Art. IX.—Antarctic Research.
[Read before the Wellington Philosophical Society, 31st July, 1895.]
In the year 1887 a proposal was made to the British Government by the Government of Victoria that an expedition should be undertaken to explore the antarctic regions, at an estimated cost of £10,000, of which sum the Victorian Government guaranteed to provide £5,000 if the British Government would provide the remaining £5,000. The proposal was not favourably entertained. The objects of the expedition, as defined by the Victorian Government, were—first, the promotion of trade; and second, scientific inquiry. The Lords Commissioners of Her Majesty's Treasury stated in their reply, “The department best able to judge of the first does not think the interests involved sufficient to justify the proposed Imperial contribution; and the general result of the communications regarding the second object received from scientific bodies is to show that an expedition on the scale contemplated could do very little in the way of scientific investigation, and would have to be regarded simply as a pioneer of future more complete and costly expeditions.” For these reasons they felt they would not be warranted in asking Parliament to provide the proposed contribution; and
they went on to say they “arrive at this conclusion, however, with sincere regret, and would have been glad to have co-operated with the Australian Colonies in an enterprise having something more than a merely commercial purpose. Perhaps, however, my Lords may be allowed to regard the present proposal as an indication that if any like expedition be undertaken hereafter by the Imperial Government some of the British colonies more closely interested in it might not be unwilling to contribute to its cost.”
This proposed expedition, therefore, was abandoned, and the subject dropped out of notice, until it was revived by Dr. John Murray, one of the distinguished members of the late “Challenger” expedition, in a paper read by him before the Royal Geographical Society on the 27th November, 1893.
In this most valuable and exhaustive paper he related the history of antarctic explorations. He showed that Captain Cook was the first to penetrate within the antarctic circle, having reached lat. 71° 10′ S., at a point to the south-west of Patagonia, “when he probably saw the ice-barrier and the mountains beyond.” This was in his second voyage, in 1774, after his circumnavigation of New Zealand in his first voyage. Since then two navigators have penetrated further south than Cook: “Weddell, in 1823, reached 74° S., but saw no land. Sir James Clark Ross, in 1841 and 1842, reached the 78th parallel, and discovered Victoria Land, south of New Zealand. No other explorers have passed beyond the 70th parallel of south latitude.”
In the course of his paper Dr. Murray referred to the explorations carried out under Smith in 1819, who discovered the South Shetland Islands, and the consequent seal-fishery which sprang up, and resulted in the extermination of the seals. Bellingshausen discovered the island named Peter the Great, and Alexander the First Land; D'Urville discovered Adélie Land; the United States Exploring Expedition discovered Wilkes Land; Powell discovered the South Orkneys; Briscoe discovered Enderby's Land; Balleny discovered the Balleny Islands and Sabine Land; and Dallman, more re-rently, discovered Kaiser Wilhelm Islands and Bismarck Strait, to the north of Graham's Land. Dr. Murray gave unstinted praise to the good work done by these and other explorers, who, with vessels unstrengthened to resist ice, and with imperfect means, have added so much to our knowledge of antarctic regions; but he pointed out that Ross's expedition, which was better provided, and the vessels well strengthened, was, under its splendid commander, able to do more than any other; and his observations on the geology, meteorology, and magnetic phenomena of those regions, as
well as his soundings and dredgings, and observations on currents and sea-temperatures at different depths, threw a flood of new light on the physical and biological conditions within the antarctic circle; but his ships were unprovided with steam-power, like those of all other antarctic explorers; and this is extremely disadvantageous, because the vessels are unable to make progress during the all-too-scanty periods of fine, calm weather; contrary winds in ice-encumbered waters are very perplexing and dangerous, and to anchor near an icebound coast while exploring parties are sent ashore is too risky for sailing-vessels.
The “Challenger” is the only steam-vessel that has crossed the antarctic circle, and, as she was not strengthened to bear the blows and pressure of ice, she could do little in the way of exploration through the pack, and was obliged to confine the observations to deep-sea soundings.
Putting together all the various results of the observations that have been made, Dr. Murray has prepared various maps of the southern pole (partially reproduced), in which he has shown what parts of the coast-line of antarctic land have been fixed, and these he has connected by dotted lines indicating the probable shape of the great antarctic continent which, from all indications, he presumes to exist, surrounding the south pole, about 3,500 miles long by 1,500 miles broad, and covered with perpetual snow and ice. He indicates also the approximate position assigned to the magnetic pole or poles, and the known and supposititious mean barometric pressures—the lowest (28.9in.) being in February, off Victoria Land, near Mounts Erebus and Terror. From the observed preponderance of southerly winds he assumes that a region of high barometric pressure exists around the South Pole.
The depths of the ocean, as far as they are known, are also figured, and in his paper he draws attention to the remarkable fact that the temperature at the bottom, even at the depth of over 2,000 fathoms, is not below 33° Fahr., while at the surface it may fall to 29°, and at an intermediate depth may be as high as 40°. The abundance of life now existing in these Antarctic-Ocean depths is very notable, and specimens of fossils, apparently of Tertiary age, obtained on Seymour Island by a Norwegian whaler indicate that at one period of the world's history a more genial climate must have prevailed in those regions.
Dr. Murray's maps further give the oceanic deposits in the different areas of the south polar seas; the ice-limits and currents; the mean temperatures or isotherms, and the isobars and winds, for February; the annual mean rainfall; and the magnetic phenomena (after Neumayer).
Owing to the snowcap which envelopes the great antarctic land mass, the nucleus of rock is only revealed in off-lying islands or on the faces of high and bold escarpments, or by the fragments of rock carried seawards by icebergs, and either obtained directly from them or dredged from the sea-bottom where they have been dropped by the icebergs as they melted. Thus the geology of the country is mainly concealed from view; but the outlines and larger features of the mountain-ranges are not obliterated in the high lands near the coasts, for peak after peak with varied contours are seen to rise one behind another towards the interior. The snow which accumulates on these mountain-ranges in Victoria Land forms a vast glacier, which moves continually outwards, and presents on the coast-line a solid perpendicular wall of ice, probably from 1,200ft. to 1,500ft. in thickness, of which 150ft. to 200ft. is above the surface of the water and 1,100ft. to 1,400ft. below. When the front of this great glacier reaches depths of 300 to 400 fathoms large stretches break off and float away, forming the perpendicular-faced, horizontally-stratified, table-topped icebergs of the Antarctic and Southern Oceans. Fragments broken from these great ice-islands by collisions, mixed with salt-water ice, and accumulations of snow, form what is known as the “pack,” which at favourable times and places can be penetrated by properly-protected vessels; but the great ice-wall, along which Ross coasted for three hundred miles east and west, is an absolute barrier to ships, although there are places where a landing might be effected and a winter station be formed, and one such place was noted by Ross, near Mount Erebus, and within a comparatively short distance of the magnetic pole, or where we have reason for supposing that pole to be.
Dr. Murray refers to the results of the deep-sea dredging carried out by the “Challenger” expedition, and states, “All over the floor of the Antarctic Ocean there is a most abundant fauna, apparently more abundant than in any other region of the ocean's bed. In one haul made by the “Challenger,” in a depth of two miles, in lat. 47° S., the trawl brought up (excluding Protozoa) over two hundred specimens belonging to eighty-nine species of animals, of which seventy-three were new to science, including representatives of twenty-eight new genera.” He says, “It is most probable—indeed, almost certain—that the floor of the ocean as well as all pelagic waters have been peopled from the shallow waters surrounding continental land, and here in the deep waters of the Antarctic we appear to have very clear indications of the existence of the descendants of animals that once inhabited the shallow waters along the shores of Antarctica, while in other regions of the ocean the descendants of the shallow-
water organisms of the northern continents prevail. This is a subject of great interest to all biologists, and can best be studied by a more efficient exploration of these southern latitudes.”
The objects for which a renewed effort to explore the unknown regions in the vicinity of the southern pole should now be undertaken were summarised by Dr. John Murray as follows:—
“To determine the nature and extent of the Antarctic Continent; to penetrate into the interior; to ascertain the depth and nature of the ice-cap; to observe the character of the underlying rocks and their fossils; to take magnetical and meteorological observations, both at sea and on land; to observe the temperature of the ocean at all depths and seasons of the year; to take pendulum observations on land, and possibly also to make gravity observations at great depths in the ocean; to bore through the deposits on the floor of the ocean at certain points to ascertain the condition of the deeper layers*; to sound, trawl, and dredge, and study the character of marine organisms—all this would be the work of a modern antarctic expedition. For the more definite determination of the distribution of land and water on our planet; for the solution of many problems concerning the Ice Age; for the better determination of the internal constitution and superficial form of the earth; for a more complete knowledge of the laws which govern the motions of the atmosphere and the hydrosphere; for more trustworthy indications as to the origin of terrestrial and marine plants and animals—all these observations are earnestly demanded by the science of our day.”
Dr. Murray's paper was fully discussed, and in a most favourable manner. All agreed that there was no probability of any commercial advantages resulting from antarctic explorations in the way of seal-hunting or whaling; but that the scientific knowledge to be gained would be of the very greatest value. The words of the President in summing up the discussion embody the feelings of the Council and members of the Royal Geographical Society. He said,—
“I consider that Dr. Murray's paper, and the important discussion which has followed it, will form a new starting-point in the advocacy of a renewal of antarctic discovery. We must not forget the valuable work that was done by Admiral Sir Erasmus Ommaney and the committee of the British Association five years ago. Sir Erasmus enlisted the
[Footnote] * “Dr. Murray believes that gravity determinations might be made, as well as the deposits bored into by specially-constructed instruments let down to the bottom from the ships.”
sympathies of the Royal Society, and even of the more enlightened members of the late Government. We owe him our warmest thanks for his exertions. Nor must we forget the zealous labours of Baron von Mueller, Captain Pascoe, and our other friends in Australia. They have long worked for the good cause of antarctic discovery, and I am confident that they will continue to exert all their influence in its favour. Our illustrious gold-medallist, Baron Nordenskiöld, the discoverer of the North-east Passage, has but now written me a cheery and encouraging letter, from which the following is an extract: ‘We shall follow the proceedings of an English expedition to those regions with the utmost interest, and with our best wishes for its success. It seems to me that the most important geographical problem for the moment is a systematic exploration of the hydrographic, meteorological, geological, and biological conditions of the antarctic regions. The arctic regions are in this respect now tolerably well known; but almost every scientific result gained from thence has given rise to new problems of the utmost importance for the better knowledge of our globe, which can only be satisfactorily answered by corresponding discoveries in the far south.’
“These inspiriting words will cheer us on in our task—a task from which I for one will never swerve until it is completed. I have pleasure in announcing to you that our Council has this day appointed a committee for the purpose of reporting on the best means of achieving the objects of antarctic exploration. The whole question will be thoroughly examined and discussed, and it will be our business to convince the Press and the public of its importance. We are, of course, devoted to geographical research and to the interests of science, and we look upon these objects as a chief reason for despatching an expedition. But, as an Englishman, I feel that the great result of all will be the encouragement of that spirit of maritime enterprise which has ever distinguished the people of this country, and the keeping - alive of our glorious naval traditions. We are well assured that as soon as the country is with us in the advisability of despatching an antarctic expedition the Government will concur. We may therefore work on full of confidence and hope. We shall look on this evening as our starting-point. Dr. Murray has given us the route—he has done so in a way we shall not soon forget; and I speak the sentiments of every one present in this great assembly when I offer to him our most sincere and hearty thanks for his very able and important address.”
The Antarctic Committee above alluded to reported that “the importance of antarctic research, and the desirability of its renewal, are recognised by all scientific bodies at Home and
abroad”; that “one of the most important requirements is the taking of magnetic observations, as it is known that a considerable change has occurred in the magnetism of the earth during the last fifty years, and the exact position of the south magnetic pole is hardly even approximately ascertained.” “Other objects of an antarctic expedition would be deep-sea soundings, the temperature of the ocean at all depths, dredgings, the study of the character and distribution of marine organisms, meteorology, and pendulum observations, if considered necessary; to explore the land as far as possible; to determine the limits of freezing in antarctic regions in the summer, and the direction of winds and currents, and the consequent formation and movements of the pack ice.”
They observed that our knowledge is still very incomplete of the antarctic winds and currents. South of 40° S. there is very low atmospheric pressure, with strong westerly winds and a large rainfall and snowfall, all round the globe. Such observations as we possess show that the winds in higher southern latitudes are, on the contrary, generally from the south and south-east, and the surface-currents are in the same direction, so that in the summer the pack and the bergs are continually drifted northwards. They showed the immense advantages which steamers would have over sailing-vessels in these investigations, and gave their opinion that the operations should be carried out by the Royal Navy in two vessels as well strengthened as were the “Erebus” and “Terror,” fitted with steam-power, and specially protected aft to guard the rudder and propeller.
The Royal Society, to whom the subject was referred, also appointed a special Antarctic Committee, who reported strongly in favour of an exploring expedition.
With regard to pendulum experiments, which were recommended (with reserve) by the Royal Geographical Society, but not directly alluded to by the Royal Society, it is to be observed that they were recommended by Dr. Murray; and in an appendix to his paper appears a communication from Dr. Neumayer, of the Hamburg Naval Observatory, who, after showing how exceedingly important are an examination and a survey of the magnetic properties of the antarctic region, goes on to note that the determination of the constant of gravity has never been carried out in that region, and but a very small number of determinations have been made even in the Southern Hemisphere south of lat. 33°. He gives a table containing all that is known with respect to this important question within the assigned region. To this table I have added the value of gravity corresponding with the lengths of the seconds-pendulum, as given in his table, and a few comparative values in the Northern Hemisphere:—
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|Length of Pendulum vibrating Seconds|
|Place.||Reduced to Sea-level.||Reduced to 45° Latitude.||Latitude S.||Value of G.||Value of G.||Latitude N.||Place.|
|Metres.||Metres.||Deg. min.||Foot Seconds.||Foot Seconds.||Dg.min.sec.|
|Port Jackson||2625||3625||33 57.6|
|Cape of Good Hope||2580||3673||33 56||32.140|
|Melbourne||2908||3561||37 49.9||32.142||32.1558||38 54 0||Washington, U.S.A.|
|Kerguelen Island||3645||3562||49 8.9||32.174||32.183||48 50 0||Paris.|
|Auckland Island||4026||3490||50 52||32.178|
|Falkland Islands (No. 1)||4154||3558||51 31.7||32.182*||32.191||51 29 0||Greenwich.|
|Falkland Islands (No. 2)||4077||3476||51 35.3||32.178*|
|South Georgia||4468||3608||54 31||32.191||32.196||53 21 0||Doublin.|
|Staaten Island||4501||3619||54 46.4||32.193||32.199||54 36 0||Belfast.|
|Cape Horn||4565||3590||55 51.3||32.1936||32.204||55 27 0||Edinburgh.|
|32.206||57 9 0||Aberdeen.|
|South Shetlands||5176||3631||62 56.2||32.212||32.217||60 45 0||Unst, North Shetlands.|
|† 32.221||62 45 0|
|32.2364||70 40 0||Hammerfest, Norway.|
|32.253||79 49 54||Spitzbergen.|
Dr. Neumayer goes on to say that, “as far as present evidence goes, there is an accordance of facts between the Northern and Southern Hemispheres with regard to the gravity determinations; but we must not forget that from within the
[Footnote] * Mean, 32.180.
[Footnote] † Interpolar.
south, polar circle not a single determination has been consulted, because there are none.” The accordance of gravity determinations obtained in the two hemispheres alluded to above has reference to the third column of the table, in which the length of the seconds-pendulum for each place, obtained by experiment, is used to calculate what should be the length of a seconds-pendulum in lat. 45° on the assumption that the earth is an ellipsoid of which the equatorial radius is 3962.802 miles and the polar radius is 3949.555 miles, and that the centre of gravity is at the centre of form. The values so obtained do not differ widely, and give a mean of 0.993577 metres—not far different from the computed length for 45°, nor from the ascertained length at Kerguelen, lat. 49° 8′ 9″. But it will be observed that there is a very notable difference in the values of G. at about the same latitudes in the two hemispheres, the force of gravity being greater in the Northern than in the Southern Hemisphere.
A comparison of the values in the two Shetlands, North and South, however, is the last that is at present available towards the poles, and it therefore appears of great scientific interest that further pendulum experiments should be made within the antarctic circle to determine the law of diminution of the force of gravity in the Southern Hemisphere.
The present state of our knowledge leads to the belief that the centre of gravity of the earth lies about three-tenths of a mile to the north of the equator. Such a condition of unsymmetrical balance of the earth, if it be established as a fact, may enable us to account for that slow gyration of the earth round an axis which is not the axis of the plane of the ecliptic, which has now been discovered to be the case; and I earnestly hope that pendulum experiments may form an integral part of the duties of the next antarctic expedition.
The centre of gravity being north of the equator, the plumb-line will be deflected there about 15″ from the true vertical, and astronomical observations by means of zenith distances will need correction. This additional means of measurement of the position of the centre of the earth's mass will, no doubt, be resorted to, so that astronomical observations may check those made by the pendulum.
The papers connected with the subject of a renewal of antarctic research have been forwarded by the President of the Royal Geographical Society to Sir James Hector for the consideration of the Council of the New Zealand Institute, with the expressed hope that they will use their influence with the New Zealand Government to give favourable consideration to the letters which have been addressed to their Agent-General by the Royal Geographical Society, and referring to
the Treasury letter previously quoted, in which the co-operation of the colonies interested was suggested.
Such co-operation, in the form of a small grant from each of the Australasian Colonies, would, it is believed, have such weight with the Imperial Government as to induce them to undertake the work at once; while the cordial feeling between the Mother-country and the colonies would be strengthened. The trade-routes between them would also be rendered safer by the increased knowledge of magnetic variations to be obtained.
The Council cordially welcomed the proposal, and I was requested to put before the members of the Wellington Philosophical Society a précis of the communications from the Royal Geographical Society, which I have endeavoured to do in this paper.