वेदों की प्राचीनता एवं काल-निर्णय / ओरायन (लोकमान्य बाल गंगाधर तिलक - खगोलीय वैदिक शोध)

8 THE ARCTIC HOME IN THE VEDAS. works. The belief, that man is post-glacial and that the Polar regions were never suited for human habitation, still lingers in some quarters, and to those who still hold this view any theory regarding the Polar home of the Aryan race may naturally seem to be a priori impossible. It is better, therefore, to begin with a short statement of the latest scientific conclu- sions on these points. Human races of earlier times have left ample evidence of their existence on the surface of this globe; but like the records of the historic period this evidence does not consist of stately tombs and pyramids, or inscriptions and documents. It is of a humbler kind, and consists of hundreds and thousands of rude or polished instruments of stone and metal recently dug out from old camps, fortifications, burial grounds (tumuli), temples, lake- dwellings, &c. of early times spread over the whole of Europe; and in the hands of the archæologist these have been found to give the same results as the hieroglyphics in the hands of the Egyptologist. These early implements of stone and metals were not previously unknown, but they had not attracted the notice of scientific experts till recently; and the peasants in Asia and Europe, when they found them in their fields, could hardly make any better use of them than that of worshipping the implements so found as htunderbolts or fairy arrows shot down from the sky. But now after a careful study of these remains, archæologists have come to the conclusion that these implements, whose human origin is now undoubtedly established, can be classified into those of Stone (including horn, wood or bone), those of Bronze, and those of Iron, representing three different stages of civilization in the progress of man in prehistoric times. Thus the implements of stone, wood or bone, such as chisels, scrapers, arrow-heads, hatches, daggers, etc., were used when the use of metal was yet unknown, and they were gradually supplanted first by the implements of bronze and then of iron,

PREHISTORIC TIMES. 9 when the ancient man discovered the use of these metals. It is not to be supposed, however, that these three different periods of early human civilization were divided by any hard and fast line of division. They represent only a rough classification, the passage from one period into another being slow and gradual. Thus the implements of stone must have continued to be used for a long time after the use of bronze became known to the ancient man, and the same thing must have occurred as he passed from the Bronze to the Iron age. The age of bronze, which is a compound of copper and tin in a definite proportion, requires an antecedent age of copper; but sufficient evidence is not yet found to prove the separate existence of copper and tin ages, and hence it is considered pro- bable that the art of making bronze was not invented in Europe, but was introduced there from other countries either by com- merce or by the Indo-European race going there from outside.* Another fact which requires to be noted in connection with these ages is that the Stone or the Bronze age in one country was not necessarily synchronous with the same age in another country. Thus we find a high state of civilization in Egypt at about 6000 B. C., when the inhabitants of Europe were in the early stages of the Stone age. Similarly Greece had advanced to the Iron age, while Italy was still in the Bronze period, and the West of Europe in the age of Stone. This shows that the progress of civilization was slow in some and rapid in other places, the rate of progress varying according to the local circumstances of each place. Broadly speaking, however, the three periods of Stone, Bronze and Iron may be taken to represent the three stages of civilization anterior to the historic period. Of these three different ages, the oldest or the Stone age is further divided into the Palæolithic and the Neolithic period, or the old and the new Stone age. The distinction is

• Lubbock's Prehistoric Times, 1890 Ed., pp. 4 and 64.

10 THE ARCTIC HOME IN THE VEDAS. based upon the fact that the stone implements of the Palæoli- thic age are found to be very rudely fashioned, being merely chipped into shape and never ground or polished as is the case with the implements of the new Stone age. Another characteristic of the Palæolithic period is that the implements of the period are found in places which plainly show a much greater antiquity than can be assigned to the remains of the Neolithic age, the relics of the two ages being hardly, if ever, found together. The third distinction between the Palæolithic and the Neolithic age is that the remains of the Palæolithic man are found associated with those of many great mammals, such as the cave bear, the mammoth and wooly- haired rhinoceros, that became either locally or wholly extinct before the appearance of the Neolithic man on the stage. In short, there is a kind of hiatus or break between the Palæolithic and Neolithic man requiring a separate classification and treat- ment for each. It may also be noted that the climatic conditions and the distribution of land and water in the Palæolithic period were different from those in the Neolithic period; while from the beginning of the Neolithic period the modern conditions, both geographical and climatic, have prevailed almost unaltered upto the present time. To understand the relation of these three ages with the geological periods into which the history of the earth is divided we must briefly consider the geological classification. The geologist takes up the history of the earth at the point where the archæo- logist leaves it, and carries it further back into remote antiquity. His classification is based upon an examination of the whole system of stratified rocks, and not on mere relics found in the surface strata. These stratified rocks have been divided into five principal classes according to the character of the fossils found in them, and they represent five different periods in the history of our planet. These geological eras, like the three ages of Stone,

PREHISTORIC TIMES. ii Bronze and Iron, cannot be separated very sharply from each other. But taken as a whole we can clearly distinguish one era from another by its characteristic fossil remains. Each of these geological ages or eras is again subdivided into a number of different periods. The order of these Eras and Periods, begin- ning with the newest, is as follows:— Eras. Periods. Post-Tertiary or Quaternary... { Recent (Post-Glacial). Pleistocene (Glacial). Tertiary or Cainozoic ... ... ... { Pliocene. Miocene. Oligocene. Eocene. Secondary or Mesozoic ... ... { Cretaceous. Jurassic. Triassic. Primary or Palæozoic ... ... { Permian. Carboniferous. Devonian, and Old Red Sandstone. Silurian. Cambrian. Archæan or Eozoic ... ... ... Fundamental Gneiss. Thus the oldest of the stratified rocks at present known is the Archæan or Eozoic. Next in chronological order come the Primary or the Palæozoic, the Secondary or the Mesozoic, the Tertiary or Cainozoic, and last the Quarternary. The Quaternary era, with which alone we are here concerned, is subdivided into the Pleistocene or the Glacial, and the Recent or the Post-Glacial period; the close of the first and the beginning of the second being marked by the last Gla- cial epoch, or the Ice Age, during which the greater portion of northern Europe and America was covered with an ice-cap several thousand feet in thickness. The Iron age, the Bronze age and the Neolithic age come under the Recent or the

12 . THE ARCTIC HOME IN THE VEDAS. Post-Glacial period, while the Palæolithic age is supposed to fall in the Pleistocene period, though some of the palæolithic remains are post-glacial, showing that the palæolithic man must have survived the Ice Age for some time. Latest discoveries and researches enable us to carry the antiquity of man still further by establishing the fact that man existed even in the Tertiary era. But apart from it, there is, now, at any rate, overwhelming evidence to conclusively prove the wide-spread existence of man throughout the Quaternary era, even before the last Glacial period. Various estimates have been made regarding the time of the commencement of the Neolithic age, but the oldest date assigned does not exceed 5000 B. C., a time when flourishing empires existed in Egypt and Chaldea. These estimates are based on the amount of silt which has been found accumulated in some of the smaller lakes in Switzerland since the lake-dwellers of the Neolithic period built their piled villages therein. The peat-mosses of Denmark afford means for another estimate of the early Neolithic period in that country. These mosses are formed in the hollows of the glacial drift into which trees have fallen and become gradually converted into peat in course of time. There are three successive periods of vegetation in these peat-beds, the upper one of beech, the middle one of oak, and the lowest of all, one of fir. These changes in the vegetation are attributed to slow changes in the climate and it is ascertained from implements and remains found in these beds, that the Stone age corresponds mainly with that of Fir and partly with that of Oak, while the Bronze age agrees mainly with the period of Oak, and the Iron with that of Beech. It has been calculated that about 16,000 years will be requ- ired for the formation of these peat-mosses, and according to this estimate we shall have to place the commencement of the Neolithic age in Denmark, at the lowest, not later than 10,000 years ago.

PREHISTORIC TIMES. 13 But these estimates are not better than mere approximations, and generally speaking we may take the Neolithic age in Europe as commencing not later than 5000 B. C. But when we pass from the Neolithic to the Palæolithic period the difficulty of ascertaining the commencement of the latter becomes still greater. In fact we have here to ascertain the time when the Post-Glacial period commenced. The Palæolithic man must have occupied parts of Western Europe shortly after the disappearance of the Ice Age and Prof. Geikie considers that there are reasons for supposing that he was inter- glacial. The Glacial period was characterised by geographical and climatic changes on an extensive scale. These changes and the theories regarding the cause or the causes of the Ice Age will be briefly stated in the next chapter. We are here concerned with the date of the commencement of the Post-Glacial period, and there are two different views entertained by geologists on the subject. European geologists think that as the beginning of the Post-Glacial period was marked with great movements of eleva- tion and depression of land, and as these movements take place very slowly, the commencement of the Post-Glacial period cannot be placed later than 50 or 60 thousand years ago. Many American geologists, on the other hand, are of opinion that the close of the last Glacial period must have taken place at a much more recent date. They draw this inference from the various estimates of time required for the erosion of valleys and accumulation of alluvial deposits since the last Glacial period. Thus according to Gilbert, the post-glacial gore of Niagara at the present rate of erosion must have been excavated within 7000 years ¹. Other American geologists from similar observations at various other places have arrived at the conclusion that not more than about 8000 years have

1. See Geikie's Fragments of Earth Lore, p. 286; also Dr. Bonney's. Story of our Planet, p. 560.

14 . THE ARCTIC HOME IN THE VEDAS. elapsed since the close of the last Glacial period. This estimate agrees very well with the approximate date of the Neolithic period ascertained from the amount of silt in some of the lakes in Switzerland. But it differs materially from the estimate of the European geologists. It is difficult to decide, in the present state of our knowledge, which of these estimates is correct. Probably the Glacial and the Post-Glacial period may not, owing to local causes, have commenced or ended at one and the same time in different places, just as the ages of Stone and Bronze were not synchronous in different countries. Prof. Geikie does not accept the American estimate on the ground that it is inconsistent with the high antiquity of the Egyptian civilisation, as ascertained by recent researches. But if no traces of glaciation are yet found in Africa this objection loses its force, while the arguments by which the American view is supported remain uncontradicted. There are other reasons which go to support the same view. All the evidence regarding the existence of the Glacial period comes form the North of Europe and America; but no traces of glaciation have been yet discovered in the Northern Asia or North Alaska. It is not to be supposed, however, that the northern part of Asia did not enjoy a genial climate in early times. As observed by Prof. Geikie "everywhere throughout this vast region alluvial deposits are found packed up with the remains of mammoth, woolly rhinoceros, bison, and horse;" and "the fossils are usually so well preserved that on one occasion the actual carcass of a mammoth was exposed in so fresh a state that dogs ate the flesh thereof." * These and other equally indisputable facts clearly indicate the existence in Siberia of a mild and genial climate at a time, which, from the freshness of the fossil remains, cannot be supposed to be removed from the present by several *. See Geikie's Great Ice Age, 1st Ed., p. 495; Dr. Croll's Climate and Cosmology, p. 179.

PREHISTORIC TIMES. 15 thousands of years. Again in North Africa and Syria we find in dry regions wide-spread fluviatile accumulations which are believ- ved to be indications of rainy seasons, contemporaneous with the Glacial period of Europe.* If this contemporaneity can be established, the high estimate of time for the commencement of the Post-Glacial period in Europe will have to be given up, or at any rate much curtailed. As regards the races which inhabited Europe in these early ages, the evidence furnished by human remains or skulls shows that they were the direct ancestors of the races now living in the different parts of Europe. The current classification of the human races into Aryan, Semetic, Mongolian, &c. is based upon the linguistic principle; but it is evident that in dealing with ancient races the archæologist and the geologist cannot adopt this princi- ple of division, inasmuch as their evidence consists of relics from which no inference can be drawn as to the language used by the ancient man. The shape and the size of the skull have, therefore, been taken as the chief distinguishing marks to classify the different races of prehistoric times. Thus if the extreme breadth of a skull is three-fourths, or 75 per cent., of its length or lower, it is classed as long-headed or dolicho-cephalic, while if the breadth is higher than 83 per cent. of the length, the skull is said to be brachy-cephalic or broad-headed; the intermediate class being styled ortho-cephalic, or sub-dolicho-cephalic, or sub-brachy- cephalic according as it approaches one or the other of these types. Now from the examination of the different skulls found in the Neolithic beds it has been ascertained that Europe in those early days was inhabited by four different races, and that the existing European types are directly descended from them. Of these four races two were dolicho-cephalic, one tall and one short; and two brachy-cephalic similarly divided. But the Aryan languages are,

• See Geikie's Fragments of Earth Lore, p. 252.

16 'THE ARCTIC HOME IN THE VEDAS. at present, spoken in Europe by races exhibiting the charac- teristics of all these types. It is, however, evident that one alone of these four ancient races can be the real representative of the Aryan race, though there is a strong difference of opinion as to which of them represented the primitive Aryans. German writers, like Posche and Penka, claim that the tall dolicho-cephalic race, the ancestors of the present Germans, were the true representative Aryans; while French writers, like Chavee and M. de Mortillet, maintain that the primitive Aryans were brachy-cephalic and the true Aryan type is represented by the Gauls. Canon Taylor in his 'Origin of the Aryans sums up the controversy by observing that when two races come in contact, the probability is that the speech of the most cultured will prevail, and therefore “it is" he says “an easier hypothesis to suppose that the dolicho- cephalic savages of the Baltic coast acquired Aryan speech from their brachy-cephalic neighbours, the Lithuanians, than to suppose, with Penka, that they succeeded in some remote age in Aryanis- ing the Hindus, the Romans and the Greeks.”* Another method of determining which of these four races represented the primitive Aryans in Europe is to compare the grades of civilisation attained by the undivided Aryans, as ascertained from linguistic palæontology, with those attained by the Neolithic races as disclosed by the remains found in their dwellings. As for the Palæolithic man his social condition appears to have been far below that of the undivided Aryans; and Dr. Schrader considers it as indubitably either non-Indo-European or pre-Indo-European in character. The Palæolithic man used stone hatchets and bone needles, and had attained some proficiency in the art of sculpture and drawing, as exhibited by outlines of various animals carved on bones &c.; but he was clearly unacquainted

• See Taylor's Origin of the Aryans, p. 243.

PREHISTORIC TIMES. . 17 with the potter's art and the use of metals. It is only in the Neolithic period that we meet with pottery in the piled villages of lake-dwellers in Switzerland. But even the oldest lake-dwellers seem to have been unacquainted with the use of metals and waggons, both of which were familiar to the undivided Aryans. No trace of woollen cloth is again found in these lake-dwellings, even when sheep had become numerous in the Bronze age. But with these exceptions the culture of the Swiss lake-dwellings is con- sidered by Dr. Schrader to be practically of the same character as the culture common to the European members of the Indo- Germanic family, and he, therefore, ventures to suggest, though cautiously, that "from this point of view there is nothing to prevent our assuming that the most ancient inhabitants of Switzer- land were a branch of the European division" of the Aryan race.* But though recent discoveries have brought to light these facts about the human races inhabiting Europe in prehistoric times, and though we may, in accordance with them, assume that one of the four early Neolithic races represented the primitive Aryans in Europe, the question whether the latter were autochth- onous, or went there from some other place and then succeeded in Aryanising the European races by their superior culture and civilisation, cannot be regarded as settled by these discoveries. The date assigned to the Neolithic period as represented by Swiss lake-dwellers is not later than 5000 B. C., a time when Asiatic Aryans were probably settled on the Jaxartes; and it is admitted that the primitive Aryans in Europe could not have been the de- scendants of the Palæolithic man. It follows, therefore, that if we discover them in Europe in the early Neolithic times they must have gone there from some other part of the *Dr. Schrader's Prehistoric Antiquities of the Aryan Peoples, translated by Jevons, Part IV. Ch. xi. p. 368.

18 . THE ARCTIC HOME IN THE VEDAS. globe. The only other alternative is to assume that one of the four Neolithic races in Europe developed a civilisation quite independently of their neighbours, an assumption, which is impro- bable on its face. Although, therefore, we may, in the light of recent scientific discoveries, give up the theory of successive migrations into Europe from a common home of the Aryan race in Central Asia in early times, yet the question of the primeval home of the Aryan race, a question with which we are mainly concerned in this book, still remains unsolved. When and where the primitive Aryan tongue was developed is again another difficult question which is not satisfactorily answered. Canon Taylor, after comparing the Aryan and Ural-Altaic languages, hazards a conjecture that at the close of the reindeer, or the last period of the Palæolithic age, a Finnic people appeared in Western Europe, whose speech remaining stationary is represent- ed by the agglutinative Basque, and that much later, at the be- ginning of the pastoral age, when the ox had been tamed, a taller and more powerful Finno-Ugric people developed in Central Europe the inflexive Aryan speech.* But this is merely a conjecture, and it does not answer the question how the Indo- Iranians with their civilisation are found settled in Asia at a time when Europe was in the Neolithic age. The Finnic language again discloses a number of culture words borrowed from the Aryans, and it is unlikely that the language of the latter could have got its inflection from the Finnic language. A mere similarity of inflectional structure is no evidence whatsoever for deciding who borrowed from whom, and it is surprising that the above suggestion should come from scholars, who have assailed the theory of successive Aryan migrations from a common Asiatic home, a theory which, amongst others, was based on linguistic grounds. Why did the Finns twice migrate from their home is also

• The Origin of the Aryans, p. 296.

PREHISTORIC TIMES. 19 left unexplained. For reasons like these it seems to me more probable that the Finns might have borrowed the culture words from the Aryans when they came in contact with them, and that the Aryans were autochthonous neither in Europe nor in Central Asia, but had their original home somewhere near the North Pole in the Palæolithic times, and that they migrated from this place southwards in Asia and Europe, not by any 'irresistible impulse,' but by unwelcome changes in the climatic conditions of their original home. The Avesta preserves traditions which fully support this view. But these have been treated as valueless by scholars, who worked up their theories at a time when man was regarded as post-glacial, and the Avestic traditions were, it was believed, not supported by any Vedic authority. But with the time-telescope of a wider range supplied to us by recent scientific discoveries it has become possible to demonstrate that the Avestic traditions represent a real historical fact and that they are fully supported by the testimony of the Vedas. The North Pole is already considered by several eminent scientific men as the most likely place where plant and animal life first originated; and I believe it can be satisfactorily shown that there is enough positive evidence in the most ancient books of the Aryan race, the Vedas and the Avesta, to prove that the oldest home of the Aryan people was somewhere in regions round about the North Pole. I shall take up this evidence after examining the climatic conditions of the Pleistocene or the Glacial period and the astronomical characteristics of the Arctic regions in the next two chapters,

CHAPTER II. THE GLACIAL PERIOD. Geological climate—Uniform and gentle in early ages—Due to different distribution of land and water—Climatic changes in the Quaternary era—The Glacial epoch—Its existence undoubtedly proved—Extent of glaciation—At least two Glacial periods— Accompanied by elevation and depression of land—Mild and genial Inter-glacial climate even in the Arctic regions—Various theories regarding the cause of the Ice Age stated—Lyell's theory of geographical changes—Showing long duration of the Glacial period—Croll's theory—Effect of the precession of the equinoxes on the duration and intensity of seasons—The cycle of 21,000 years—The effect enhanced by the eccentricity of the earth's orbit—Maximum difference of 33 days between the duration of summer and winter—Sir Robert Ball's calculations regarding the average heat received by each hemisphere in summer and winter—Short and warm summers and long and cold winters, giving rise to a Glacial epoch—Dr. Croll's extraordinary estimate regarding the duration of the Glacial epoch—Based on the maximum value of the eccentricity of the earth's orbit —Questioned by astronomers and geologists—Sir Robert Ball's and Newcomb's view—Croll's estimates inconsistent with geological evidence—Opinions of Prof. Geikie and Mr. Hudleston —Long duration of the Glacial period—Summary of results. THE climate of our globe at the present day is characterised by a succession of seasons, spring, summer, autumn, and winter, caused by the inclination of the earth's axis to the plane of the ecliptic. When the North Pole of the earth is turned away from the sun in its annual course round that luminary, we have winter in the northern and summer in the southern hemisphere, and vice versa when the North Pole is turned towards the sun. The cause of the rotation of seasons in the different hemispheres is thus very simple, and from the permanence of this cause one may be led to think

THE GLACIAL PERIOD. 21 that in the distant geological ages the climate of our planet must have been characterised by similar rotations of hot and cold seasons. But such a supposition is directly contradicted by geological evidence. The inclination of the earth's axis to the plane of the ecliptic, or what is technically called the obliquity of the ecliptic, is not the sole cause of climatic variations on the surface of the globe. High altitude and the existence of oceanic and aerial currents, carrying and diffusing the heat of the equatorial region to the other parts of the globe, have been found to produce different climates in countries having the same latitude. The Gulf Stream is a notable instance of such oceanic currents, and had it not been for this stream the climate in the North-West of Europe would have been quite different from what it is at present. Again, if the masses of land and water be differently distributed from what they are at present, there is every reason to suppose that different climatic conditions will prevail on the surface of the globe from those which we now experience, as such a distribution would materially alter the course of oceanic and aerial currents going from the equator to the Poles. Therefore, in the early geological ages, when the Alps were low and the Himalayas not yet upheaved, and when Asia and Africa were represented only by a group of islands, we need not be surprised if, from geological evidence of fossil fauna and flora, we find that an equable and uniform climate prevailed over the whole surface of the globe as the result of these geographical conditions. In Mesozoic and Cainozoic times this state of things appears to have gradually changed. But though the climate in the Secondary and the Tertiary era was not probably as remarkably uniform as in the Primary, yet there is clear geological evidence to show that until the close of the Pliocene period in the Tertiary era the climate was not yet differentiated into zones and there were then no hot and cold extremes as at present. The close

22 THE ARCTIC HOME IN THE VEDAS. of the Pliocene and the whole of the Pleistocene period was marked by violent changes of climate bringing on what is called the Glacial and Inter-Glacial epochs. But it is now conclusively established that before the advent of this period a luxuriant forest vegetation, which can only grow and exist at present in the tropical or temperate climate, flourished in the high latitude of Spitzbergen, where the sun goes below the horizon from Novem- ber till March, thus showing that a warm climate prevailed in the Arctic regions in those days. It was in the Quaternary or the Pleistocene period that the mild climate of these regions underwent sudden alterations, producing what is called the Glacial period. The limits of this Glacial period may not so exactly coincide with those of the Pleistocene as to enable us to say that they were mathematically co-extensive, but, still, in a rough sense we may take these two periods as coinciding with each other. It is impossible within the limits of a short chapter to give even a summary of the evidence proving the existence of one or more Glacial epochs in the Pleistocene period. We may, however, briefly indicate its nature and see what the geologists and the physicists have to say as regards the causes that brought about such extensive changes of climate in the Quaternary era. The existence of the Glacial period is no longer a matter of doubt, though scientific men are not agreed as to the causes which produced it. Ice-sheets have not totally disappeared from the surface of the earth, and we can still watch the action of ice as glaciers in the valleys of the Alps or in the lands near the Pole, like Greenland which is still covered with a sheet of ice so thick as to make it unfit for the growth of plants or the habitation of animals. Studying the effects of glacial action in these places geologists have discovered abundant traces of similar action of ice in former times over the whole of Northern Europe and America. Rounded and scratched stones, till or boulder-clay, and the

THE GLACIAL PERIOD. 23 rounded appearance of rocks and mountains clearly point out that at one period in the history of our globe northern parts of Europe and America must have been covered for a long time with a sheet of ice several hundreds of feet in thickness. The ice which thus invaded the northern portion of America and Europe did not all radiate from the Pole. The evidence of the direction of the striæ, or scratches engraved on rocks by ice, undoubtedly proves that the ice-caps spread out from all elevated places or mountains in different directions. These ice-sheets of enormous thickness covered the whole of Scandinavia, filled up the North Sea, invaded Britain down to the Thames valley, greater portion of Germany and Russia as far south as Moscow and almost as far east as the Urals. It is calculated that at least a million of square miles in Europe and more in North America were covered by the debris of rocks ground down by these glaciers and ice-caps, and it is from this debris that geologists now infer the existence of an Ice Age in early times. The examina- tion of this debris shows that there are at least two series of boulder clay indicating two periods of glaciation. The debris of the second period has disturbed the first layer in many places, but enough remains to show that there were two distinct beds of boulder-clay and drifts, belonging to two different periods. Prof. Geikie mentions four such Glacial periods, with corresponding Inter-Glacial periods, as having occurred in succession in Europe during the Pleistocene period. But though this opinion is not accepted by other geologists, yet the existence of two Glacial epochs, with an intervening Inter-Glacial period, is now consider- ed as conclusively established. A succession of cold and warm climates must have chara- cterised these Glacial and Inter-Glacial periods, which were also accompanied by extensive movements of depression and elevation of land, the depression taking place after the land was weighed down with the enormous mass of ice. Thus

24 THE ARCTIC HOME IN THE VEDAS. a period of glaciation was marked by elevation, extreme cold and the invasion of the ice-caps over regions of the present Temperate zone; while an inter-glacial period was accompanied by depression of land and milder and congenial climate which made even the Arctic regions habitable. The remains of the Palæolithic man have been found often imbedded between the two boulder-clays of two different Glacial periods, a fact which conclusively estab- lishes the existence of man in the Inter-Glacial period in the Quaternary era. Prof. Geikie speaking of the changes of climate in the Glacial and Inter-Glacial period remarks that "during the Inter-Glacial period the climate was characterised by clement winters and cool summers so that the tropical plants and animals, like elephants, rhinoceroses and hippopotamuses, ranged over the whole of the Arctic region, and in spite of numerous fierce carni- vora, the Palæolithic man had no unpleasant habitation there."* It will thus be seen that in point of climate the Pleistocene period, or the early Quaternary era, was intermediate between the early geological ages when uniform genial climate prevailed over the globe, and the modern period when it is differentiated into zones. It was, so to speak, a transitional period marked by violent changes in the climate, that was mild and genial in the Inter-Glacial, and severe and inclement during the Glacial period. It was at the beginning of the Post-Glacial or the Recent period that modern climatic conditions were established. Prof. Geikie is, however, of opinion that even the beginning of the Post-Glacial period was marked, at least in North-Western Europe, by two alternations of genial and rainy-cold climate before the present climatic condi- tions became established.† But though the fact of the Ice Age and the existence of a milder climate within the Arctic regions in the Inter-Glacial Fragments of Earth Lore, p. 266. † Prehistoric Europe, p. 530.

THE GLACIAL PERIOD. 25 time is indubitably proved, yet scientific men have not been as yet able to trace satisfactorily the causes of this great catastrophe. Such immense mass of ice as covered the whole of Northern Europe and America during this period could not, like anything else, come out of nothing. There must be heat enough in certain parts of the globe to create by evaporation sufficient vapour, and aerial currents are required to transfer it to the colder regions of the globe, there to be precipitated in the form of ice. Any theory regarding the cause of the Ice Age which fails to take this fact into account is not only inadequate but worthless. A succession of Glacial periods, or, at any rate, the occurrence of two Glacial periods, must again be accounted for by the theory that may be proposed to explain these changes; and if we test the different theories advanced in this way, many of them will be at once found to be untenable. It was, for instance, once urged that the Gulf Stream, which, at present, imparts warmth to the countries in the North-West of Europe, might have been turned away from its course in the Pleistocene period by the submergence of the Isthmus of Panama, thus converting the countries on the North-Western coast of Europe into lands covered by ice. There is, however, no geological evidence to show that the Isthmus of Panama was submerged in the Pleistocene period, and we must, therefore, give up this hypothesis. Another theory started to account for the catastrophe was that the earth must have passed through cold and hot regions of space, thus giving rise to Glacial and Inter-Glacial periods respectively. But this too is unsupported by any evidence. A third suggestion advanced was that the supply of solar heat on earth must have varied in such a way as to give rise to warm and cold climates but this was shown to be a mere conjecture. A change in the position of the earth's axis might indeed cause such sudden changes in the climate; but a change in the 4

26 THE ARCTIC HOME IN THE VEDAS. axis means a change in the equator, and as the earth owing to its diurnal rotation causes the equatorial regions to bulge out, a change in the axis would give rise to a second equatorial protu- berance, which, however, is not observable, and the theory cannot, therefore, be accepted. A gradual cooling of the earth would make the Polar regions habitable before the other parts of the globe; but a succession of Glacial epochs cannot be accounted for on this theory. Thus out of the various theories advanced to account for the vicissitudes of climate in the Pleistocene period only two have now remained in the field, the first that of Lyell which explains the changes by assuming different distribution of land and water combined with sudden elevation and submergence of large landed areas, and the second that of Croll which traces the glaciation to the precession of the equinoxes combined with the high value of the eccentricity of the earth's orbit. Lyell's theory has been worked out by Wallace who shows that such geographical changes are by themselves sufficient to produce heat and cold required to bring on the Glacial and Inter-Glacial periods. We have seen that in earlier geological ages a pleasant and equable climate prevailed over the whole surface of the globe owing mainly to different distribution of land and water, and the theory advanced by Lyell to account for the Glacial epoch is practically the same. Great elevation and depression of extensive areas can be effected only in thousands of years, and those who support Lyell's theory are of opinion that the duration of the Glacial epoch must be taken to be about 200,000 years in order to account for all the geo- graphical and geological changes, which, according to them, were the principal causes of the Glacial period. But there are other geologists, of the same school, who hold that the Glacial period may not have lasted longer than about 20 to 25 thousand years. The difference between the two estimates

THE GLACIAL PERIOD. 27 is enormous; but in the present state of geological evidence it is difficult to decide in favour of any one of these views. All that we can safely say is that the duration of the Pleistocene period, which included at least two Glacial and one Inter-Glacial epoch, must have been very much longer than the period of time which has elapsed since the commencement of the Post-Glacial period. According to Sir Robert Ball the whole difficulty of finding out the causes of the Glacial period vanishes when the solution of the problem is sought for in astronomy rather than in geography. Changes which seem to be so gigantic on the globe are, it is said, but daily wrought by cosmical forces with which we are familiar in astronomy, and one of the chief merits of Croll's theory is supposed to consist in the fact that it satisfactorily accunts for a succession of Glacial and Inter-Glacial epochs during the Pleisto- cene period. Dr. Croll in his Climate and Time and Climate and Cosmology has tried to explain and establish his theory by elaborate calculations, showing that the changes in the values of the variable elements in the motion of the earth round the sun can adequately account for the climatic changes in the Pleistocene period. We shall first briefly state Dr. Croll's theory, and then give the opinions of experts as regards its probability. Let PQ'AQ represent the orbit of the earth round the sun. This orbit is an ellipse, and the sun, instead of being in the centre C, is in one of the focii S or s. Let the sun be at S. Then the distance of the sun from the earth when the latter is at P would be the shortest, while, when the earth is at A it will be the longest. These points P and A are respectively called perihelion and aphelion. The seasons are caused, as stated above, by the axis of the earth being inclined to the plane of its orbit. Thus when the earth is at P and the axis turned away from the sun, it will produce