Such catastrophes are not uncommon in volcanic districts, where the ocean retorts with terrible vengeance when it is struck by the land. That appalling explosion in 1883 of Krakatoa, in the Strait of Sunda, was followed on neighboring coasts by a series of vast billows that rolled inland, deluging a wide extent of shore, sweeping away over 150 villages, and crushing or drowning more than 30,000 persons. Within a few years the coasts of northern Japan have been inundated repeatedly by earthquake waves with similar dire calamities, and they are likely to occur again. Now and then earthquakes are felt even in the open sea, far from land. Thus, Captain Lecky, a scientific writer upon the sea, tells us that in one instance where he was present, the inkstand upon the captain’s table was jerked upward against the ceiling, where it left an unmistakable record of the occurrence; and yet this vessel was steaming along in smooth water, many hundreds of fathoms deep. “The concussions,” he says, “were so smart that passengers were shaken off their seats, and, of course, thought that the vessel had run ashore.” All this disturbance was, nevertheless, only the result of a shock at the bottom; and when the non-elastic nature of water is considered, the severity of the jar is not surprising. It would seem as though in the vast breadth of the “world of waters,” and with nothing to obstruct the view, two ships might easily give one another a wide berth; yet a collision is one of the ever-present dangers of voyaging, even far from land. It is to avoid this peril that all the maritime nations have agreed upon certain signals, and “rules of the road” which are the same in all parts of the world, and without which it would now be almost impossible to carry on commerce or travel on the water. The rules of the road say that when two vessels are approaching one another, head on, each shall turn off to the right far enough to avoid the other; that when two vessels are crossing one another’s courses, the one which has the other on her starboard (right hand) must turn to starboard (the right), and go behind the other vessel, while the latter continues along her course; and that a steam vessel must always get out of the way of a sailing vessel, one at anchor or disabled, or a vessel with another in tow. It is presumed that every ship will keep a sharp lookout, and that in the daytime two approaching ships will see each other in time to keep safely apart; but in the darkness of night none could be safe unless all carried lights by which the position and character of each could be determined.