One of the most unsatisfactory parts of an inventor's experience is the difficulty he has in making other men see the value of his inventions, combined with the fact that when the invention is finally adopted, his part in it is often forgotten, and sometimes intentionally ignored. This applies especially to inventions of a high order of originality, that are a little in advance of the requirements and knowledge of most men at the time, and that are looked upon as visionary and do not come into use for a considerable while. Many an inventor has endured a purgatory while trying to get a hearing for his invention, and yet been wholly forgotten when it was finally adopted. To make the matter worse, he has often been branded for life as a visionary, and remained so branded, even after the invention had been adopted because of which he had been branded. In other cases, manufacturers have stolen his invention and denied his claims, knowing that he was too poor to fight against them with all of their resources. In other cases, business men and lawyers have combined to induce him to sign papers of a highly advantageous character to the business men, but contrariwise to the inventor. In all of these cases, the matter has usually been the worse for the inventor in proportion to the high order of the invention: for the real inventor, like the real artist, is usually so absorbed in his thoughts that he cares but little (too little) for material gain. The case of the inventor who makes a business of inventing is somewhat different. He usually confines his efforts to making inventions that will bring in money, becomes an expert on nice points in patent law, discerns chances for circumventing existing patents while utilizing their basic principles, perceives opportunities for making the little improvements in detail that promote practicability, and becomes the kind of inventor who owns a limousine.