And yet he has been a very long time indeed finding the means of rising superior to the forces of Nature. He has had to fight very hard against heavy odds, he has had to devise no end of ingenious methods, most of which have been utterly useless, and many a man, overjoyed at his discovery of a sure means of overcoming the problem of propelling craft without sails or oars, has found at the last that in practice it was unworkable or too costly. Some have died from sheer want through sacrificing their all to this one end; others, rendered more sensitive by the ridicule and scorn of their fellow-men, have, on witnessing their own failure, died of a broken heart, and been reckoned by the least discerning as among those who wasted their lives in pursuing a shadow, frittered their time and money in seeking to attain the unattainable, and left behind them no monument except a pile of unworkable propositions and theories. But no generation is at any time of its career independent. From its first moments it is under a debt to those which have come and gone. Literature is but a collection of data amassed by our predecessors and handed down to the next age, which adds a little more to what is already known. It is scarcely possible to point to one man and say that he alone was the inventor of any new theory or device, although in carelessness we actually so speak. His own conclusions have been based on the accumulation of what his predecessors have left for him; and it is the same with the invention of the steamship. Some writers of different nationalities have patriotically upheld one man or another as the father of the steamship with a zeal that does more credit to their national loyalty than to their sense of historical fairness. In point of fact, although in different epochs one man has been more successful in practical experiment than another, we cannot, at any rate in the history of the steamship, give to that man a place of honour to the exclusion of all those who have gone before. Without their help he would never have succeeded. Their failures, even if they left him little to work on, at least showed him what to avoid. As an example we might here cite the instance of using a propeller shaped after the manner of a duck’s foot, which, being a close copy of the method employed by a species of animal which has its being on the surface of the water, appealed powerfully to more than one inventor as the likely way to solve a great problem; just as the early days of aviation were wasted in endeavouring to follow too closely the methods of locomotion adopted by birds. The years of man are but threescore and ten, and he cannot go on wasting his allotted time in trying and discarding all the experiments possible; but from the disordered mass of accumulated data he can extract just those which have any semblance of sound sense and practicability, from which he can deduce his own new theory and put it to actual test.