George Stephenson had now been diligently employed for several years in the work of self-improvement, and he experienced the usual results in increasing mental strength, capability, and skill. Perhaps the secret of every man's best success in life is to be found in the alacrity and industry with which he takes advantage of the opportunities which present themselves for well-doing. Our engine-man was an eminent illustration of the importance of cultivating this habit of life. Every spare moment was laid under contribution by him, either for the purpose of adding to his earnings or to his knowledge. He missed no opportunity of extending his observations, especially in his own department of work, aiming at improvement, and trying to turn all that he did know to useful practical account. He continued his attempts to solve the mystery of Perpetual Motion, and contrived several model machines with the object of embodying his ideas in a practical working shape. He afterward used to lament the time he had lost in these futile efforts, and said that if he had enjoyed the opportunities which most young men now have, of learning from books what previous experimenters had accomplished, he would have been spared much labor and mortification. Not being acquainted with what other mechanics had done, he groped his way in pursuit of some idea originated by his own independent thinking and observation, and, when he had brought it into some definite form, lo! he found that his supposed invention had long been known and recorded in scientific books. Often he thought he had hit upon discoveries which he subsequently found were but old and exploded fallacies. Yet his very struggle to overcome the difficulties which lay in his way was of itself an education of the best sort. By wrestling with them, he strengthened his judgment and sharpened his skill, stimulating and cultivating his inventiveness and mechanical ingenuity. Being very much in earnest, he was compelled to consider the subject of his special inquiry in all its relations, and thus he gradually acquired practical ability through his very efforts after the impracticable.