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the Athenian people in irreverence and disbelief; and we would point our moral accordingly. Let those who complain of our criticisms reflect on the old characteristics of our poetry, its manly vigour, its healthy tone, and the simple dignity of its language. Let them compare with these qualities the softness and sentimentality of modern verse, its distorted representations of nature and unsocial views of life, its inclination to scepticism and sensuality, the luxurious effeminacy of its thought, the foppish singularity of its diction, and then say what effect this kind of art, the product of so-called philosophy, is likely to produce on the health of those who are constantly indulging in it. In common, we believe, with most Englishmen we repudiate the effeminate desires which Mr. Pater, the mouthpiece of our artistic culture,' would encourage in society. But such tastes can only be kept in check by repressing that analytical action of the imagination which Wordsworth conceived to be its true function, and which is the characteristic of almost all modern poetry. Poetry is the culture of the intellect through the feelings, not of the feelings through the intellect. So it has ever been in its best times; and in maintaining that, if it is to survive as an art, it must become so again, we are not calling for reaction. We have been represented as advocating a return to the 'style' of the eighteenth century; but this is entirely to misconceive the drift of our arguments. Much as we admire the genius of the century which produced the poetry of Pope and the criticism of Addison, for style itself we care nothing, except as the expression of genuine thought. But we say with the fullest faith that, if English society is to preserve its health, and the English language its purity, the whole spirit of modern poetry must be changed. Instead of making indiscriminate excursions into philosophy, producing nothing but fantastic forms and empty sound, we desire to see poetry directing the public imagination towards noble objects, and awaking the spirit of action by the charm of natural eloquence. And if these results are ever again to be achieved, we must reject the analytical spirit of Wordsworth, and revive the constructive spirit of Gray.
ART. V.-1. Voyage fait par ordre du Roi, en 1768-9, pour éprouver les Horloges marines de Berthould. Par D'E. de Fleurieu. Paris, 1773.
2. Dissertation on the Rise, &c., of Navigation. By Dr. James Wilson. (Prefixed to Robertson's Navigation, Wales's edition.) London, 1786.
3. Norie's Epitome of Navigation. Martin's edition. London,
4. Raper's Navigation. London. Sixth edition.
5. Shadwell on Chronometers. Admiral C. F. Shadwell, R.N., C.B. London, 1861.
N 22nd of Sir Shovel, Com
thender-in-Chief of the English fleet in the Mediterranean,
was returning home with his command, and lay to, uncertain of his position in the chops of the Channel. Ábout noon,' says his biographer, 'he hove to, but at six in the evening he made sail again and stood away under his courses, believing, as is supposed, that he saw the light on St. Agnes, one of the islands of Scilly.' Before daylight the Admiral's ship and several of the vessels of his fleet were wrecked upon the inhospitable shore, and a large number of the finest seamen in England perished with their chief. Such a signal disaster, occurring as it did to one of the most skilful sailors of that day, created no small stir; public attention was fully awakened to the fact that a British Admiral could lose his way almost within sight of home, and that because no means existed of surely ascertaining the position of his ship. After considerable discussion, during which the disaster to the Mediterranean fleet was pointedly referred to, an Act of Parliament was passed (12 Anne, cap. 15) granting 20007. for experiments to be made for ascertaining the best means of finding the longitude at sea, and offering a reward of 20,000l. to any one who should discover a method, applicable for use at sea, for discovering the longitude within a limit of error of sixty miles! *
Far different is the case at the present day. It is now possible for a ship to leave a particular spot in mid-ocean, not otherwise defined than by carefully designated latitude and longitude, and to return to it at any interval of time with such certainty as to be sure of her position within half a mile. This has been done time and again by the ships engaged in laying telegraph cables between England and America. Many times it has been necessary to cut the end of a cable and leave the spot; the rough weather which has rendered the temporary abandonment necessary has usually washed away the buoys which are affixed to the submerged end; but that is of little consequence, for astronomical and chronometrical observations are now so minutely accurate that no delay occurs in finding the exact position of the abandoned
The reward offered was to be proportionate to the success obtained. 10,0001. if the longitude could be determined within sixty miles; 20,000l. if it could be determined within thirty miles.
end, and fishing it up even from an ocean-depth of two miles or Nor is this precision a secret confined only to a few; large numbers of officers, whether in the service of the Queen or in the merchant navy, would be ready to start to-morrow, armed with the skill requisite to perform the same feat again.
It has been thought that so startling an improvement in the science of navigation deserves attention. An achievement which the last Parliament of Queen Anne considered so difficult that they offered a reward for its solution within sixty miles, can now easily be performed within the limits of error of a single mile. We have tried in the following pages to trace the course of progress which has made that apparent wonder possible.
The history of the art of navigation is a book still to be written. The materials are in many languages; all the maritime nations. have contributed their quota, the Spaniards, as might be expected, leading the way.
About the middle of the sixteenth century, Martin Cortez published at Seville a treatise on navigation, called 'Breve compendio de la Sphera, y de la Arte de Navegar,' which was translated into English: and about the same time one Pedro Nunez proposed a method for determining the latitude from two observations of the sun's altitude and the intermediate azimuth. But the method belonged too much to the realm of pure mathematics to be of much practical use, for in those days logarithms and traverse tables had no existence. At the close of the sixteenth century, Captain John Davis published his 'Seaman's Secrets.' He, like other authors who discoursed on navigation, complained of plane charts, then exclusively used, though he was unable to devise a remedy. Plane charts are those which treat the area represented as a flat surface; but as the practical measurement of the sphere became closer, the distortion of the truth became more and more apparent. It was then that Gerard Mercator devised, and Wright, Fellow of a Cambridge College, improved, the method of dividing charts, which is still in ordinary use under the name of 'Mercator's Projection.' After some tentative efforts, Mr. Wright printed his Correction of certain Errors in Navigation,' 1599, which puts the matter of charts substantially on the footing upon which it now stands. Mid-latitude sailing was introduced in 1623 by Gunter. And about the same time Lord Napier introduced logarithms, and, as far as nautical arithmetic is concerned, completely revolutionised the whole method of calculation. Henceforth long and tedious sums were replaced by easy problems in simple addition and subtraction.
In more recent days we have transactions of learned societies,
pamphlets only known to the curious, and controversies sometimes of a very angry character between philosophers, each claiming the paternity of some scientific bantling. Fortunately mariners have never been without a plentiful supply of textbooks, which, as they successively appeared, gave the newest improvements. By comparing the precepts of these teachers one with another, those who have the patience can trace a new idea from the state of a 'happy thought' to that of received and unquestioned formula, and determine the state of science at the date when each work appeared. As an instance of the way in which the landmarks of progress may be fixed by internal evidence, we may quote Dr. Robertson, one of the great authorities at the close of the last century, successively head master of the Royal Academy at Portsmouth and Librarian of the Royal Society. In describing the instruments used in his time for taking altitudes, he describes at great length the mode of dealing with one, called Davis's quadrant, in which the sun's rays were collected into a bright spot through a convex lens and made to fall upon the index in such a manner as to give the altitude. Now, we know that Hadley's reflecting quadrant was given to the world in 1731, or thereabouts; but of Hadley's quadrant Robertson, writing in 1786, says: Hadley's quadrants within a few years past having been applied to take the observations necessary for finding the longitude at sea, it has been found that such observations required a degree of accuracy of which the instruments constructed in the common way were not capable; and expert mariners having complained of these defects, different workmen have applied sundry articles to the quadrants to remedy the inconveniences complained of,' &c. In 1786, then, reflecting instruments, though perfectly well known in principle, had not yet supplanted the old Davis's quadrant. A few years later Davis's quadrant was as obsolete as the cross-staff of which Robertson speaks with a kind of regretful tenderness.
Before the invention of telescopes, astronomers, even on land, were compelled to content themselves with very rude appliances. Neither the astrolabe of Hipparchus, nor the graduated circle of Ptolemy, nor, indeed, the quadrant of Copernicus, were fitte for use at sea. The latter was, in fact, only a quarter of an astrolabe, such as had been used 150 years before Christ, enlarged for the purpose of more accurate division. Undoubtedly the cross-staff was the earliest instrument used in nautical astronomy. It consisted of a long arm, on which cross-pieces were made to slide in such a manner that the eye placed at the extremity of the
* Wales's edition of 1786, vol. ii. p. 252.
arm could see the heavenly body above and the horizon below the cross-piece. The cross-piece, as it moved along the arm, subtended angles varying according to its distance from the observer's eye; and the value of the angle was marked upon the arm. It must have been by no means easy for an observer to look alternately at the heavenly body and the horizon without losing the place of the one or the other. Some form of the cross-staff was known to Columbus, and it kept its place in the estimation of mariners till it was replaced by the back-staff, otherwise called Davis's quadrant, which in its turn was finally superseded by the reflecting instrument of Sir Isaac Newton. Davis, when he invented his quadrant, thought, and with amusing frankness asserted, that it was not only the best instrument yet invented, but the best that ever could be devised. . . . 'than which instrument (in my opinion) the seaman shall not finde anie so good, and in all clymates of so great certaintie, the invention and demonstration whereof I may boldly challenge to appertain unto myselfe (as a portion of the talent which God hath bestowed upon me) I hope without abuse or offence to any.' The French called the back-staff le quartier Anglois.
A description of Newton's invention was given by Sir Isaac . in a letter to his friend, Dr. Halley.* But the letter was not published till both Sir Isaac Newton and Halley were dead. Meanwhile, John Hadley, a friend of Newton's, had become acquainted with the principle of double reflection, on which Newton's quadrant was contrived. The reflecting quadrant bears, therefore, the name of Hadley as its inventor, though priority has been claimed in favour of a gentleman named Godfrey, a native of Pennsylvania. Whoever was the inventor, the instrument revolutionised the art of navigation, and successive improvements have so perfected it, that nothing better can be desired for use at sea, even for the precise observations necessary in modern navigation. The peculiar advantage of the reflecting quadrant over all instruments previously used at sea consists in its being capable of use during the tossing of a ship under way. In the reflecting sextant which is now used the observer looks straight at the horizon through a telescope, and a little opening called the horizon glass. On a movable limb, playing round the centre of the instrument, is fixed a mirror, which is moved till the image of the observed object is reflected on the silvered half of the horizon glass. The heavenly body and the horizon thus appear to touch each other, and the number of degrees through which the limb must be moved in order to
* Dr. James Wilson, in his Rise, &c., of Navigation,' fixes the date of this letter as A.D. 1700.