THE PHYSICAL GEOGRAPHY OF AUSTRALIA.'

By J. P. THOMSON, F. R. S. G. S.

In an anniversary address of this kind, it seems to me a first duty to acknowledge how deeply sensible I am of the honor you were pleased to confer upon me by unanimously electing me to the distinguished position of president of this society at last annual meeting. True it is that since the foundation of the society I had always endeavored to further the interests of our cause in every possible way during many years of actual self-denial, as honorary secretary, and there was, indeed, a time during an earlier period of our history when the secretarial duties were combined with those of treasurer and librarian. But these labors were lightened and enlivened by the love and enthusiasm that inspired them, by the support of a few personal friends, and by the hope that my adopted country and its rising generation would be benefited, both educationally and commercially, by a well-established national institution for the collation and dissemination of geographical knowledge. That my fondest hopes were not altogether in vain, nor the efforts so cheerfully given fruitless is, I think, clearly enough shown by the recognized position we now occupy among the scientific and literary institutions of the world, and by the splendid collections of valuable books and maps with which our library shelves are enriched. To the honest laborer for love, whether physical or mental, no other recompense is looked for than an inward consciousness of endeavoring to do good. Still, in the case of ourselves, we may fairly claim that our efforts have been amply justified by results. It seems to be a custom, sanctioned by usage, that the president of a society such as ours should have conceded to him the privilege of delivering an address to the members at the end of his term of office. That, in fact, appears to be the last act of a drama in which he has had to play the leading part— by no means an easy one, although in this case peculiarly pleasant. In my own case it must be confessed that a difficuly was experienced in the choice of a suitable subject, not but that there are several important and even interesting ones, more or less connected with the depart

1 Address to the Royal Geographical Society of Australasia, Brisbane, July 22, 1895. By the president, J. P. Thomson, F. R. S. G. S., F. S. Sc. (Lond.). Printed in Proceedings and Transactions, Vol. X.

ment of geography, in which I claim to take a deep interest, but it seemed to me undesirable to retraverse fields already occupied by my predecessors. At one time a presidential address was supposed to deal more or less with the work of the society during the preceding year, pointing out at the same time what had been done in its particular department in other parts of the world, with a plan for future operations. In some societies the practice is still followed out, but in my own opinion the wisdom of such a custom is open to doubt, and it is well to consider whether it is not better to deal with some local or special subject, leaving the operations of the society to be summarized in the report of the council, and the departmental work in other parts of the world to the special treatment of the older and larger societies. In this way the provincial bodies would act as tenders or feeders to the parent societies in Great Britain and the continent of Europe, supplying them with trustworthy local material for the department of national or universal geography. Such a recognized plan of action would doubtless result in universal federation of workers in the field of geographical science. It would also lead to a more thorough and exhaustive treatment of the various departmental subjects than they at present receive, and would result in uniformly organized, concerted, and systematic action in the field of labor.

On this occasion I shall endeavor to follow in the footsteps of one of my distinguished predecessors, Sir S. W. Griffith, who, in his very learned and interesting presidential address to this society in 1891, dealt with the "Political Geography of Australia."

To the native born, and to those whose homes and family ties naturally bind us all together in a common bond of union under the Southern Cross and the other beautiful constellations of the southern sky, there is no other country on the face of the earth so dearly beloved as Australia. None is certainly more important, and it is not to our credit as a people that while our school children are crammed with what after all is only a superficial and inadequate knowledge of all other parts of the world, little attention is given to our own country, to our industries, or to our natural and artificial resources. To the credit, be it said, of a public-spirited journal the subject of our national industries has recently received special treatment, and it is hoped the Courier, to which I particularly refer, will devote equal time and attention to other phases of our partially or wholly undeveloped resources. The Physical Geography of Australia demands fuller treatment than it has hitherto received by any society of this kind, for while we are always ready and anxious to extend our investigations over wide and remote fields the needs of our own country are too often overlooked. It is no doubt true that several parts of the interior of Australia are either wholly unknown or but imperfectly known. Enormous tracts of sterile and waterless country have baffled the efforts of many travelers to investigate the inland regions, and it is only quite recently that several important dis

coveries have been brought to our knowledge through the enlightened and patriotic enterprise of two South Australian gentlemen, Sir Thomas Elder and Mr. Horne, of Adelaide, who with praiseworthy liberality defrayed the cost of two separate and well-appointed scientific expedi tions to Central Australia. The absence or scarcity of reliable information concerning the more remote parts of the continent may no doubt account to some extent for the little attention hitherto bestowed upon its physical geography as a whole. As an example of how insignificantly Australia has, until very recent years, been regarded by intelligent and well-informed Europeans, I will just quote the concluding sentence of the introductory paragraph of an article in a standard work on geography, published in 1885, by Longmans & Co., of London: "But recent events have conferred upon Australia an importance which justifies our making it the subject of a distinct chapter."

A backward glance at what we assume to be the earliest stages of evolution of our continent, through successive geological ages, will enable us to realize more fully the distinct peculiarities of its physical aspect as well as of its past and present climatic conditions, as influenced by the various progressive steps of development. Let us commence with the Paleozoic period, during which we find a few raised disintegrated fragments of a submerged plateau projecting above the surface of the ocean. In Western Australia the dry land at this stage is represented by an elongated area extending from the twentieth parallel to the neighborhood of Swan River. The western or extreme outer fringe of this fragment now lies submerged outside of the present coast line, and consequently it forms a section of the ocean bed within the limits of the 1,200 to 6,000 foot contour line. A somewhat similar upheaved tongue-shaped area extended from Melville and Bathurst islands southward into Central Australia, and, like the former fragment, its northwest edge or shoulder is now submerged in the neighborhood of Anson's Bay within the 1,200-foot contour line. The remaining continental patches above water were represented by a few superficially small and isolated narrow elevations along the eastern seaboard of the continent, distributed over an extensive northerly and southerly range from Cape York Peninsula to the Australian Alps. These insulated fragments were, according to Prof. James Geikie, the Hon. A. C. Gregory, and other well-known authorities, the earliest representatives of this continent. The climate of this and other continental divisions of the globe must have possessed a remarkable uniformity of character throughout the whole area to which reference has been made. The areas of dry land being comparatively small, offered little impediment to the free circulation of ocean currents, and thus by the commingling of polar and equatorial waters an exceedingly mild and equable temperature was maintained. The succeeding stage of evolution was marked by the somewhat rapid and wide extension and unity of land areas. Insulated fragments increased in magnitude, assuming more

truly continental proportions during the Mesozoic era. A narrow belt of dry land, corresponding to the position of the Great Dividing Range, extended along the whole seaboard of Australia, uniting Tasmania, New Guinea, and Borneo. The whole western half of the continent was likewise raised above the surface of the ocean, curving westward to Java, Sumatra, and, effecting a junction with the eastern area at Borneo, stretched northerly to the southeast portion of India.1 Owing to this remarkable process of evolution, an enormous gulf or inland sea swept the whole central region of Australia, extending northerly and westerly to the southern shores of Borneo. The climate during this period was in like manner uniform, though less persistently marked than in earlier times. In the dawn of Tertiary times, Australia had become entirely continental or insulated. The connecting belts, which formerly uited it with neighboring counties, were submerged, and the inland waters were confined to a tract of submerged country in the neighborhood of the junction of the Murray and Darling rivers. Besides this the sea encroached upon the coast districts of the Gulf of Carpentaria, also upon a portion of the coast fringe in Western Australia, between Shark's Bay and Cape Leeuwyn, and a narrow section along the head of the Great Australian Bight was also submerged, but in all other respects the general conformation of our continent was almost identical then with what it is now. Contemporaneous with this physi cal change in the geographical aspect of the country a pronounced differentiation of climate occurred. Climatic zones possessing marked and distinctive characteristics existed, and in these mild seasonal changes prevailed. Although I have already remarked upon the uniformity of climate during the two preceding ages, still it seems reasonable to suppose that the atmospheric air was then more highly charged with moisture than we can at present conceive it to be, and that the rainfall in tropical and extra-tropical regions must have been enormous, owing to the widely distributed equatorial waters over vast areas of the globe, and the extensive circulation of ocean currents. It is worthy

It is not by any means improbable that during this age there was actually a land connection between Australia, New Zealand, the Antarctic Continent, and Patagonia. On a map accompanying a paper read before the Royal Geographical Society, and published in the Geographical Journal, January, 1894, Dr. John Murray shows that these lands are connected by a submerged plateau over which the soundings are very shallow, compared with the enormous depth of the neighboring ocean bed. The strongest evidence in support of this theory is, however, to be found among the fragmentary remains of extinct animals recently discovered in these now widely separated regions. In the Chatham Islands there have been found the remains of a large ocydromine rail and the fossil bones of a coote, allied to other extinct families that formerly inhabited Mauritius, and were probably distributed over a very wide geographical range of the southern hemisphere. There is also the occurrence of struthious birds in New Zealand, Queensland, Madagascar, and Patagonia, which seems to indicate that they were scattered about at a time when there were few impediments to interfere with their migratory movements over immensely wide areas, part of which is now occupied by the waters of the South Pacific Ocean.

of note that the predominating topographical features of the continent do not appear to have undergone any remarkable change during the successive stages of evolution under review. The dominant areas of elevation in all cases correspond throughout with the mountain ranges along the eastern seaboard, the Northern Territory, and Western Australia, while the central region is still charaterized by low and extensive desert-like salt-bush plains, dotted with shallow lakes and salt pans, and traversed by inland rivers. Configuration and position of land areas are two of the fundamental agents that operate in establishing and controlling the climatic zones of our globe, while their influence upon the distribution of rainfall is simply enormous. To enable us to study and understand the people of a country it becomes necessary and indeed indispensable to investigate the physical features and climate, for no other known agents exercise so powerful an influence on the grouping and migrations of the race as these, as well as in moulding and modifying classes and racial types. As compared with other countries, there is a decidedly marked defect in the physical geography of Australia. It possesses no remarkable mountains of high elevation, although the culminating peak of the Australian Alps is capped with snow for nearly all the year round. The highest ranges border the east coast line, extending in a more or less continuous chain from Wilson's Promontory in the south to Cape York in the north. Except the McPherson's Range, this great coastal chain of ranges is practically of no value in limiting or influencing the political divisions of the country, nor yet does it afford any very great impediment to or security against invasion. In most places it is easily accessible from the seaboard, and it possesses no narrow wild passes such as those that limit the great commercial inland trade routes in Europe, Asia, and America. One remarkable feature associated with the physical condition of the southeastern part of the continent is that the highest elevations correspond very closely with and occupy a position adjacent to the greatest depth of the ocean, which approaches closer to the southeast coast line. of Victoria than any other part of the continent.

The general plan or system of this eastern area of elevation may be briefly put in the following manner: From the main coastal range there radiate toward the interior numerous offshoots, or lateral spurs, as it were, and these form the watersheds of the inland rivers, as they are called, or streams that flow toward the interior. These outliers bear local designations, more or less appropriate, such as the Liverpool Range, New England Range, and Blue Mountains in New South Wales. The eastern face of the range approaches close to the coast line, and its waters are drained by several comparatively short but rapid rivers that frequently overflow their banks and inundate large areas of lowlying country during abnormal rainfalls. In Queensland there is probably a wider and more uniform distribution of elevated areas than in any other part of the continent. Here the elevations of the Coast