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Moreover, apart from the special influence of religion, the 'temperate' man perceives that the Divine economy, seen in Nature itself, is marked throughout by compromise,' and the balance of one law against another. Without affecting any claim to minute scientific perception he can see that there are powers and influences operating in the conduct of the world, any one of which, if uncontrolled, would be fatal to human life. And yet this does not prohibit the Creator from employing them in providing for the right condition of man. Thus temperance' in using and controlling those factors of mortal existence which are hurtful if unlimited in application, would seem to be a nearer approach to divine procedure than a complete rejection of them lest they should do mischief.

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In taking this line the temperate' man does not admit that he is anywise less sincere in his abhorrence of drunkenness than the total abstainer, nor that his method and hopes are less radically promising and sound. He bases them upon the great laws of life which cannot be broken without significant suffering, and he believes that the gradual recognition of these is sure to help and test not only the true progress of science and religion, but the conduct of individual life.

HARRY JONES.

1896

THE WORLD BENEATH THE OCEAN

THE book which Dr. Nansen is writing for Archibald Constable & Co. descriptive of his recent expedition will be eagerly awaited by all who are interested in the study of oceanography. In the somewhat discursive and, to all appearance, hastily written papers which appeared in the Daily Chronicle the Norwegian explorer only touched lightly on the observations which he had made in connection with this subject. We learn, however, that he took a large number of soundings, and concluded, from the remarkable absence of organic life in the samples brought up from the bottom, that the existing views as to the nature of ocean-bed deposits will have to be modified. 'No doubt the majority of these soundings were taken with reliable sounding machinery, and not by a line running over a block and recovered by hand, as represented in the sketch accompanying his paper. A word will be said later in this article with regard to the depths and temperatures which he gives.

All observations that add to our knowledge of ocean depths and deposits are of special interest at the present time, when a conference is being held at the Colonial Office concerning the laying of a Pacific cable in depths which will exceed those of the deepest cable already laid, and in deposits of which no practical experience has been gained. It is only since surveys of the sea bottom were first undertaken for the purposes of submarine telegraphy that any knowledge has been gained of the world beneath the ocean. A certain acquaintance, it is true, with marine animals in shallow waters has long existed, and Aristotle, who mentions 180 species in the Egean Sea, is familiar to the student of natural history in connection with the masticatory organ of the Echinus, or sea-hedgehog, called after the great philosopher Aristotle's Lantern.' Some four hundred years later Pliny the Elder enumerates 176 species, which, although four less than Aristotle's list, seemed to afford the gossipy old naturalist very lively satisfaction. One must allow,' he says, 'that it is quite impossible to comprise every species of terrestrial animal in one general view for the information of mankind, and yet, by Hercules! in the sea and

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VOL. XL-No. 238

881

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ocean, vast as it is, there exists nothing that is unknown to us; and -a truly marvellous fact-it is with those things which nature has concealed in the deep that we are best acquainted.' Pliny's selfcongratulatory vein would have been brought to a speedy termination if he had known that the complete list included 500,000 species, though it is only fair to say that 400,000 of them are organisms very low down in the scale of nature.

The discovery of America and the extended voyages which followed it stimulated interest in matters connected with the ocean. Sir John Hawkins, the great Elizabethan admiral, believed that if it were not for the movement of the sea by tides and winds, it would corrupt the world. This theory was based on an experience off the Azores, where he was becalmed six months. He relates that the sea was filled with serpents, adders, and snakes, three to six feet long, some green, some black, some yellow, some white,' and so numerous 'that hardly a man could draw a bucket clear of some corruption.' Is it possible that this account suggested Coleridge's well-known lines in the Ancient Mariner?—

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The very sea did rot; O Christ!

That ever this should be!.

Yea, slimy things did crawl with legs
Upon the slimy sea.

No scientific attempts to take deep-sea soundings were made before the seventeenth century. Then Hooke employed a sphere of wood, well pitched and varnished, which was sunk by a sphere of iron attached to it by a spring hook. On reaching the bottom the sphere of wood became released and rose to the surface, the depth of the sounding being calculated by a formula from the interval between the time when it was let go and the time when it appeared again. In 1733 two members of the Royal Society, Dr. Stephen Hales and Dr. Desaguliers, invented a scunder consisting of a glass vessel in which stood a gauge-tube, the top of which was hermetically sealed, while the bottom was immersed in mercury, covered with a thin film of treacle. The mode of sinking, as in Hooke's sounder, was by a weight, which became detached on reaching the bottom. The pressure of the water forced the mercury up the glass gauge-tube, and the treacle marked the highest point reached. The depth was calculated by Boyle's law of pressure. A hollow sphere attached to the top of the glass vessel caused it to rise to the surface when the weight was released. This contrivance of the two learned doctors acted very well in shallow water, where there was little current, but would have been useless in great depths, where the pressure would burst the hollow sphere, or in currents strong enough to carry it out of sight. The interest of their invention lies in the fact that it anticipated by some hundred and fifty years Lord Kelvin's sounding tube, which depends

on the same principle, and which is of such great service in modern navigation.

Little advance was made in oceanography during the eighteenth century, but in 1818 Sir John Ross in his famous Arctic expedition brought up living specimens from a depth of 1,050 fathoms,' by means of a hemp line and a deep-sea clamm, resembling in appearance a self-acting pair of tongs, with large spoon-shaped ends. This achievement was regarded with suspicion by eminent zoologists, and as late as 1859 Edward Forbes, in his Natural History of European Seas, insisted on the theory that animal life could not exist at greater depths than 300 or 400 fathoms. The theory was destined to receive a rude shock the following year in the course of some soundings taken by H.M.S. Bulldog over a proposed route for the Atlantic cable. During the first portion of the voyage the specimens recovered from the sea bottom were of little interest. But at length striking results were obtained from a sounding in 1,260 fathoms. One can judge of the scientific enthusiasm which the problem aroused by the tone in which Dr. Wallich, the chief naturalist on board, describes the occasion: That single sounding, I may be permitted to say, compensated for every disappointment that weather and accident may have previously engendered. At the eleventh hour, and under circumstances the most unfavourable for searching out its secrets, the deep has sent forth the long-coveted message.'

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This message consisted of thirteen starfishes, which had become attached to the end of the line as it rested for a short time on the ocean bed. Its announcement was followed by a storm of controversy amongst the scientific men of the day. The idea of a bathymetric line, or life-zero, below which animal existence could not be supported, was not easily abandoned by the partisans of Edward Forbes. They declared that the starfishes came from a higher layer of water, and had 'convulsively embraced' the line on its way from the bottom. But the question was settled beyond all doubt in the latter part of the same year, when a Mediterranean cable, which Professor Fleeming Jenkin hooked from a depth of over 1,000 fathoms for the purpose of repair, came up with evidences of animal life encrusted on its sheathing.

Meanwhile the science of deep-sea sounding had made considerable advances owing to a contrivance invented in 1854 by Brooke, an officer in the United States Navy. Hitherto no sinking weight had been attached to the sounder, and in great depths the increased friction on the line made the rate of descent so slow, that on reaching the bottom there was no perceptible diminution in the speed of running out, the line continuing to descend by its own weight. On one occasion

1 One fathom being 6 feet, 1,000 fathoms is slightly more than 14 of a statute mile. Throughout this paper depths and lengths are given in statute, not in nautical, miles.

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Captain Denham paid out 7,706 fathoms, or 84 miles, without getting bottom, and from another ship over 8,300 fathoms, or 10 miles, of line were lowered with the same result. Brooke's invention depended on the same principle as that employed by Hooke two hundred years previously, namely, that of a heavy weight to sink the sounder, the weight becoming detached automatically on reaching the bottom. The difference in the two methods consists in the fact that, instead of a sphere of wood, Brooke used a metal tube, which was lowered and recovered by means of a hemp line. The weight was a large shot or cannon ball with a hole through the centre, by which it was passed over the sounding tube, and suspended in that position by hanging from two metal arms pivoted to the top of the tube. These arms were attached by a looped cord to the hemp line, and during descent were kept upright by the weight of the sounder. On reaching the bottom the strain was removed, the two arms dropped, and the weight slipped off, leaving the sounder free to return by itself.

But, in spite of the heavy weights employed, hemp lines could not be relied upon in deep water where strong currents were present, and in the case of the Gulf Stream it was found almost impossible to get bottom with them. Accordingly, in 1872, Sir William Thomson, now Lord Kelvin, made some experiments with the view of replacing hemp by wire. As far back as 1838 wire had been used for sounding purposes, but it was of so heavy a type that no indication of reaching the bottom could be observed. The type employed by Lord Kelvin was ordinary pianoforte wire, and proved a complete success. The kind now in general use is only of an inch in diameter, and has a breaking strain of 270 lb., or over 19 stone, which is, bulk for bulk, eighteen times as great as that of hemp. On account of its smooth surface and small area it offers extremely small resistance to the water, and gives accurate results in the strongest currents. But it is in the recovery that, owing to its small weight, which is only 13 lb. per mile, the superiority of this wire is most apparent. A length of 2,000 fathoms, or 24 miles, can be wound in-even when the ship has started and is steaming eight or nine knots-in twentytwo minutes, that is, at the rate of 540 feet a minute, which is very little slower than the rate of paying out. A similar length of hemp line would take 2 hours to recover, and this could only be done when the ship was stationary. In temperature soundings, however, it is unwise to trust to a single wire the weight of a series of thermometers, and for this purpose a wire cable, 2.25 mm. or about of an inch in diameter, such as H.S.H. the Prince of Monaco uses on board the Princess Alice, is the best.

There have been many different forms of sounders, but the one now used by the Silvertown Cable Company presents the most important features of the majority, and may be taken as a typical one. It is an adaptation of Sigsbee's sounder, and consists of a central

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