out, was pronounced an abandonment of his invention, because it was not a use for experiment or in private, but a practical use of the completed article. Even a single sale to a buyer, who bought the thing only "on trial," has been pronounced an abandonment.
A case of some hardship was that of a card-manufacturer who ran machines of his invention for several years under arrangements in-' tended to secure secrecy: a limited number of workmen were employed; the factory-doors were kept locked, each workman having a key; and visitors were but rarely admitted. Yet no formal pledge of secrecy was exacted from those who saw the machine. In course of time the inventor obtained a patent, but in the mean time his foreman had "given away" the secret to competitors. The Judge said that an inventor's conducting his business so that the public have an opportunity of knowing and imitating his invention forfeits his right, without proof that any great number of persons knew it. If any one knew it under such circumstances that he might have made it public without a breach of confidence, the right is abandoned.
With respect to delay, while it is familiar that an inventor is not limited to any particular time within which he must apply, yet the Supreme Court has lately said, quite emphatically, that, unless he is vigilant and active in applying, or there is good excuse, such as sickness, poverty, etc., for his postponement, he runs the risk that his invention will be considered abandoned to the public. The story of the case was, that Woodbury, in 1848, applied for a patent for an improvement in planing-machines, but it was rejected. He took no further steps until 1870, and meantime the principle of his invention had been adopted by other persons. Then he obtained a patent; but it was annulled for his long neglect. Inventors should be wary of disclosure and delay.
A decision of the Supreme Court known as Mitchell vs. Tilghman (19 Wall., 287) has given some persons an idea that a process can not be the subject of a patent; though the intention was, only to decide that the patentee was confined in his right to the particular method pointed out in his specification. He litigated the case further, gathered additional evidence, and presented the question to the Court again; and the Court has in effect overruled its former decision, now explaining emphatically that a patent may be, under American law, granted for a process. Our patent law is not confined to new machines and new compositions of matter, but extends to any new and useful art of manufacture; and a manufacturing process is clearly an art. The principle is that, whoever discovers that a certain useful result will be produced in any art by the use of certain means, is entitled to a patent, provided he fully and accurately specifies the means. This means need not be a machine or an apparatus; it may be a process. A machine is a thing. A process is a mode of action. The one is visible to the eye—an object of perpetual observation. The other is a