"But the most probable cause of unexplained losses of ships at sea is fire, or it is one, at least, which divides probabilities with explosions and icebergs. Even on the supposition of an explosion, it seems almost inexplicable that no trace of a sunken vessel should ever afterwards be seen. A missing liner or other large vessel is a source of interest to all seafaring men, and a keen outlook is kept on the track which the vessel was known to have taken. Any stray spar or belt or bit of wreckage, therefore, could scarcely escape observation. If a vessel sinks in mid-ocean some portions float. But if a vessel is burned everything would probably be consumed, as the vessel would burn to the water's edge. Boats might or might not be launched, according to the rapidity of the rush of the flames, the state of the weather, etc. If boats are launched, say, a thousand miles from land, the chances of rescue or of making land are remote. Fire, therefore, seems adequate enough to account for the loss of some of the numerous vessels which have never been heard from after leaving port. "Considering other possible external causes of the total disappearance of liners, heavy weather must be regarded as a probable reason in some instances. Although we do not admit that the roughest weather would harm a modern liner, we must remember that the older vessels were not as large and powerful as those of the present time. The _Pacific_, for example, which disappeared in 1856, was not nearly half the length of the latest vessels. Bulkheads had not been brought to the perfect condition of security which they have now attained. Not infrequently even now steamers become water-logged and reach a sinking condition and their crews are happy if rescued. It may well have happened that vessels have foundered in mid-ocean in consequence of not being able to receive assistance, while the sailors could not take to their boats with any hope of living in the tempest. "Uncharted rocks also cause the loss of vessels, as in the case of the _Pericles_. But her captain was a man of resource and no lives were lost. "Icebergs are a probable cause for the loss of some vessels, especially of liners running to Canadian ports. The damage to the _Arizona_ may be instanced, and many other vessels have had hairbreadth escapes. A vessel insufficiently secured by bulkheads would stand a poor chance in collision with an iceberg.