriads1 and so small as to require a magnifying glass to see them4 ,they are always attainable1 but their beauty is often marred by internal defects of the ice4 ,every one portion of the same piece of ice may show them exquisitely1 while a second portion shows them imperfectly4 ,annexed is a very imperfect sketch of these beautiful figures4 ,here we have a reversal of the process of crystallization4 ,the searching solar beam is delicate enough to take the molecules down without deranging the order of their architecture4 ,try the experiment for yourself with a pocket-lens on a sunny day4 ,you will not find the flowers confused2 they all lie parallel to the surface of freezing4 ,in this exquisite way every bit of the ice over which our skaters glide in winter is put together4 ,i said that a portion of the sunbeam was stopped by the ice and liquefied it4 ,what is this portion8 ,the dark heat of the sun4 ,the great body of the light waves and even a portion of the dark ones1 pass through the ice without losing any of their heating power4 ,when properly concentrated on combustible bodies1 even after having passed through the ice1 their burning power becomes manifest4 ,illustration3 ,,liquid ,,flowers ,,in ,,lake ,,ice4 ,and the ice itself may be employed to concentrate them4 ,with an ice-lens in the polar regions ,dr4 ,scoresby has often concentrated the sun's rays so as to make them burn wood1 fire gunpowder1 and melt lead2 thus proving that the heating power is retained by the rays1 even after they have passed through so cold a substance4 ,by rendering the rays of the electric lamp parallel1 and then sending them through a lens of ice1 we obtain all the effects which ,dr4 ,scoresby obtained with the rays of the sun4 ,illustration ,,the ,,organic ,,world 7,,from ,,the ,,elements ,,of ,,science47 ,,by ,,st4 ,,george ,,mivart ,f4,r4,s4 ,the number of all the various kinds of living creatures is so enormous that it would be impossible to study them profitably1 were they not classified in an orderly manner4 ,therefore the whole mass has been divided1 in the first place1 into two supreme groups1 fancifully termed kingdoms--the animal kingdom and the vegetal kingdom4 ,each of these is subdivided into an orderly series of subordinate groups1 successively contained one within the other1 and named sub-kingdoms1 classes1 orders1 families1 genera and species4 ,the lowest group but one is the genus1 which contains one or more different kinds termed species1 as e4g41 the species wood anemone and the species blue titmouse4 ,the lowest group of all--a species--may be said to consist of individuals which differ from each other only by trifling characters1 such as characters due to difference of sex1 while their peculiar organization is faithfully reproduced by generation as a whole1 though small individual differences exist in all cases4 ,the vegetal1 or vegetable1 kingdom1 consists of the great mass of flowering plants1 many of which1 however1 have such inconspicuous flowers that they are mistakenly regarded as flowerless1 as is often the case with the grasses1 the pines1 and the yews4 ,another mass1 or sub-kingdom1 of plants consists of the really flowerless plants1 such as the ferns1 horsetails 7,fig4 #a71 lycopods1 and mosses4 ,sea and fresh-water weeds 7alg71 and mushrooms1 or moulds1 of all kinds 7fungi71 amongst which are the now famous bacteria1 constitute a third and lowest set of plants4 ,illustration3 ,,fig4 #a4 ,,horse-,,tail 7,equisetum drummondii74 ,the animal kingdom consists1 first1 of a sub-kingdom of animals which possess a spinal column1 or backbone1 and which are known as vertebrate animals4 ,such are all beasts1 birds1 reptiles1 and fishes4 ,there are also a variety of remotely allied marine organisms known as tunicates1 sea-squirts1 or ascidians 7,fig4 #b74 ,there is1 further1 an immense group of arthropods1 consisting of all insects1 crab-like creatures1 hundred-legs and their allies1 with spiders1 scorpions1 tics and mites4 ,we have also the sub-kingdom of shell-fish or molluscs1 including cuttle-fishes1 snails1 whelks1 limpets1 the oyster1 and a multitude of allied forms4 ,a multitudinous sub-kingdom of worms also exists1 as well as another of star-fishes and their congeners4 ,there is yet another of zoophytes1 or polyps1 and another of sponges1 and1 finally1 we have a sub-kingdom of minute creatures1 or animalcul1 of very varied forms1 which may make up the sub-kingdom of ,protozoa1 consisting of animals which are mostly unicellular4 ,illustration3 ,,fig4 #b4 ,a ,,tunicate 7,ascidia74 ,multitudinous and varied as are the creatures which compose this immense organic world1 they nevertheless exhibit a very remarkable uniformity of composition in their essential structure4 ,every living creature from a man to a mushroom1 or even to the smallest animalcule or unicellular plant is always partly fluid1 but never entirely so4 ,every living creature also consists in part 7and that part is the most active living part7 of a soft1 viscid1 transparent1 colorless substance1 termed protoplasm1 which can be resolved into the four elements1 oxygen1 hydrogen1 nitrogen and carbon4 ,besides these four elements1 living organisms commonly contain sulphur1 phosphorus1 chlorine1 potassium1 sodium1 calcium1 magnesium and iron4 ,in the fact that living creatures always consist of the four elements1 oxygen1 hydrogen1 nitrogen and carbon1 we have a fundamental character whereby the organic and inorganic 7or non-living7 worlds are to be distinguished1 for as we have seen1 inorganic bodies1 instead of being thus uniformly constituted1 may consist of the most diverse elements and sometimes of but two or even of only one4 ,again1 many minerals1 such as crystals1 are bounded by plain surfaces1 and1 with very few exceptions 7spathic and hematite iron and dolomite are such exceptions7 none are bounded by curved lines and surfaces1 while living organisms are bounded by such lines and surfaces4 ,yet1 again1 if a crystal be cut through1 its internal structure will be seen to be similar throughout4 ,but if the body of any living creature be divided1 it will1 at the very least1 be seen to consist of a variety of minute distinct particles1 called granules1 variously distributed throughout its interior4 ,all organisms consist either--as do the simplest1 mostly microscopic1 plants and animals--of a single minute mass of protoplasm1 or of a few1 or of many1 or of an enormous aggregation of such before-mentioned particles1 each of which is one of those bodies named a cell 7,fig4 #c74 ,cells may1 or may not1 be enclosed in an investing coat or cell-wall4 ,every cell generally contains within it a denser1 normally spheroidal1 body known as the nucleus4 ,now protoplasm is a very unstable substance--as we have seen many substances are whereof nitrogen is a component part--and it possesses active properties which are not present in the non-living1 or inorganic world4 ,in the latter1 differences of temperature will produce motion in the shape of currents1 as we have seen with respect to masses of air and water4 ,but in a portion of protoplasm1 an internal circulation of currents in definite lines will establish itself from other causes4 ,inorganic bodies1 as we have seen1 will expand with heat1 as they may also do from imbibing moisture2 but living protoplasm has an apparently spontaneous power of contraction and expansion under certain external conditions which do not occasion such movements in inorganic matter4 ,illustration3 ,,fig4 #c4 ,,cell ,,from ,a ,,salamander4 n1 nucleus2 n'1 nucleolus embedded in the network of chromatin threads2 k1 network of the cell external to the nucleus2 a1 attraction-sphere or archoplasm containing minute bodies called centrosomes2 cl1 membrane enclosing the cell externally1 nl1 membrane surrounding the nucleus2 c1 centrosomes4 ,under favoring conditions1 protoplasm has a power of performing chemical changes1 which result in producing heat far more gently and continuously than it is produced by the combustion of inorganic bodies4 ,thus it is that the heat is produced which makes its presence evident to us in what we call warm-blooded animals1 the most warm-blooded of all being birds4 ,protoplasm has also the wonderful power of transforming certain adjacent substances into material like itself--into its own substance--and so1 in a sense1 creating a new material4 ,thus it is that organisms have the power to nourish themselves and grow4 ,an animal would vainly swallow the most nourishing food if the ultimate1 protoplasmic particles of its body had not this power of transforming suitable substances brought near them in ways to be hereinafter noticed4 ,without that1 no organism could ever grow4 ,the growth of organisms is utterly different from the increase in size of inorganic bodies4 ,crystals1 as we have seen1 grow merely by external increment2 but organisms grow by an increment which takes place in the very innermost substance of the tissues which compose their bodies1 and the innermost substance of the cells which compose such tissues2 this peculiar form of growth is termed intussusception4 ,protoplasm1 after thus augmenting its mass1 has a further power of spontaneous division1 whereby the mass of the entire organism whereof such protoplasm forms a part1 is augmented and so growth is brought about4 ,the small particles of protoplasm which constitute cells are far indeed from being structureless4 ,besides the nucleus already mentioned there is a delicate network of threads of a substance called chromatin within it1 and another network permeating the fluid of the cell substance1 which invest the nucleus often with further complications4 ,these networks generally perform 7or undergo7 a most complex series of changes every time a cell spontaneously divides4 ,in certain cases1 however1 it appears that the nucleus divides into two in a more simple fashion1 the rest of the cell contents subsequently dividing--each half enclosing one part of the previously divided nucleus4 ,it is by a continued process of cell division that the complex structures of the most complex organisms is brought about4 ,the division of a cell1 or particle of protoplasm1 is indeed a necessary consequence of its complete nutrition4 ,for new material can only be absorbed by its surface4 ,but as the cell grows1 the proportion borne by its surface to its mass1 continually decreases2 therefore this surface must soon be too small to take in nourishment enough1 and the particle1 or cell1 must therefore either die or divide4 ,by dividing1 its parts can continue the nutritive process till their surface1 in turn1 becomes insufficient1 when they must divide again1 and so on4 ,thus the term feeding has two senses4 ,to feed a horse1 ordinarily means to give it a certain quantity of hay1 oats or what not2 and such indeed is one kind of feeding4 ,but obviously1 if the nourishment so taken could not get from the stomach and intestines into the ultimate particles and cells of the horse's body1 the horse could not be nourished1 and still less could it grow4 ,it is this latter process1 called assimilation1 which is the real and essential process of feeding1 to which the process ordinarily so called is but introductory4 ,protoplasm has also the power of forming and ejecting from its own substance1 other substances which it has made1 but which are of a different nature to its own4 ,this function1 as before said1 is termed secretion2 and we know the liver secretes bile1 and that the cow's udder secretes milk4 ,here again we have an external and an internal process4 ,the milk is drawn forth from a receptacle1 the udder1 into which it finds its way1 and so1 in a superficial sense1 it may be called an organ of secretion4 ,nevertheless the true internal secretion takes place in the innermost substance of the cells or particles of protoplasm1 of the milk-land1 which particles really form that liquid4 ,but every living creature consists at first entirely of a particle of protoplasm4 ,therefore every other kind of substance which may be found in every kind of plant or animal1 must have been formed through it1 and be1 in fact1 a secretion from protoplasm4 ,such is the rosy cheek of an apple1 or of a maiden1 the luscious juice of the peach1 the produce of the castor-oil plant1 the baleen that lines the whale's enormous jaws1 as well as that softest product1 the fur of the chinchilla4 ,indeed1 every particle of protoplasm requires1 in order that it may live1 a continuous process of exchange4 ,it needs to be continuously first built up by food1 and then broken down by discharging what is no longer needful for its healthy existence4 ,thus the life of every organism is a life of almost incessant change1 not only in its being as a whole1 but in that of all its protoplasmic particles also4 ,illustration3 ,,fig4 #d4 ,,amoeba ,,shown ,,in ,,two ,,of ,,the ,,many ,,irregular ,,shapes ,,it ,,assumes4 7,after ,howes47 ,the clear space within it is a contractile vesicle4 ,the dark body is the nucleus4 ,in the right-hand figure there is shown a particle of food1 passing through the external surface4 ,prominent among such processes is that of an interchange of gases between the living being and its environment4 ,this process consists in an absorption of oxygen and a giving-out of carbonic acid1 which exchange is termed respiration4 ,lastly1 protoplasm has a power of motion when appropriately acted on4 ,it will then contract or expand its shape by alternate protrusions and retractions of parts of its substance4 ,these movements are termed amoebiform1 because they quite resemble the movements of a small animalcule which is named amoeba4 7,see ,fig4 #d47 ,such is the ultimate structure1 and such are the fundamental activities or functions of living organisms1 as far as they can here be described1 from the lowest animalcule and unicellular plant1 up to the most complex organisms and the body of man himself4 ,illustration ,,inhabitants ,,of ,,my ,,pool 7,,from ,,magic ,,glasses47 ,,by ,,arabella ,b4 ,,buckley4 ,the pool lies in a deep hollow among a group of rocks and boulders1 close to the entrance of the cove1 which can only be entered at low water2 it does not measure more than two feet across1 so that you can step over it1 if you take care not to slip on the masses of green and brown seaweed growing over the rocks on its sides1 as ,i have done many a time when collecting specimens for our salt-water aquarium4 ,i find now the only way is to lie flat down on the rock1 so that my hands and eyes are free to observe and handle1 and then1 bringing my eye down to the edge of the pool1 to lift the seaweeds and let the sunlight enter into the chinks and crannies4 ,in this way ,i can catch sight of many a small being either on the seaweed or the rocky ledges1 and even creatures transparent as glass become visible by the thin outline gleaming in the sunlight4 ,then ,i pluck a piece of seaweed1 or chip off a fragment of rock with a sharp-edged collecting knife1 bringing away the specimen uninjured upon it1 and place it carefully in its own separate bottle to be carried home alive and well4 ,now though this little pool and ,i are old friends1 ,i find new treasures in it almost every time ,i go1 for it is almost as full of living things as the heavens are of stars1 and the tide as it comes and goes brings many a mother there to find a safe home for her little ones1 and many a waif and stray to seek shelter from the troublous life of the open ocean4 ,you will perhaps find it difficult to believe that in this rock-bound basin there can be millions of living creatures hidden away among the fine feathery weeds2 yet so it is4 ,not that they are always the same4 ,at one time it may be the home of myriads of infant crabs1 not an eighth of an inch long1 another of baby sea-urchins only visible to the naked eye as minute spots in the water1 at another of young jelly-fish growing on their tiny stalks1 and splitting off one by one as transparent bells to float away with the rising tide4 ,or it may be that the whelk has chosen this quiet nook to deposit her leathery eggs2 or young barnacles1 periwinkles1 and limpets are growing up among the green and brown tangles1 while the far-sailing velella and the stay-at-home sea-squirts1 together with a variety of other sea-animals1 find a nursery and shelter in their youth in this quiet harbor of rest4 ,and besides these casual visitors there are numberless creatures which have lived and multiplied there1 ever since ,i first visited the pool4 ,tender red1 olive-colored1 and green seaweeds1 stony corallines1 and acorn-barnacles lining the floor1 sea-anemones clinging to the sides1 sponges tiny and many-colored hiding under the ledges1 and limpets and mussels wedged in the cracks4 ,these can be easily seen with the naked eye1 but they are not the most numerous inhabitants2 for these we must search with a magnifying glass1 which will reveal to us wonderful fairy-forms1 delicate crystal vases with tiny creatures in them whose transparent lashes make whirlpools in the water1 living crystal bells so tiny that whole branches of them look only like a fringe of hair1 jelly globes rising and falling in the water1 patches of living jelly clinging to the rocky sides of the pool1 and a hundred other forms1 some so minute that you must examine the fine sand in which they lie under a powerful microscope before you can even guess that they are there4 ,illustration3 ,,fig4 #a4 ,,group ,,of ,,seaweeds4 7,natural size47 #a1 ,ulva ,linza4 #b1 ,sphacelaria filicina4 #c1 ,polysiphonia urceolata4 #d1 ,corallina officinalis4 ,so it has proved a rich hunting-ground1 where summer and winter1 spring and autumn1 ,i find some form to put under my magic glass4 ,there ,i can watch it for weeks growing and multiplying under my care2 moved only from the aquarium1 where ,i keep it supplied with healthy sea-water1 to the tiny transparent trough in which ,i place it for a few hours to see the changes it has undergone4 ,i could tell you endless tales of transformations in these tiny lives1 but ,i want to-day to show you a few of my friends1 most of which ,i brought yesterday fresh from the pool1 and have prepared for you to examine4 ,illustration3 ,,fig4 #b4 ,ulva lactuca1 ,a ,,green-,,seaweed1 ,,greatly ,,magnified ,,to ,,show ,,structure4 7,after ,orested74 s1 ,spores in the cells1 ss1 ,spores swimming out4 h1 ,holes through which spores have escaped4 ,let us begin with seaweeds4 ,i have said that there are three leading colors in my pool--green1 olive1 and red--and these tints mark roughly three kinds of weed1 though they occur in an endless variety of shapes4 ,here is a piece of the beautiful pale green seaweed1 called the ,laver or ,sea-,lettuce1 ,ulva ,linza 7#a1 ,fig4 #a71a which grows in long ribbons in a sunny nook in the water4 ,i have placed under the first microscope a piece of this weed which is just sending out young seaweeds in the shape of tiny cells1 with lashes very like those we saw coming from the moss-flower1 and ,i have pressed them in the position in which they would naturally leave the plant4 ,you will also see on this side several cells in which these tiny spores are forming1 ready to burst out and swim2 for this green weed is merely a collection of cells1 like the single-celled plants on land4 ,each cell can work as a separate plant2 it feeds1 grows1 and can send out its own young spores4 ,footnote #a3 ,the slice given in ,fig4 #b is from a broader-leaved form1 ,u4 lactuca1 because this species1 being composed of only one layer of cells1 is better seen4 ,ulva ,linza is composed of two layers of cells4 ,this deep olive-green feathery weed 7#b1 ,fig4 #a71 of which a piece is magnified under the next microscope 7#b1 ,fig4 #c71 is very different4 ,it is a higher plant1 and works harder for its living1 using the darker rays of sunlight which penetrate into shady parts of the pool4 ,so it comes to pass that its cells divide the work4 ,those of the feathery threads make the food1 while others1 growing on short stalks on the shafts of the feather1 make and send out the young spores4 ,lastly1 the lovely red threadlike weeds1 such as this ,polysiphonia urceolata 7#c1 ,fig4 #a71 carry actual urns on their stems like those of mosses4 ,in fact1 the history of these urns 7see #c1 ,fig4 #c71 is much the same in the two classes of plants1 only that instead of the urn being pushed up on a thin stalk as in the moss1 it remains on the seaweed close down to the stem1 when it grows out of the plant-egg1 and the tiny plant is shut in till the spores are ready to swim out4 ,illustration3 ,,fig4 #c4 ,,three ,,seaweeds ,,of ,,fig4 #a ,,much ,,magnified ,,to ,,show ,,fruits4 7,harvey47 #b1 ,sphacelaria filicina4 #c1 ,polysiphonia urceolata4 #d1 ,corallina officinalis4 ,the stony corallines 7#d1 ,figs4 #a and #c71 which build so much carbonate of lime into their stems1 are near relations of the red seaweeds4 ,there are plenty of them in my pool4 ,some of them1 of a deep purple color1 grow upright in stiff groups about three or four inches high2 and others1 which form crusts over the stones and weeds1 are a pale rose color2 but both kinds1 when the plant dies1 leaving the stony skeleton 7#a1 ,fig4 #d71 are a pure white1 and used to be mistaken for corals4 ,they belong to the same order of plants as the red weeds1 which all live in shady nooks in the pools1 and are the highest of their race4 ,illustration3 ,,fig4 #d4 ,,coralline ,,and ,,sertularia1 ,,to ,,show ,,likeness ,,between ,,the ,,animal ,,sertularia ,,and ,,the ,,plant ,,coralline4 #a1 ,corallina officinalis4 #b1 ,sertularia filicula4 ,my pool is full of different forms of these four weeds4 ,the green ribbons float on the surface rooted to the sides of the pool1 and1 as the sun shines upon it1 the glittering bubbles rising from them show that they are working up food out of the air in the water1 and giving off oxygen4 ,the brown weeds lie chiefly under the shelves of rocks1 for they can manage with less sunlight1 and use the darker rays which pass by the green weeds2 and last of all1 the red weeds and corallines1 small and delicate in form1 line the bottom of the pool in its darkest nooks4 ,and now if ,i hand round two specimens1--one a coralline1 and the other something you do not yet know1--,i am sure you will say at first sight that they belong to the same family1 and1 in fact1 if you buy at the seaside a group of seaweeds gummed on paper1 you will most likely get both these among them4 ,yet the truth is2 that while the coralline 7#a1 ,fig4 #d7 is a plant1 the other specimen 7#b71 which is called ,sertularia filicula1 is an animal4 ,this special sertularian grows up right in my pool on stones or often on seaweeds1 but ,i have here 7,fig4 #e7 another and much smaller one which lives literally in millions hanging its cups downwards4 ,i find it not only under the narrow ledges of the pool sheltered by the seaweed1 but forming a fringe along all the rocks on each side of the cove near to low-water mark1 and for a long time ,i passed it by thinking it was of no interest4 ,but ,i have long since given up thinking this of anything1 especially in my pool1 for my magic glass has taught me that there is not even a living speck which does not open out into something marvellous and beautiful4 ,so ,i chipped off a small piece of rock and brought the fringe home1 and found1 when ,i hung it up in clear sea-water as ,i have done over this glass trough 7,fig4 #e7 and looked at it through the lens1 that each thread of the dense fringe1 in itself not a quarter of an inch deep1 turns out to be a tiny sertularian with at least twenty mouths4 ,you can see this with your pocket lens even as it hangs here1 and when you have examined it you can by and by take off one thread and put it carefully in the trough4 ,i promise you a sight of the most beautiful little beings which exist in nature4 ,illustration3 ,,fig4 #e4 ,sertularia tenella1 ,,hanging ,,from ,a ,,splint ,,of ,,rock ,,over ,a ,,water ,,trough4 ,,also ,,piece ,,enlarged ,,to ,,show ,,the ,,animal ,,protruding4 ,come and look at it4 ,it is a horny-branched stem with a double row of tiny cups all along each side4 ,out of these cups there appear a row of tiny cups all along each side 7see ,fig4 #e71 ,out of these cups there appear from time to time sixteen minute transparent tentacles as fine as spun glass1 which wave about in the water4 ,if you shake the glass a little1 in an instant each crystal star vanishes into its cup1 to come out again a few minutes later2 so that now here1 now there1 the delicate animal-flowers spread out on each side of the stem1 and the tree is covered with moving beings4 ,these tentacles are feelers1 which lash food into a mouth and stomach in each cup1 where it is digested and passed1 through a hole in the bottom1 along a jelly thread which runs down the stem and joins all the mouths together4 ,in this way the food is distributed all over the tree1 which is1 in fact1 one animal with many feeding-cups4 ,some day ,i will show you one of these cups with the tentacles stretched out and mounted on a slide1 so that you can examine a tentacle with a very strong magnifying power4 ,you will then see that it is dotted over with cells1 in which are coiled fine threads4 ,the animal uses these threads to paralyze the creatures on which it feeds1 for at the base of each thread there is a poison gland4 ,in the larger ,sertularia the whole branched tree is connected by jelly threads1 running through the stem1 and all the thousands of mouths are spread out in the water4 ,one large form called ,sertularia cupressina grows sometimes three feet high and bears as many as a hundred thousand cups1 with living mouths1 on its branches4 ,the next of my minute friends ,i can only show to the class in a diagram1 but you will see it under the fourth microscope by and by4 ,i had great trouble in finding it yesterday1 though ,i know its haunts upon the green weed1 for it is so minute and transparent that even when the weed is in a trough a magnifying-glass will scarcely detect it4 ,and ,i must warn you that if you want to know any of the minute creatures we are studying1 you must visit one place constantly4 ,you may in a casual way find many of them on seaweed1 or in the damp ooze and mud1 but it will be by chance only2 to look for them with any certainty you must take trouble in making their acquaintance4 ,illustration3 ,,fig4 #f4 ,thuricolla folliculata and ,chilomonas amygdalum4 7,saville ,kent47 #a1 ,thuricolla erect4 #b1 ,retracted4 #c1 ,dividing4 #d1 ,chilomonas amygdalum4 hc1 ,horny carapace1 cv1 ,contractile vesicle4 v ,closing valves4 ,turning then to the diagram 7,fig4 #f7 ,i will describe it as ,i hope you will see it under the microscope--a curious1 tiny1 perfectly transparent open-mouthed vase standing upright on the weed1 and having an equally transparent being rising up in it and waving its tiny lashes in the water4 ,this is really all one animal1 the vase hc being the horny covering or carapace of the body1 which last stands up like a tube in the centre4 ,if you watch carefully1 you may even see the minute atoms of food twisting round inside the tube until they are digested1 after they have been swept in at the wide open mouth by the whirling lashes4 ,you will see this more clearly if you put a little rice-flour1 very minutely powdered and colored by carmine1 into the water2 for you can trace these red atoms into some round spaces called vacuoles which are dotted over the body of the animal1 and are really globules of watery fluid in which the food is probably partly digested4 ,you will notice1 however1 one round clear space 7cv7 into which they do not go1 and after a time you will be able to observe that this round spot closes up or contracts very quickly1 and then expands again very slowly4 ,as it expands it fills with a clear fluid1 and naturalists have not yet decided exactly what work it does4 ,it may serve the animal either for breathing1 or as a very simple heart1 making the fluids circulate in the tube4 ,the next interesting point about this little being is the way it retreats into its sheltering vase4 ,even while you are watching1 it is quite likely it may all at once draw itself down to the bottom as in ,no4 #b1 and folding down the valves w of horny teeth which grow on each side1 shut itself in from some fancied danger4 ,another very curious point is that1 besides sending forth young ones1 these creatures multiply by dividing in two 7see ,no4 #c1 ,fig4 #f71 each one closing its own part of the vase into a new home4 ,there are hundreds of these ,infusoria1 as they are called1 in my pond1 some with vases1 some without1 some fixed to weeds and stones1 others swimming about freely4 ,even in the water-trough in which this ,thuricolla stands1 ,i saw several smaller forms1 and the next microscope has a trough filled with the minutest form of all1 called a ,monad4 ,these are so small that two thousand of them could lie side by side in an inch2 that is1 if you could make them lie at all1 for they are the most restless little beings1 darting hither and thither1 scarcely even halting except to turn back4 ,and yet though there are so many of them1 and as far as we know they have no organs of sight1 they never run up against each other1 but glide past more cleverly than any clear-sighted fish4 ,these creatures are mostly to be found among decaying seaweed1 and though they are so tiny1 you can still see distinctly the clear space contracting and expanding within them4 ,illustration3 ,,fig4 #g4 ,,living ,,diatoms4 a1 ,cocconema lanceolatum4 b1 ,bacillaria paradoxa4 c1 ,gomphonema marinum4 d1 ,diatoma hyalina4 ,but if there are so many thousands of mouths to feed1 on the tree-like ,sertulari as well as in all these ,infusoria1 where does the food come from8 ,partly from the numerous atoms of decaying life all around1 and the minute eggs of animals and spores of plants2 but besides these1 the pool is full of minute living plants--small jelly masses with solid coats of flint which are moulded into most lovely shapes4 ,plants formed of jelly and flint6 ,you will think ,i am joking1 but ,i am not4 ,these plants1 called ,diatoms1 which live both in salt and fresh water1 are single cells feeding and growing just like those we took from the water-butt1 only that instead of a soft covering they build up a flinty skeleton4 ,they are so small1 that many of them must be magnified to fifty times their real size before you can even see them distinctly4 ,yet the skeletons of these almost invisible plants are carved and chiselled in the most delicate patterns4 ,i showed you a group of these in our lecture on magic glasses1 and now ,i have brought a few living ones that we may learn to know them4 ,the diagram 7,fig4 #g7 shows the chief forms you will see on the different slides4 ,the first one1 ,sacillaria paradoxa 7b1 ,fig4 #g71 looks like a number of rods clinging one to another in a string1 but each one of these is a single-celled plant with a jelly cell surrounding the flinty skeleton4 ,you will see that they move to and fro over each other in the water4 ,the next two forms1 a and c1 look much more like plants1 for the cells arrange themselves on a jelly stem1 which by and by disappears1 leaving only the separate flint skeletons4 ,the last form1 d1 is something midway between the other forms1 the separate cells hang on to each other and also on to a straight jelly stem4 ,illustration3 ,,fig4 #h4 ,a ,,diatom 7,diatoma vulgare7 ,,growing4 a1 b1 ,flint skeleton inside the jelly-cell4 a1 c and d1 b1 ,two flint skeletons formed by new valves1 c and d1 forming within the first skeleton4 ,another species of ,diatoma 7,fig4 #h7 called ,diatoma vulgare1 is a very simple and common form1 and will help to explain how these plants grow4 ,the two flinty valves a1 b inside the cell are not quite the same size2 the older one a is larger than the younger one b and fits over it like the cover of a pill-box4 ,as the plant grows1 the cell enlarges and forms two more valves1 one c fitting into the cover a1 so as to make a complete box ac1 and a second1 d1 back to back with c1 fitting into the valve b1 and making another complete bd4 ,this goes on very rapidly1 and in this plant each new cell separates as it is formed1 and the free diatoms move about quite actively in the water4 ,if you consider for a moment1 you will see that1 as the new valves always fit into the old ones1 each must be smaller than the last1 and so there comes a time when the valves have become too small to go on increasing4 ,then the plant must begin afresh4 ,so the two halves of the last cell open1 and throwing out their flinty skeletons1 cover themselves with a thin jelly layer1 and form a new cell which grows larger than any of the old ones4 ,these1 which are spore-cells1 then form flinty valves inside1 and the whole thing begins again4 ,now1 though the plants themselves die1 or become the food of minute animals1 the flinty skeletons are not destroyed1 but go on accumulating in the waters of the ponds1 lakes1 rivers1 and seas1 all over the world4 ,untold millions have no doubt crumbled to dust and gone back into the waters1 but untold millions also have survived4 ,the towns of ,berlin in ,europe and of ,richmond in the ,united ,states are actually built upon ground called infusorial earth1 composed almost entirely of valves of these minute diatoms which have accumulated to a thickness of more than eighty feet6 ,those under ,berlin are fresh-water forms1 and must have lived in a lake1 while those of ,richmond belong to salt-water forms4 ,every inch of the ground under those cities represents thousands and thousands of living plants which flourished in ages long gone by1 and were no larger than those you will see presently under the microscope4 ,these are a very few of the microscopic inhabitants of my pond1 but1 as you will confuse them if ,i show you too many1 we will conclude with two rather larger specimens1 and examine them carefully4 ,the first1 called the ,cydippe1 is a lovely1 transparent living ball1 which ,i want to explain to you because it is so wondrously beautiful4 ,the second1 the ,sea-mat or ,flustra1 looks like a crumpled drab-colored seaweed1 but is really composed of many thousands of grottos1 the homes of tiny sea-animals4 ,illustration3 ,,fig4 #i4 ,cydippe ,pileus4 #a1 ,animal with tentacles t1 bearing small tendrils t'4 #b1 ,body of animal enlarged4 m1 ,mouth4 c1 ,digestive cavity4 s1 ,sac into which the tentacles are withdrawn4 p1 ,bands with comb-like plates4 #c1 ,portion of a band enlarged to show the moving plates p4 ,let us take the ,cydippe first 7#a1 ,fig4 #i74 ,i have six here1 each in a separate tumbler1 and could have brought many more1 for when ,i dipped my net in the pool yesterday such numbers were caught in it that ,i believe the retreating tide must just have left a shoal behind4 ,put a tumbler on the desk in front of you1 and if the light falls well upon it you will see a transparent ball about the size of a large pea marked with eight bright bands1 which begin at the lower end of the ball and reach nearly to the top1 dividing the outside into sections like the ribs of a melon4 ,the creature is so perfectly transparent that you can count all the eight bands4 ,at the top of the ball is a slight bulge which is the mouth 7m #b1 ,fig4 #i71 and from it1 inside the ball hangs a long bag or stomach1 which opens below into a cavity1 from which two canals branch out1 one on each side1 and these divide again into four canals which go one into each of the tubes running down the bands4 ,from this cavity the food1 which is digested in the stomach1 is carried by the canals all over the body4 ,the smaller tubes which branch out of these canals cannot be seen clearly without a very strong lens1 and the only other parts you can discern in this transparent ball are two long sacs on each side of the lower end4 ,these are the tentacle sacs1 in which are coiled up the tentacles1 which we shall describe presently4 ,lastly you can notice that the bands outside the globe are broader in the middle than at the ends1 and are striped across by a number of ridges4 ,in moving the tumblers the water has naturally been shaken1 and the creature being alarmed will probably at first remain motionless4 ,but very soon it will begin to play in the water1 rising and falling1 and swimming gracefully from side to side4 ,now you will notice a curious effect1 for the bands will glitter and become tinged with prismatic colors1 till1 as it moves more and more rapidly these colors1 reflected in the jelly1 seem to tinge the whole ball with colors like those on a soap-bubble1 while from the two sacs below come forth two long transparent threads like spun glass4 ,at first these appear to be simple threads1 but as they gradually open out to about four or five inches1 smaller threads uncoil on each side of the line till there are about fifty on each line4 ,these short tendrils are never still for long2 as the main threads wave to and fro1 some of the shorter ones coil up and hang like tiny beads1 then these uncoil and others roll up1 so that these graceful floating lines are never two seconds alike4 ,we do not really know their use4 ,sometimes the creature anchors itself by them1 rising and falling as they stretch out or coil up2 but more often they float idly behind it in the water4 ,at first you would perhaps think that they served to drive the ball through the water1 but this is done by a special apparatus4 ,the cross ridges which we noticed on the bands are really flat comb-like plates 7p1 ,fig4 #i71 of which there are about twenty or thirty on each band2 and these vibrate very rapidly1 so that two hundred or more paddles drive the tiny ball through the water4 ,this is the cause of the prismatic colors2 for iridescent tints are produced by the play of light upon the glittering plates1 as they incessantly change their angle4 ,sometimes they move all at once1 sometimes only a few at a time1 and it is evident the creature controls them at will4 ,this lovely fairy-like globe1 with its long floating tentacles and rainbow tints1 was for a long time classed with the jelly-fish2 but it really is most nearly related to the sea-anemones1 as it has a true central cavity which acts as a stomach1 and many other points in common with the ,actinozoa4 ,we cannot help wondering1 as the little being glides hither and thither1 whether it can see where it is going4 ,it has nerves of a low kind which start from a little dark spot 7ng7 exactly at the south pole of the ball1 and at that point a sense-organ of some kind exists1 but what impression the creature gains from it of the world outside we cannot tell4 ,i am afraid you may think it dull to turn from such a beautiful being as this1 to the gray leaf which looks only like a dead dry seaweed2 yet you will be wrong1 for a more wonderful history attaches to this crumpled dead-looking leaf than to the lovely jelly-globe4 ,illustration3 ,,fig4 #aj4 ,,the ,,sea-,,mat ,,or ,,flustra 7,flustra foliacea74 #a1 ,natural size4 #b1 ,much magnified1 s1 ,slit caused by drawing in of the animal a4 ,first of all ,i will pass round pieces of the dry leaf 7#a1 ,fig4 #aj71 and while you are getting them ,i will tell you where ,i found the living ones4 ,great masses of the ,flustra1 as it is called1 line the bottom and sides of my pool4 ,they grow in tufts1 standing upright on the rock1 and looking exactly like hard gray seaweeds1 while there is nothing to lead you to suspect that they are anything else4 ,yesterday ,i chipped off very carefully a piece of rock with a tuft upon it1 and have kept it since in a glass globe by itself with sea-water1 for the little creatures living in this marine city require a very good supply of healthy water and air4 ,i have called it a marine city1 and now ,i will tell you why4 ,take the piece in your hand and run your finger gently up and down it2 you will glide quite comfortably from the lower to the higher part of the leaf1 but when you come back you will feel your finger catch slightly on a rough surface4 ,your pocket lens will show you why this is1 for if you look through it at the surface of the leaf you will see it is not smooth1 but composed of hundreds of tiny alcoves with arched tops2 and on each side of these tops stand two short blunt spines1 making four in all1 pointing upwards1 so as partly to cover the alcove above4 ,as your finger went up it glided over the spines1 but on coming back it met their points4 ,this is all you can see in the dead specimen2 ,i must show you the rest by diagrams1 and by and by under the microscope4 ,first1 then1 in the living specimen which ,i have here1 those alcoves are not open as in the dead piece1 but covered over with a transparent skin1 in which1 near the top of the alcove just where the curve begins1 is a slit 7s #b1 ,fig4 #aj7 ,unfortunately1 the membrane covering this alcove is too dense for you to distinguish the parts within4 ,presently1 however1 if you are watching a piece of this living leaf in a flat water-cell under the microscope1 you will see the slit slowly open1 and begin to turn as it were inside out1 exactly like the finger of a glove1 which has been pushed in at the tip1 gradually rises up when you put your finger inside it4 ,as this goes on1 a bundle of threads appears1 at first closed like a bud1 but gradually opening out into a crown of tentacles1 each one clothed with hairs4 ,then you will see that the slit was not exactly a slit after all1 but the round edge where the sac was pushed in4 ,ah6 you will say1 you are now showing me a polyp like those on the sertularian tree4 ,not so fast1 my friend2 you have not studied what is still under the covering skin and hidden in the living animal4 ,i have1 however1 prepared a slide with this membrane removed and there you can observe the different parts1 and learn that each one of these alcoves contains a complete animal1 and not merely one among many mouths1 like the polyp on ,sertularia4 ,illustration3 ,,fig4 #aa4 ,,diagram ,,of ,,the ,,animal ,,in ,,the ,,flustra ,,or ,,sea-,,mat4 #a1 ,animal protruding4 #b1 ,animal retracted in the sheath1 sh1 ,covering sheath1 s1 ,slit4 t1 ,tentacles4 m1 ,mouth4 th1 ,throat1 st1 ,stomach4 i1 ,intestine1 r1 ,retractor muscle1 e1 ,egg-forming parts4 g1 ,nerve-ganglion4 ,each of these little beings 7a1 ,fig4 #aj7 living in its alcove has a mouth1 throat1 stomach1 intestine1 muscles1 and nerves starting from the ganglion of nervous matter1 besides all that is necessary for producing eggs and sending forth young ones4 ,you can trace all these under the microscope 7see #b1 ,fig4 #aa7 as the creature lies curiously doubled up in its bed1 with its body bent in a loop2 the intestine i1 out of which the refuse food passes1 coming back close up to the slit4 ,when it is at rest1 the top of the sac in which it lies is pulled in by the retractor muscle r1 and looks1 as ,i have said1 like the finger of a glove with the top pushed in4 ,when it wishes to feed this top is drawn out by muscles running round the sac1 and the tentacles open and wave in the water 7#a1 ,fig4 #aa74 ,look now at the alcoves1 the homes of these animals2 see how tiny they are and how closely they fit together4 ,mr4 ,gosse1 the naturalist1 has reckoned that there are six thousand1 seven hundred and twenty alcoves in a square inch2 then if you turn the leaf over you will see that there is another set1 fixed back to back with these1 on the other side1 making in all1 thirteen thousand1 four hundred and forty alcoves4 ,now a moderate-sized leaf of flustra measures about three square inches1 taking all the rounded lobes into account1 so you will see we get forty thousand1 three hundred and twenty as a rough estimate of the number of beings on this one leaf4 ,but if you look at this tuft ,i have brought1 you will find it is composed of twelve such leaves1 and this after all is a very small part of the mass growing round my pool4 ,was ,i wrong1 then1 when ,i said my miniature ocean contains as many millions of beings as there are stars in the heavens8 ,you will want to know how these leaves grew1 and it is in this way4 ,first a little free swimming animal1 a mere living sac provided with lashes1 settles down and grows into one little horny alcove1 with its live creature inside1 which in time sends off from it three to five buds1 forming alcoves all round the top and sides of the first one1 growing on to it4 ,these again bud out1 and you can thus easily understand that1 in this way1 in time a good-sized leaf is formed4 ,meanwhile the creatures also send forth new swimming cells1 which settle down near to begin new leaves1 and thus a tuft is formed2 and long after the beings in earlier parts of the leaf have died and left their alcoves empty1 those round the margin are still alive and spreading4444 ,if you can trace the spore-cells and urns in the seaweeds1 observe the polyps in the ,sertularia1 and count the number of mouths on a branch of my animal fringe 7,sertularia tenella72 if you make acquaintance with the ,thuricolla in its vase1 and are fortunate enough to see one divide in two2 if you learn to know some of the beautiful forms of diatoms1 and can picture to yourself the life of the tiny inhabitants of the ,flustra2 then you will have used your microscope with some effect1 and be prepared for an expedition to my pool1 where we will go together some day to seek new treasures4 ,illustration ,,notes ,,agassiz1 ,j4,l4,r41 naturalist1 born in ,switzerland1 #ahjg2 died1 ,cambridge1 ,mass41 #ahgc4 ,in #ahdf he came to ,america1 after having gained a high reputation in ,europe1 to deliver a course of lectures in ,boston ,on the ,plan of the ,creation1 and met with such success that he spent the rest of his days there1 declining an invitation to return to his native country and to ,paris4 ,in #ahdh he was elected to the chair of ,natural ,history at ,harvard4 ,in #ahej-ea he went on an expedition to the ,florida ,reefs4 ,in #aheh he founded and organized the ,museum of ,comparative ,zology at ,cambridge--and1 later on1 went on his important voyage to ,brazil4 ,in #ahgb he founded and organized the summer school of ,natural ,history at ,buzzard's ,bay4 ,he wrote ,the ,fishes of ,brazil1 ,a ,study of ,glaciers1 ,natural ,history of the ,fresh ,water ,fishes of ,central ,europe1 ,contributions to the ,natural ,history of the ,united ,states 7unfinished71 and with his wife1 ,a ,journey in ,brazil4 ,,ball1 ,,prof4 ,,sir ,r4,s41 ,english astronomer1 born in ,dublin1 #ahdj4 ,was appointed ,lord ,ross's astronomer in #ahfe4 ,professor of mathematics and mechanics at the ,royal ,irish ,college of ,science in #ahgc1 and is now astronomer royal for ,ireland4 ,he is the author of ,the ,story of the ,heavens1 ,starland1 etc41 and is well known as a successful lecturer on astronomical subjects in this country4 ,,darwin1 ,,charles ,r41 ,english naturalist1 born1 #ahji2 died1 #ahhb4 ,he first formulated what is known as the principle of ,natural ,selection4 ,in #ahca he went in the famous scientific voyage of the ,beagle as naturalist1 and afterwards published an account of it4 ,he was one of the most thorough1 careful1 and painstaking scientific men of this or any age4 ,he is the author of many famous books4 ,the ,origin of ,species1 ,the ,descent of ,man1 ,insectivorous ,plants1 ,the ,power of ,movement in ,plants1 ,the ,structure and ,distribution of ,coral ,reefs1 ,geological ,observations on ,volcanic ,islands4 ,the ,formation of ,vegetable ,mould was his last published work4 ,,flammarion1 ,c41 famous ,french astronomer1 born1 #ahdb4 ,he has written many popular works on astronomy1 most of which have been translated into ,english4 ,the ,stars1 ,the ,world ,before the ,creation1 ,uranus1 ,comets1 ,popular ,astronomy1 are among his best known4 ,,holden1 ,,prof4 ,e4,s41 ,american astronomer1 born at ,st4 ,louis1 #ahdf4 ,lieutenant engineers1 ,u4,s4,a41 #ahgj-gc2 professor mathematics1 ,u4,s4,n41 #ahgc-ha2 director ,washburn ,observatory1 #ahha-he2 president ,university of ,california1 #ahhc-hh2 director ,lick ,observatory1 #ahhh-ih4 ,is a member of several learned societies of ,europe4 ,is the author of a ,life of ,william ,herschel1 ,a ,hand-book of the ,lick ,observatory1 ,earth and ,sky1 ,primer of ,heraldry1 ,elementary ,astronomy1 ,family of the ,sun1 ,essays in ,astronomy1 ,stories of the ,great ,astronomers1 etc4 ,,huxley1 ,t4,h41 ,english biologist1 born1 #ahbe2 died1 #ahie4 ,went on an exploring expedition on the ,rattlesnake1 and devoted himself to the study of marine life4 ,for his scientific researches he received many honors4 ,his lectures were models of clearness1 and he could simplify the most difficult subjects4 ,he strongly advocated ,darwin's views and evolutionist doctrines4 ,his writings are numerous and many of them technical4 ,among some of the most popular are ,man's ,place in ,nature1 his ,lay ,sermons1 ,critiques and ,addresses1 ,american ,addresses1 ,physiography1 ,science and ,culture1 ,lessons in ,elementary ,physiology1 etc4 ,,kingsley1 ,c41 ,english clergyman and author1 born1 #ahai2 died1 #ahge4 ,wrote ,westward1 ,ho6 which every boy should read1 ,hypatia1 ,alton ,locke1 ,hereward the ,wake1 etc41 and a charming book of travel1 entitled1 ,at ,last4 ,his ,water ,babies is exceedingly popular1 and his ,heroes is a book much appreciated by the boys and girls alike4 ,,proctor1 ,r4,a41 ,english astronomer1 born1 #ahcd2 died1 #ahhh4 ,he was a very popular writer1 and lectured on astronomical subjects in this country1 and in ,england and her colonies4 ,a memorial teaching observatory is erected in his honor near ,san ,diego1 ,cal4 ,he was a man of untiring industry1 an athlete1 a musician1 and a chess-player4 ,his books are numerous4 ,among them are ,half ,hours with the ,telescope1 ,other ,worlds than ,ours1 ,light ,science for ,leisure ,hours1 ,the ,expanse of ,heaven1 ,the ,moon1 ,the ,borderland of ,science1 ,our ,place ,among ,infinites1 ,myths and ,marvels of ,astronomy1 ,the ,universe of ,suns1 ,other ,suns than ,ours1 etc4 ,,shaler1 ,n4,s41 professor of geology at ,harvard4 ,born ,newport1 ,ky41 #ahda4 ,served in the ,union ,army during the ,civil ,war4 ,instructor zology1 geology1 and paleontology1 ,lawrence ,scientific ,school1 till #ahhg4 ,since then at ,harvard4 ,is the author of ,kentucky a ,pioneer ,commonwealth1 ,the ,story of ,our ,continent1 ,the ,interpretation of ,nature1 ,feature of ,coasts and ,oceans1 ,domesticated ,animals1 ,the ,individual1 ,study of ,life and ,death1 etc4 ,,thompson1 ,,sir ,c4 ,,wyville1 ,english zologist1 born1 #ahcj2 died1 #ahhb4 ,he conducted scientific dredging expeditions in the ,lightning and ,porcupine1 #ahfh-fi1 and was the scientific head of the famous voyage of #fh1ijj miles in the ,challenger for deep-sea explorations 7#ahgb-gf74 ,his books are ,the ,depths of the ,sea1 and ,the ,voyage of the ,challenger4 ,,tyndall1 ,,john1 ,english physicist1 born1 #ahbj4 ,began his original researches in #ahdg1 when teacher of physics in ,queenwood ,college4 ,he and ,professor ,huxley visited the ,alps together1 and they wrote a work on the structure and nature of glaciers4 ,it is impossible to detail the work he has done2 but his inquiries and experiments in connection with light1 heat1 sound1 and electricity have all had practical results4 ,he is a popular lecturer1 and devoted the proceeds of a lecturing tour in this country to founding scholarships at ,harvard and ,columbia ,colleges1 for students devoting themselves to original research4 ,among his books are ,glaciers of the ,alps1 ,mountaineering1 ,heat as a ,mode of ,motion1 ,on ,radiation1 ,hours of ,exercise in the ,alps1 ,fragments of ,science1 ,the ,floating ,matter of the ,air1 and volumes on ,light1 ,sound1 ,electricity1 and the forms of water4 ,,wallace1 ,a4,r41 ,english naturalist and traveller1 born #ahbb2 was educated as land surveyor and architect1 but afterwards devoted himself entirely to ,natural ,history4 ,he explored the ,valley of the ,amazon and ,rio ,negro1 #ahdh-eb1 and travelled in the ,malay ,archipelago and ,papua1 #ahed-fb1 publishing the results of his explorations later on4 ,he also wrote ,contributions to the ,theory of ,natural ,selection1 ,miracles and ,modern ,spiritualism1 ,geographical ,distribution of ,animals1 ,tropical ,nature1 ,island ,life1 etc4 ,,giberne1 ,,agnes1 ,english author--living4 ,began to write at seven years old4 ,her first story for children was published when she was only seventeen4 ,her stories for children have not been so popular as her scientific writings1 ,sun1 ,moon1 and ,stars1 ,the ,starry ,skies1 ,among the ,stars1 ,the ,ocean of ,air1 ,the ,world's ,foundations1 ,radiant ,suns1 etc4 ,,wilson1 ,,andrew1 ,english physiologist and lecturer1 born1 #aheb4 ,is the author of ,studies on ,life and ,sense1 ,leisure ,time ,studies1 ,science ,stories1 ,chapters on ,evolution1 ,wild ,animals1 ,brain and ,nerve1 etc41 and is a constant contributor on scientific subjects to the magazines and newspapers1 contributing weekly ,science ,jottings to the ,illustrated ,london ,news ,,wonders ,,of ,,earth1 ,,sea1 ,,and ,,sky ,,suggestions ,,for ,,supplementary ,,reading ,wonder ,stories of ,science ,d4,n4 ,,beach ,wonders in ,monsterland ,,edward ,w4,d4 ,,cuming ,ocean ,wonders ,w4,e4 ,,damon ,among the ,stars ,,agnes ,,giberne ,the ,scenery of the ,heavens ,,john ,,ellard ,,gorr ,coal and the ,coal ,miners ,,homer ,,greene ,wonders of the ,moon ,a4 ,,guillemin ,the ,sea and ,its ,living ,wonders4 ,g4 ,,hartwig ,the ,wonders of ,plant ,life ,under the ,microscope ,,sophie ,b4 ,,herrick ,marvels of ,animal ,life ,,charles ,f4 ,,holder ,old ,ocean ,,ernest ,,ingersoll ,modern ,seven ,wonders of the ,world ,c4 ,,kent ,madam ,how and ,lady ,why ,,charles ,,kingsley ,wonders of ,optics ,f4 ,,marion ,the ,wonders of ,science ,,henry ,,mayhew ,wonders of ,man and ,nature ,e4 ,,menault ,a ,century of ,electricity ,t4,c4 ,,mendenhall ,the ,orbs of ,heaven ,,ormsby ,s4 ,,mitchell ,under ,foot ,,laura ,d4 ,,nichols ,myths and ,marvels of ,astronomy ,r4,a4 ,,proctor ,the ,wonders of the ,world ,,charles ,g4 ,,rosenberg ,the ,wonders of ,nature ,,professor ,,rudolph ,volcanoes of ,north ,america ,,israel ,,cook ,,russell ,aspects of the ,earth ,n4,s4 ,,shaler ,wonders of the ,bird ,world ,r4,b4 ,,sharpe ,the ,wonders of ,water ,,gaston ,,tissandier ,total ,eclipses of the ,sun ,,mabel ,l4 ,,todd ,wonders of ,insect ,life ,,joseph ,c4 ,,willet