improvement of such machinery only. Story J. said, "That it would not protect the plaintiff's patent, that he was the inventor of all the material improvements in the old machine, (as is asserted) if he suffered them to be used freely and fully by the public at large for so many years, combined with all the usual machinery; for in such a case I think he must be deemed to have made a gift of them to the public, as much as a person who voluntarily opens his land as a highway, and suffers it to remain for a length of time devoted to public use."'145

In the other case the same judge said, "If the inventor dedicates his invention to the public, he cannot afterwards resume it, or claim an exclusive right in it. It is like the dedication of a public way or other public easement. The question in such cases is a question of fact-Has he so dedicated it? I agree his acts are to be construed liberally; that he is not to be stopped by licensing a few persons to use his invention to ascertain its utility, or by any acts of such peculiar indulgence and use, as may fairly consist with the clear intention to hold the exclusive privilege. But if the inventor proclaims his invention to all the world, and suffers it to go into general and public use without objection; if he asserts no exclusive right for years, with a full knowledge, that the public are led by it to a general use,

145 Whittemore v. Cutter, 1 Gallison, 482.

such conduct amounts to strong proof, that he waives the exclusive right and dedicates the invention to the world. After such conduct, the attempt to regain the exclusive right and secure it by a patent, would operate as a fraud upon the public; and would hold out inducements to incur heavy expenses in putting inventions into operation, of which the party might be deprived at the mere will or caprice of the inventor.'

66

??146

Mr. Justice M'Lean, giving the opinion of the Supreme Court of the United States upon this subject, said, Vigilance is necessary to entitle an individual to the privilege secured under the patent law. It is not enough that he should show his right by invention, but he must secure it in a mode required by law. And if the invention, through fraudulent means, shall be made known to the public, he should assert his right immediately, and take the necessary steps to legalize it. The patent law was designed for the public benefit, as well as for the benefit of inventors. For a valuable invention, the public, on his complying with certain conditions, give him, for a limited period, the profits arising on the sale of the thing invented. This holds out an inducement for the exercise of genius and skill in making discoveries which may be useful to society, and profitable to the discoverer. But it was not the intention of this law,

146 Mellus v. Silsbee, 4 Mason, 108.

to take from the public that of which they were fairly in possession. In the progress of society, the range of discoveries in the mechanic arts, in science, and in all things which promote the public convenience, as a matter of course, will be enlarged. This results from the aggregation of mind, and the diversity of talents and pursuits, which exist in every intelligent community. And it would be extremely impolitic to retard or embarrass this advance, by withdrawing from the public any useful invention or art, and making it a subject of private monopoly. Against this consequence, the legislature have carefully guarded, in the laws they have passed on the subject. It is, undoubtedly, just that every discoverer should realize the benefits resulting from his discovery, for the period contemplated by law. But these can only be secured by a substantial compliance with every legal requisite. His legal right does not rest alone upon this discovery; but also upon the legal sanctions which have been given to it, and the forms of law with which it has been clothed. No matter by what means an invention may have been communicated to the public before a patent is obtained; any acquiescence in the public use, by the inventor, will be an abandonment of his right. If the right were asserted by him who fraudulently obtained it, perhaps no lapse of time could give it validity. But the public stand in an entirely different relation to the inventor. The invention passes into the possession of innocent

persons, who have no knowledge of the fraud, and at a considerable expense, perhaps, they appropriate it to their own use. The inventor or his agent has full knowledge of these facts, but fails to assert his right; shall he afterwards be permitted to assert it with effect? Is not this such evidence of acquiescence in the public use, on his part, as justly forfeits his right? If an individual witness the sale and transfer of real estate, under certain circumstances, in which he has an equitable lien or interest, and does not make known this interest, he shall not afterwards be permitted to assert it. On this principle it is, that a discoverer abandons his right, if, before the obtainment of his patent, his discovery goes into public use. His right would be secured by giving public notice that he was the inventor of the thing used, and that he should apply for a patent. Does this impose any thing more than reasonable diligence on the inventor? And would any thing short of this be just to the public? The acquiescence of the inventor in the public use can, in no case, be presumed, when he has no knowledge of such use. But this knowledge may be presumed from the circumstances of the case. This will, in general, be a fact for the jury. And if the inventor do not, immediately after this notice, assert his right, it is such evidence of acquiescence in the public use, as for ever afterwards to prevent him from asserting it. After his right shall be perfected by a patent, no presumption

arises against it from a subsequent use by the public. When an inventor applies to the Department of State for a patent, he should state the facts truly; and indeed he is required to do so under the solemn obligations of an oath. If his invention has been carried into public use by hand; but for a series of months or years he has taken no steps to assert his right, would not this afford such evidence of acquiescence as to defeat his application as effectually as if he failed to state that he was the original inventor? And the same evidence which should defeat his application for a patent, would, at any subsequent period be fatal to his right. The evidence he exhibits to the Department of State is not only ex parte, but interested; and the questions of fact are left open to be controverted by any one, who shall think proper to contest the right under the patent. The strict construction of the act, as it regards the public use of an invention, before it is patented, is not only required by its letter and spirit, but also by sound policy. A term of fourteen years was deemed sufficient for the enjoyment of an exclusive right of an invention by the inventor, but if he may delay an application for his patent, at pleasure, although his invention be carried into public use, he may extend the period beyond what the law intended to give him. A pretence of fraud would afford no adequate security to the public in this respect, as artifice might be used to cover the transaction. The doctrine of pre