时间:2019-12-12 08:53:32 作者:ppshw巧克力 浏览量:63855
Here and there Virgil gives us delightful little sea-cameos which show how keenly the ancients exulted in their ships, and raced them against each other past rock and cliff, through wind and spume. What, for example, could be more interesting than the account of the race of the four galleys in the fifth book of the ?neid? He gives you the names of the swift Pristis, the huge Chim?ra, which with her triple arrangement of oars was so big that she seemed like a floating town, the Centaur, and the dark blue Scylla. He draws for you the picture of the captains standing at the sterns, the crew taking their seats at the oars and waiting in eager breathlessness for the trumpet to83 start them on their race. Almost you can see the strong arms being drawn up to the breast and thrust smartly away again. The blue Scylla wins, but it is a splendid struggle. The little touches of the ship which was 鈥渟wifter than wind or flying arrow speeds towards land,鈥 and of the disabled galley which moves slowly (like to a snake which has been run over), yet hoists her canvas and enters the harbour鈥檚 mouth 鈥渨ith full sails,鈥 are pencilled in by a man who must have often watched a galley doing her work. He speaks of the lofty sterns which these galleys possessed, of Palinurus the pilot bidding his men to reef the sails at the gathering of a 鈥渄ark storm of rain, bringing with it gloom and foul weather,鈥 and gives orders to 鈥渓abour at their strong oars, and sidewards turn the sails to meet the wind.鈥 Evidently with the squall came a shift of wind, so that instead of being able to run with the breeze free, under sail power alone, they were now compelled to come on a wind, shorten canvas, and get out oars to prevent such shallow-draught vessels from drifting to leeward.177It is not my intention to digress from the path of historical continuity, but let the reader bear in mind how very little the navigator of this period had to help him. He had the compass for indicating the direction of the ship鈥檚 head, and he had the astrolabe and cross-staff for showing him his altitude. But two intensely important data he could not yet obtain accurately: (1) his longitude, and (2) the distance run by the ship in any given time. Very great errors were made in both178 of these. It was not until the introduction of the log-line in the seventeenth century that a ship could tell with even approximate accuracy her daily run. For many a long year all the cunning Jews and Arabs, all the philosophers, the astronomers and physicians, all the cleverest men out of Portugal, Spain, Genoa, Venice, and the Balearic Isles had tried but failed to solve this proposition. And the coming of the perfect chronometer for finding the longitude was delayed even longer still.
He goes into the subject with great thoroughness and points out that allowance must be made for the wind, and how to secure good aim. The cannon are to be placed so as to be right in the middle of the ports of the ship, and care is to be taken that the wheels of the gun-carriage are not made too high. He advises that when shooting from one ship at another, if there is any sea193 on it is essential to have a good helmsman 鈥渢hat can stirre steadie.鈥 The best time to fire at the other vessel is when the latter is 鈥渁lofte on the toppe of the sea,鈥 for then 鈥測ou have a bigger marke than when she is in the trough.鈥 If the ship rolls, 鈥渢hen the best place of the ship for to make a shotte is out of the head or sterne.鈥 The shorter ordnance is to be placed at the side of the ship because they are lighter, and if the ship should heave 鈥渨yth the bearyng of a Sayle that you must shutte the portes,鈥 then you can easily take the guns in.玄幻穿越小说排行榜 T易利go登入口And then, in 1765, the English prize was at last won by John and William Harrison, who were able to make instruments most suitable for this purpose, and received the 锟20,000. This was that invaluable little article the chronometer, which means so much to the modern mammoth steamships. Dr. Maskelyne, the Astronomer Royal, had, in 1754, discovered the method of finding longitude by lunar observations on shore. After navigators at last began to employ chronometers the dawn of modern methods had already occurred. In 1767 came the first publication of the 鈥淣autical Almanac,鈥 Hadley鈥檚 quadrant was made known in 1731, and the sextant in 1761. Perhaps, as the sailing masters in the Navy had to provide their own nautical instruments, there was not such an incentive to accustom themselves to new methods as might otherwise have been the case.易利go登入口Illustration to show an Elizabethan Helmsman Steering a Ship by means of Whipstaff.易利go登入口
易利go登入口The End易利go登入口After they have touched it with a needleHer timbers were found to have been cut with the grain, and every other one ran to the gunwale. A rubbing strake ran along outside the hull which took the thwart ends, the recesses for the same being still visible. It would appear as if the frames above turned outwards and formed a support for that gangway along which the soldiers were wont to fight. Some think there is evidence to show that the ship had a false keel, and that she carried a mast. As to the dimensions of the vessel, one authority, judging by the81 run of the stringer, suggests that when she was whole she measured about 90 feet long by 18 feet beam. The material was oak; the treenails, which were perfectly made and fitted, measured 1? inches in diameter.17易利go登入口
120But it is when we come to Pytheas of Massilia that we reach the border-line which separates fact from fable. This eminent astronomer and geographer of Marseilles brought together a knowledge of northern countries which was based not on premonition, not on speculation, not on hearsay, but on actual experience. So original, so accurate, and so far-reaching was his work, that for the next fifteen hundred years he dominated all geographical knowledge. We can fix his time if we remember that he flourished probably about the year 330 B.C. He was the first person in history to introduce astronomical measurements for ascertaining the geographical situation of a place, and thus became the founder of the science of navigation鈥攖he science which has enabled seas to be crossed in safety and continents to be discovered; which has given to the ship of all species a freedom to employ her speed without sacrificing safety. Indirectly arising from these may be traced the development and civilising and peopling of the world which have so entirely modified history.易利go登入口Great importance was clearly attached to the quinquiremes, for in such craft envoys, commissioners, or messengers of victory were carried. They fought together with the triremes and quadriremes as the capital ships of the Roman navy, and whilst the State depended on the treaty towns and allies for their lighter craft, yet the all-important quinquiremes were kept under immediate control. The description and arrangement of the different kinds of Greek warships is generally applicable to those of the Romans. On the deck of the galley the troops fought, while below them were the oarsmen. These propugnatores were protected by means of bulwarks (propugnacula) as well as by two wooden towers (turres), carried on supports which could be taken down from the ship whenever required.易利go登入口
鈥楽teward! cover the boorde anone,34易利go登入口And now that we have got some idea in our minds of the details of the seaman鈥檚 life on board an Elizabethan ship, let us be rowed off from the shore in one of her three boats which is bringing water and wood and provisions. The good ship is lying to her anchor in the roadstead about to get underway. Transport yourself, then, in imagination to that epoch when England鈥檚 seamen made such wonderful history, and endeavour to believe that the cock-boat actually bumps up alongside the English galleon. You clamber up the ship鈥檚 side and find yourself on her deck, where the crew are standing about ready to hear the commands of the master. And now let us watch them get under way. I shall quote not from fiction of to-day, but from an account written by an Elizabethan, this same Captain John Smith, as he wrote it for the edification of young seamen.易利go登入口There was something, then, so excellent in arrangement in these Ph?nician ships which seemed to Xenophon so superior to the vessels of his own countrymen; and the sailor-like neatness and systematic order were to him so striking that even to his disciplined and orderly mind they were most remarkable. It requires but little imagination to picture from this scant reference the ship鈥檚 company doing everything according to drill. The seaman-like care for the running gear on the part of the ship鈥檚 husband ready for any emergency is, indeed, highly suggestive.
Every modern deep-sea navigator is familiar with what is known as Great Circle Sailing. For the landsman it may be sufficient to explain that this principle seems to contradict Euclid鈥檚 assertion that the shortest distance between any two points is a straight line. In the case of a globe this statement of Euclid does not apply. Every steamer between Liverpool and New York to-day sails on a great circle for the most part of her passage. 鈥淕reat circles鈥 are those whose plane passes through the centre of the earth: for example, the Equator is a 鈥済reat circle.鈥 Now as far back as the year 1497 Pedro Nunez made the startling but true announcement that in sailing from one port to another the shortest course was along an arc of a great circle of the terrestrial sphere. And this fact was appreciated by such Elizabethan navigators as John Davis in his voyaging across the North Atlantic.重修之灭仙弑神续集 But there were some very fine fellows in two branches of the merchant service. Hutchinson calls attention to these: 鈥淭hose seamen in the coal and coasting trade to the city of London, are the most perfect in working and managing their ships in narrow, intricate, and difficult channels, and in tide ways; and the seamen in the East India trade are so in the open seas.鈥 鈥淭he best lessons for tacking and working to windward in little room,鈥 he remarks elsewhere, 鈥渁re in the colliers bound to London, where many great ships are constantly252 employed, and where wages are paid by the voyage, so that interest makes them dexterous.鈥 The mainmast of such craft stood further aft than was customary. Therefore they had a strong tendency to gripe, and so they often used their spritsail and all head sail for going to windward and making them manageable. In narrow channels, when the wind was blowing so strongly that all hands could not haul aft the fore sheet, this had to be done by the capstan. These little brigs had no lifts to the lower yards, no foretop bowlines, but short main bowlines, and snatch-blocks for the main and fore sheets. The main braces led forward so that the main and maintop bowlines were hauled and belayed to the same pin. 鈥淲e have ships,鈥 he says, 鈥渢hat will sail from six to nine miles an hour, upon a wind, when it blows fresh and the water is smooth, and will make their way good within six points of the wind, in still water, a third of what they run by the logg.鈥澮桌鹓o登入口易利go登入口Till the time when Hadley鈥檚 quadrant was adopted, masters had always stuck to Davis鈥. The ship鈥檚 time was still kept by half-hour glass. The quartermaster, when the sand had run down, capsized the glass again and struck the ship鈥檚 bell鈥攐n eight occasions during the256 watch. All the different courses sailed during a watch of four hours were marked by the quartermaster on a circular disc of hard wood. This was called a traverse board, and thereon were marked the different points of the compass. On the line of each point radiating from the centre were eight little holes, just as one sees in a cribbage-board. One at a time, pegs were placed into these holes to register the various courses sailed in every watch. And then, later on, the courses were entered on a log-book or slate, and the course and distance made good reckoned out.
易利go登入口If ever a fleet of ships was tried it was this expedition from the Devonshire village. They were not many days out and had not yet said farewell to the Bay of Biscay before they were caught in bad weather and the fleet scattered. But it is certain that this fleet140 accomplished what it did partly owing to the fact that every day at sea gave them greater experience, and partly because they were well found, or as well found as ever ships of that period could be. We can note the mind of a far-seeing man in the care with which these craft were fitted out. Thus, for example, in bad weather there was every chance of the steering oar being carried away or being broken into half. To guard against such an awkward possibility each ship went forth from the cliffs of Dartmouth with a number of spare steering oars. Another very likely article to carry away on a long voyage, involving bringing-up in all sorts of places, was the anchor. Each principal ship, therefore, carried no less than thirteen of such, though it should be added that of these some consisted of grapnels used in getting alongside the enemy and fighting hand to hand. There were spare oars also, two spare sails, three sets of halyards, stays, and other ropes鈥攅verything, in fact, except the mast and the ship鈥檚 boat was carried in duplicate. There were knights in armour, infantry, horses, and victuals for a whole year to be stowed away in these ships, so a great deal of thought had to be expended.鈥淚 must tell you, Socrates, what strikes me as the finest and most accurate arrangement of goods and furniture it was ever my fortune to set eyes on, when I went as a sightseer on board the great Ph?nician merchantman and beheld an endless quantity of goods and gear of all sorts, all separately packed and stowed away within the smallest compass. I need scarce remind you (he said, continuing his narrative) what a vast amount of wooden spars and cables a ship depends on in order to get to moorings; or again, in putting out to sea: you know the host of sails and cordage, rigging as they call it, she requires for sailing; the quantity of engines and machinery of all sorts she is armed with in case she should encounter any hostile craft; the infinitude of arms she carries, with her crew of fighting men aboard. Then all the vessels and utensils, such as people use at home on land, required for the different messes, form a portion of the freight; and besides all this, the hold is heavy laden with a mass of merchandise, the cargo proper, which the master carries with him for the sake of traffic. Well, all these different things that I have named lay packed there in a space but little larger than a fair-sized dining-room.25 The several sorts, moreover, as I noticed, lay so well arranged, there could be no entanglement of one with other, nor were searchers needed; and if all were snugly stowed, all were alike get-at-able, much to the avoidance of delay if anything were wanted on the instant. Then the pilot鈥檚 mate鈥攖he look-out man at the prow, to give him his proper title鈥攚as, I found, so well acquainted with the place for everything that, even off the ship, he could tell you where each set of things was laid and how many there were of each, just as well as anyone who knows his alphabet could tell you how many letters there are in Socrates, and the order in which they stand. I saw this same man (continued Ischomachus) examining at leisure everything which could possibly be needful for the service of the ship. His inspection caused me such surprise, I asked him what he was doing, whereupon he answered, 鈥業 am looking to see, stranger, in case anything should happen, how everything is arranged in the ship, and whether anything is wanting or not lying handy and shipshape. There is no time left, you know, when God makes a tempest in the great deep, to set about searching for what you want or to be giving out anything which is not snug and shipshape in its place.鈥欌22 15 W N W 14 N E by E This day at noone we departed from Silly.
As to the practical side of navigation, Bourne exhorted his mariners to remember that the earth is a globe and not a 鈥減latforme,鈥 as 鈥済enerally the most parte of the seamen make their account.鈥 The meridians, he reminded them, grow narrower towards the two poles. If one had occasion to voyage northward it were better to sail by the globe, he suggested. Therefore you should keep a perfect account of the ship鈥檚 course. Then resort to your globe and consider what place and parallel you are in (by means of the sun at day and the stars at night). Knowing where you are, set your globe to the elevation of your pole, and then turn to the place of your zenith and seek the opposite of it in your parallel, for then you know that in the same parallel is your east and west line. Then the just quarter of that circle to the pole must be divided into the eight points of your compass, doing so likewise on the other side.易利go登入口There were a number of small row-boats employed by the Vikings, the size of which did not allow of more than six oarsmen. No doubt these were employed for going ashore when the big ships lay some distance from the shore. But often the Viking craft lay alongside piers. 鈥淕unnstein said that now was the turn of the tide, and it was time to sail. Therewith they drew in their cables.... In this they fared on until they came to Geirsver, the first place where, coming from the north, one may lie at a pier. Thither they came both one day at eve, and lay in haven there off the pier.鈥 The mention is also made of gangways for getting on board from the shore.易利go登入口One of the most memorable battles in the whole of our naval history was that which is known as the 鈥淕lorious First of June,鈥 1794. The tactics which Howe employed on this occasion are interesting, because, although he formed his fleet in line-abreast, and was able to disable the enemy鈥檚 rear, forcing their van and centre to break away to support their rear, yet there was such a ship-to-ship mode of attack that it may seem to have been a reversion to the olden days of medievalism. But the reason for this was that Howe was well aware that, crew for crew, the English were superior to the French. The result proved that his belief was well grounded, for at this time the crisis in the British Navy had just passed, the improvement in tactics had taken place, and the decadent ebb had already run its course.易利go登入口