It is to no purpose to tell the Perpetual Motion worker that he is seeking to attain the impossible; that the attainment of self-motive power has been demonstrated to be an impossibility. He will answer, or, at least, he will reason to himself that many things once pronounced impossibilities and claimed to be so demonstrated, have since been attained. The Perpetual Motion worker is usually a person of active intelligence, and being enamoured of mechanical projects is likely to read extensively along mechanical lines, and knows as every well-informed person knows, that there are many instances in the history of the discovery and development of the most important mechanical inventions and scientific discoveries where the persistent efforts of so-called enthusiastic dreamers and cranks finally triumphed over the settled and conventional "impossibilities" of dignified scientists. When, less than a century ago, it was proposed to propel a ship across the Atlantic ocean by steampower, Ignatius Lardner, a scientific teacher, lecturer and interpreter of real note and merit wrote a book "demonstrating" the physical impossibility of a vessel carrying enough fuel to propel itself through that distance of water. The book was actually printed, but was scarcely off the press until the first steamship had successfully crossed the Atlantic with steampower, and steamed triumphantly into port. After communication by electric telegraph was well established and had been in successful commercial use for decades, it was proposed to converse by long distance over a wire. The idea was hooted and declared impossible, and it did seem so, and yet today, there is scarcely a farm house in the nation but what has an instrument by which the occupants can talk over wires not only to their near-by neighbors, but to remote cities.