And men ashore have built great lights on wave-washed rocks and surf-pounded beaches, on mighty headlands and shoals of sand. Lightships mark the treacherous spots where lighthouses cannot be erected, and mark, as well, the entrances to many harbours around the world. And once past these the mariner is led into the shelter of the harbour between long lines of buoys, each telling him its message, each aiding him on his way. He rounds a rock in mid-channel unscathed, because a buoy anchored there tells him how to turn. He finds his anchorage because of other buoys, and perhaps he makes his ship fast to still another, and knows that once more the ocean has been crossed in safety and his voyage is ended.
Almost the whole of the surfaces of all the lands of earth bear the marks of man. Most people live their lives ashore amid nature that has been radically changed by man. Cities have been built, railroads flung across the land. Farms flourish and ploughs have turned up every inch of all their acres. A hundred years ago America was wild from the Alleghanies to the Pacific. Now one cannot cross it and be for more than a few minutes out of sight of signs of men.
But the ocean rolls ever on just as it rolled in prehistoric times. No mark that man has made has changed the sea. Yet, while man is unable to change one single thing about its solitary waste, he has marked its greater perils and has conquered it. The perils of the sea are growing ever less, and ships owe much of this to the lights that mark its danger spots.
CHAPTER XII
SHIP DESIGN, CONSTRUCTION, AND REPAIR
Ship design, prior to the opening of the 19th Century, was based very largely on rule-of-thumb methods. In ancient times, before Greece became a sea power, this was particularly true. Shipwrights and sailors came to know from experience what qualities were good and what were bad, and after many years at their work were able to construct ships with some understanding of what the ship could be expected to do.
It took only a little while for them to learn that narrow ships were easier to propel than broad ones but that broad ships possessed carrying power superior to that of narrow ones. Thus the merchant ships were “tubby” while warships were narrow. If a ship proved to be unseaworthy in heavy weather shipwrights naturally did not build other ships like her if they were looking particularly for seaworthiness. If a ship was able, it was only natural that her characteristics should be incorporated in other ships. If a ship otherwise satisfactory permitted seas to come aboard over bow or sides or stern, the sailors and shipwrights tried to correct the difficulty without losing her good qualities. Thus from generation to generation ships improved, although the process was slow.
When Greece was at her zenith there seems to have been a more thorough study made of structural design, and many things about ships were more or less standardized. Just how far the Greeks carried their study of ships it is impossible to say, but crude methods gave way to finer ones, and Greece passed its understanding of ships on to Carthage, and from the Carthaginians it went to Rome. But the Middle Ages lost this information, as it seems to have lost almost everything else, and a new beginning had to be made.
A SHIP ON THE WAYS
While a ship may look large on the water, she looks gigantic when on land. The great hulls and the collection of scaffolds and machinery in a shipyard are always a source of surprise to the visitor who is unfamiliar with the construction of ships.