“Southern Naval Magnetic Expedition” (704-10)
The preparation of the two vessels intended for this important expedition which we have noticed from time to time being now completed they are on the point of departure from Chatham and of course have attracted visiters [sic] from all parts to witness the proceedings. The vessels selected for this service are the Erebus, commanded by Capt. James Clark Ross[1] and the Terror[2] commanded by Comr. Crosier, the conduct of the expedition being in charge of the former officer. The vessels have received that strengthening by additional timber both inside and out which is so necessary to fortify them against the effects of encountering the ice: the wales are doubled with 8 inch oak plank and the bottom with plank of three inches; the lining of the hold is doubled with African teak, the planks crossing each other at right angles; the bulkheads are made water tight, and the upper deck is doubled with 3 inch fir plank, fearnought dipped in tallow being laid between. Indeed to enumerate all the preparations would lead us beyond our present limits.—The instruments for the scientific purposes of the expedition are as numerous and complete as to be expected in the present improved condition of science.—What those purposes are we shall leave our readers to learn from the annexed report of the President and Council of the Royal Society on the instructions to be prepared for Captain Ross.
But we shall probably give our readers a better idea of the fittings of the two vessels by first laying before them the following extract from the Literary Gazette.
The Erebus and Terror seem to be twin ships, alike in build, in colours, in masts and rigging, and, indeed, in every external appearance. An inexperienced eye could not tell the one from the other. The Erebus is about 370 tons; the Terror 340. In each the full complement of officers and men is 64—128 in all[3]. Nothing that the art of the shipwright could accomplish has been omitted to fit them for their perilous undertaking. Below, not only have the ribs been strengthened by transverse timbers, but these again have been interlaced by cross beams at certain angles, so as to offer resistance to any invading body, such as ice, which would require a mighty force to overcome. Thus internally powerful, beyond any former example, the outward hull has also been so shaped (curving from near the centre, something like the turning-off edge of a glass or tea-cup) as to throw the converging ice from the chain plates, and thus protect the rigging from being crushed or invaded. The deck, too, his double; and the whole has a compactness and firmness which gives assurance of security from the worst elements to which their gallant crews can ever be exposed. A spare rudder, which could be shipped immediately in case of accident to the other, is safely stowed amidships: each vessel is provided with eight boats, two of them whalers, and framed to encounter rough seas and weather in separate expeditions, to explore passages and lands where the ships cannot penetrate. Six guns are borne in each; viz. four six pounders, and two salute guns. The apparatus for keeping the vessels at an equable temperature is admirable, and consists of a square iron tube, above a foot in diameter, running all round the sides, and distributing a comfortable warmth to every berth in the ship. The ventilation is not less attended to. There are also stoves in the captains’ cabins and the gunroom messes[4] which adjoin; and the cooking conveniences are as ample and as fit for every purpose as they could be on shore. There is a large kettle to dissolve ice into fresh water; another for dressing salt meat, another for fish, another for fresh meat, and ovens for baking. The mates’ cabins are well constructed, and those for the officers to sleep in, though small, are arranged with all a seaman’s skill and dexterity in making much of a little. The sick berths are forward and so contrived that the invalids may be kept apart from the healthy, for their own sakes as well as for the general safety. Immense ice saws are ranged along the lower deck; some of them 30 or more feet long and looking like the jaws of sharks, competent to cut through any besetting adversary.
They are victualled with fresh provisons for three years; and pemmican and prepared meats in cases are stowed away in the least possible compass.
The provision of scientific instruments, under the superintendance [sic] of the Royal Society, is very complete; and double sets, to supply the loss of any which may be broken, or rendered useless, seem almost to furnish the commander’s cabin. In this respect, the Admiralty has been most liberal; and, indeed, we may say, that after the first official difficulties were got over, the Government has taken up the expedition with the most commendable spirit, and done every thing that can contribute to its successful issue. The phenomena of terrestial magnetism will be independently observed throughout the voyage; and also in connection with the new observatories about to be established, as already stated in the Literary Gazette, at St. Helena, the Cape, Van Diemen’s Land, &c. The declination,[5] inclination, and intensity of the magnet, will thus form tables of the utmost importance towards solving this great problem. The declination instrument, the horizontal and the vertical force magnetometers, are constructed under the direction of Professor Lloyd, of Dublin; and there are, besides, dip circles, transits with azimuth circles, and chronometers of the most approved construction. There are also pendulums for ascertaining the true figure of the earth; thermometers for determining the temperature of the sea at given depths; other blackened thermometers to measure the atmospheric temperature at different latitudes; photometric sensitive paper, for experiments on light; barometers to be observed during storms, white squalls; glasses for sidereal observations (particularly on the variable stars Hydra and Argus); drawing utensils; repositories for geological, botanical, and natural history specimens; actinometers for finding the forces of solar and terrestrial radiation ; hygrometers, Osler’s anemometers, rain gauges, electrometers, skeleton registers of every needful kind; and, in short, such means to employ, and so much to be done, that there will be no great leisure for our enterprizing countrymen when all these instruments are put in requisition, and their results are regularly chronicled for the information of the world.
In looking over the vessels about to depart on so deeply interesting an occasion, many slight matters and incidents touch the feelings. In almost every cabin and berth were a tolerable collection of books; and Captain Ross’s amounted to a fair library of the most useful description. In some were sweet remembrances of native land, in prints and pictures; and one engraving conspicuous in the gallant commander’s cabin, affected us much—it was of our Saviour Walking on the Waters!! Faith and Hope could not have chosen a more beautiful illustration of the Sailor’s mind—the instruments of the soul, without the possession of which what were all that the philosophy and science of man could provide? In that engraving alone we read a more certain index of the successs of this great work, than in the multitude of ingenious machines, and the volumes of wise instructions, by which our most estimable friend was surrounded.
Some kind heart had supplied a twelfth-cake, to be opened on the 6th of January, 1840! The diameter of the globe will then be between the giver and the receiver.
Another pleasant circumstance to record is the friendship subsisting between Captain Ross and Com. Crozier. They have been messmates and intimate together. Crozier was a midshipman in the ship where Ross was a lieutenant: he was a lieutenant where Ross was captain, and now he is captain where Ross is commodore of the expedition. They have served together, know and regard each other, and this is an auspicious promise for their mutual good understanding and cordial co-operation to the end; when bound together in their brave barks—
“To reside
“In thrilling regions of thicked-ribbed ice,
“To be imprisoned in the viewless winds,
“And blown (we trust not) with restless violence round about
“The pendant world.
The earlier proceedings of the voyage will lead them to St. Helena, where Lieutenant Eardly Wilmot, of the Royal Engineers, who goes out in the Erebus, will be left in charge of the new Observatory. Next, at the Cape, will be landed for the like purpose, another officer. The vessels then make their way across the ocean, touching at and examining Kerguelen’s Land, Amsterdam, and other islands, either known or imperfectly reported in that vast expanse of waters. Arrived at Van Dieman’s Land, the instruments, &c. for the observatory will be sent ashore, and whilst it is erecting they will cruise to various points where the scientific pursuits of the expedition are most likely to be advanced. On their return, they will start de novo in a direct southern course, between 120 degrees and 160 degrees east longitude towards the Antarctic Pole; and it is a singular and fortunate thing that in this direction, during the present season, a ship of Mr. Enderby’s has discovered land on both sides of the longitudes we have indicated, in about 65 and 68 deg. of south latitude,[6] These shores have been named Sabrina Land, seen March 1839, and Balleny Isle, seen February, 1839; and between them, as well as upon them, the eiibrts of the Erebus arid Terror will, in the first instance, be employed. How far they may penetrate is in the hands of Providence. They will afterwards circumnavigate the Pole, and try in every quarter to reach the highest point, whether near Enderby’s Land, discoverd [sic] in 1832, or by Captain Weddell’s furthest reach about 74 degrees, in 1823.
It is between Sabrina Land and Balleny Isle, to the northward, in about latitude 50 degrees, and east longitude 140 degrees, that it is expected that the south magnetic pole will be found. Strange if he who discovered either that of the North or so near an approach to it as Captain James Ross did, should also ascertain this long sought phenomenon. We had forgotten to mention that the vessels are constructed on the plan which divides them into three compartments; so that either extremity or the middle might be stove in, and yet the remainder be a safe hold for the crew.
Wherever the voyagers go, we have only to add, may God bless and prosper them, and return them in safety to a grateful country and their anxious relatives and friends!
THE PRESIDENT AND COUNCIL OF THE ROYAL SOCIETY having recommended to Her Majesty’s Government the equipment of an Antarctic expedition for scientific objects, were informed by the Lords Commissioners of the Admiralty that it had been determined to send out Captain James Clark Ross on such an expedition, and the Council were at the same time requested to communicate to them, for their information, any suggestions on those subjects, or on other points to which they might wish Captain Ross’s attention to be called, in preparing the instructions to that officer.[7] The Council, having due regard to the magnitude and importance of the question, submitted to them, considered that they would best fulfil the wishes of Her Majesty’s Government, by a subdivision of the enquiry into different parts, and by referring the seperate consideration of each part to distinct Committees, consisting of those members of the Society who were especially conversant with the particular branches of science to which each division of the enquiry had relation. These several Committees, namely, those of Physics, of Meteorology, of Geology and Mineralogy, of Botany and Vegetable Physiology, and of Zoology and Animal Physiology, after bestowing much time and great attention in the investigation of the subjects brought under their notice, have each drawn up very full and complete Reports of the results of their labours. These reports have been considered and adopted by the Council, and have been incorporated in the following General Report, which the Council present as their opinion on the matters which have been referred to them by Her Majesty’s Government. They take this opportunity of declaring their satisfaction at the prospect of the benefits which are likely to accrue to science from the expedition thus liberally undertaken by the government on the representations made to them by the Royal Society and other scientific bodies in this country, and in conformity with a wise and enlightened policy. They also desire to express their grateful sense of the prompt attention which has been uniformly paid to their suggestions and of the ample provision which has been made for the accomplishment of the various objects of the expedition.
SECTION I.—PHYSICS AND METEOROLOGY.
The Council of the Royal Society are very strongly impressed with the number and importance of the desiderata in physical and meteorological science, which may wholly or in part be supplied by observations made under such highly favourably and encouraging circumstances as those afforded by the liberality of Her Majesty’s Government on this occasion. While they wish therefore to omit nothing in their enumeration of those objects which appear to them deserving of attentive inquiry on sound scientific grounds, and from which consequences may be drawn of real importance, either for the settlement of disputed questions, or for the advancement of knowledge in any of its branches, —they deem it equally their duty to omit or pass lightly over several points which, although not without a certain degree of interest, may yet be regarded in the present state of science rather as matters of abstract curiosity than as affording data for strict reasoning; as well as others, which may be equally well or better elucidated by enquiries instituted at home and at leisure.
I. Terrestrial Magnetism,—The subject of most importance, beyond all question, to which the attention of Captain James Clark Ross and his officers can be turned,—and that which must be considered as, in an emphatic manner, the great scientific object of the Expedition,—is that of Terrestrial Magnetism; and this will be considered: 1st, as regards those accessions to our knowledge which may be supplied by observations to be made during the progress of the Expedition, independently of any concert with or co-operation of other observers; and 2ndly, as regards those which depend on and require such concert; and are therefore to be considered with reference to the observations about to be carried on simultaneously in the fixed magnetic observatories, ordered to be established by Her Majesty’s Government with this especial view, and in the other similar observatories, both public and private, in Europe, India, and elsewhere, with which it is intended to open and maintain a correspondence.
Now it may be observed, that these two classes of observations naturally refer themselves to two chief branches into which the science of terrestrial magnetism in its present state subdivides itself, and which bear a certain analogy to the theories of the elliptic movements of the planets, and of their periodical and secular perturbations. The first comprehends the actual distribution of the magnetic influence over the globe, at the present epoch, in its mean or average state, when the effects of temporary fluctuations are either neglected or eliminated by extending the observations over a sufficient time to neutralize their effects. The other comprises the history of all that is not permanent in the phenomena, whether it appear in the form of momentary, daily, monthly, or annual change and restoration, or in progressive changes not compensated by counter changes, but going on continually accumulating in one direction, so as in the course of many years to alter the mean amount of the quantities observed. These last-mentioned changes hold the same place, in the analogy above alluded to, with respect to the mean quantities and temporary fluctuations, that the secular variations in the planetary movements must be regarded as holding, with respect to their mean orbits on the one hand, and their perturbations of brief period on the other.
There is, however, this difference, that in the planetary theory all these varieties of effect have been satisfactorily traced up to a single cause, whereas in that of terrestrial magnetism this is so far from being demonstrably the case, that the contrary is not destitute of considerable probability. In fact, the great features of the magnetic curves, and their general displacements and changes of form over the whole surface of the earth, would seem to be the result of causes acting in the interior of the earth, and pervading its whole mass; while the annual and diurnal variations of the needle, with their train of subordinate periodical movements, may, and very probably do arise from, and correspond to electric currents produced by periodical variations of temperature at its surface, due to the sun’s position above the horizon, or in the ecliptic, modified by local causes; while local or temporary electric discharges, due to thermic, chemical, or mechanical causes, acting in the higher regions of the atmosphere, and relieving themselves irregularly or at intervals, may serve to render account of those unceasing, and as they seem to us casual movements, which recent observations have placed in so conspicuous and interesting a light. The electrodynamic theory, which refers all magnetism to electric currents, is silent as to the causes of those currents, which may be various, and which only the analysis of their effects can teach us to regard as internal, superficial or atmospheric.
It is not merely for the use of the navigator that charts, giving a general view of the lines of Magnetic Declination, Inclination, and Intensity, are necessary. Such charts, could they really be depended on, and were they in any degree complete, would be of the most eminent use to the theoretical inquirer, not only as general directions in the choice of empirical formulæ, but as powerful instruments for facilitating numerical investigation, by the choice they afford of data favourably arranged; and above all, as affording decidedly the best means of comparing any given theory with observation. In fact, upon the whole the readiest, and beyond comparison the fairest and most effectual mode of testing the numerical applicability of a theory of terrestrial magnetism, would be, not servilely to calculate its results for given localities, however numerous, and thereby load its apparent errors with the real errors both of observation and of local magnetism; but to compare the totality of the lines in our charts with the corresponding lines, as they result from the formulæ to be tested, when their general agreement or disagreement will not only show how far the latter truly represents the facts, but will furnish distinct indications of the modifications they require.
Unfortunately for the progress of our theories, however, we are yet very far from possessing charts even of that one element, the Declination, most useful to the navigator, which satisfy these requisites; while as respects the others (the inclination and intensity) the most lamentable deficiencies occur, especially in the Antarctic regions. To make good these deficiencies by the continual practice of every mode of observation appropriate to the circumstances in which the observer is placed throughout the voyage, will be one of the great objects to which attention must be directed. And first—
To be continued.
[1] Nephew of Sir. John Ross and present in all the Northern expeditions.
[2] Recently commanded by Sir. George Back.
[3] Erebus.—Captain, J. C. Ross, Lieutenants, E. T. Bird, J. F. L. Wood,
J. Sibbald, Master. H. Mapleton, Surgeon, R. M’Cormick, Purser, T. R.
Hallett, Assistant Surgeon, J. D. Hooker.
Terror.—Captain, F. R. M. Crozier; Lieutenants, A. M’Murdo, J. H.
Kay; Master. P.P. Cotter; Surgeon, J. Robertson; Assistant Surgeon, D. Lyall.
[4] In these four officers will be accommodated, the fifth keeping the deck.
[5] For “Declination” read “Variation”, for “Inclanation” read “Dip” – Where is the necessity for deviation from oldterms. Ed. N.M.
[6] Of these recent discoveries in the southern hemisphere, Mr. Bates, of the
Poultry, has just published an excellent chart, under the superintendence of
Captain Beaufort. They appear like the pillars of a gateway, between
which the expedition should pass.
[7] This request was conveyed in a letter from Sir John Barrow, addressed to the Secretary of the Royal Society, and dated June 18, 1839.