used practically, will not defeat the novelty of the later patent. Swift v. Whisen, 3 Fish. 343; s. c. 2 Bond 115.

If it appears that the alleged prior invention or discovery was only an experiment, and was never perfected or brought into actual use, but was abandoned and never revived by the alleged inventor, the mere fact of having unsuccessfully applied for a patent therefor can not take the case out of the category of unsuccessful experiments. Brown v. Guild, 23 Wall. 181; s. c. 6 O. G. 392; 7 O. G. 739; Union P. B. M. Co. v. P. & W. Co., 15 O. G. 423; s. c. 15 Blatch. 160; s. c. 3 Ban & Ard. 403.

The devices contained in an abandoned experiment can not be used to defeat the patent of an independent and successful inventor. Aultman v. Holley, 6 Fish. 534; s. c. 11 Blatch. 317; 5 O. G. 3.

If a process is practiced once as an experiment, and then abandoned, this mere experiment will not be an obstacle to the right of a subsequent inventor. Brown v. Piper, 4 Fish. 175; s. c. 1 Holmes 20; 91 U. S. 37; s. c. 10 0. G. 417.

The fact that the alleged prior machine was not actually put into practical use affords grounds for presuming that it was a mere experiment. Cahoon v. Ring, 1 Fish. 397; s. c. 1 Cliff. 592.

The desertion of an invention consisting of a machine never patented may be proved by showing that the inventor, after he had constructed it, and before he had reduced it to practice, broke it up as something requir ing more thought and experiment, and laid the parts aside as incomplete, provided it appears that those acts were done without any definite intention of resuming his experiments and of restoring the machine. Seymour v. Osborne, 11 Wall. 516; s. c. 3 Fish. 555.

If the inventor produced a complete invention, but was repulsed by the patent office, and abandoned further efforts to secure the full benefit of the invention to himself and the public, such abandonment does not reduce his matured invention to the grade of a mere experiment. Northwestern Co. v. Philadelphia Co., 6 O. G. 34; s. c. 1 Ban & Ard. 177.

If the disuse of a machine for a time was due to circumstances connected with the demand and supply of the product and independent of the efficiency of the mechanism, it can not be deemed an abandoned experiment. Snow v. Tapley, 13 O. G. 548; s. c. 3 Ban & Ard, 228.

Use of Invention.

If the prior machine is perfect and capable of use, it is not necessary that it should be actually used, but it must have been capable of such Parker v. Ferguson, 1 Blatch. 407; Pitts v. Wemple, 2 Fish. 10; s. c. 1 Biss. 87.

use.

It is not necessary that the prior inventor shall have worked the process with the same degree of skill and success as the patentee attains. It is sufficient if he did it with a degree of success which demonstrated its usefulness. Waterman v. Thomson, 2 Fish. 461; Pitts v. Wemple, 2 Fish. 10; s. c. 1 Biss. 87.

The mere fact that the prior inventor ceased to use his machine, because he had no occasion to do so, is of itself of no importance. Waterman v. Thomson, 2 Fish. 461.

If the invention was successful, and no change of mechanism was needed, its use may be altogether discontinued; but this will not give a subsequent inventor the right to take it up and appropriate it exclusively. Shoup v. Henrici, 9 O. G. 1162; s. c. 2 Ban & Ard. 249.

Diligence in Perfecting Invention.

He who invents first has the prior right if he uses reasonable diligence in adapting and perfecting his invention. White v. Allen, 2 Fish. 440; s. c. 2 Cliff. 224; Reed v. Cutter, 1 Story 590; s. c. 2 Robb 81; Singer v. Walmsley, 1 Fish. 558; Kneeland v. Sheriff, 18 O. G. 242; s. c. 5 Ban & Ard. 482; s. c. 2 Fed. Rep. 901; Electric R. S. Co. v. Hall R. S. Co., 6 Fed. Rep. 603.

It is the right and privilege of a party, when an idea enters his mind in the essential form of invention, to perfect by experiment and reasonable diligence his original idea, so as not to be deprived of the fruit of his skill and labor by a prior patent, if he is the first inventor; but there must be a reasonable diligence looking to all the facts of the case. Griggs, 2 Fish. 174; s. c. 1 Biss. 362; Winans v. Schen. & Troy R. R. Co., 2 Blatch. 279; Whitney v. Emmett, Bald. 303; s. c. 1 Robb 567; National Oil Co. v. Arctic Oil Co., 4 Fish. 514; s. c. 8 Blatch. 416.

Cox v.

If two inventors conceive the invention at about the same time, the one who first reduces it to practice is the first inventor. Seibert C. O. C. Co. v. Phillips L. Co., 10 Fed. Rep. 677.

If two parties are jointly experimenting and equally meritorious, a doubt should be solved in favor of him who first obtains a patent. Cox v. Griggs, 2 Fish. 174; s. c. 1 Biss. 362.

The relation borne to the public by inventors, and the obligations they are bound to fulfil in order to secure for the former protection and the right to remuneration, by no means forbid a delay requisite for completing an invention, or for a test of its value or success by a series of sufficient and practical experiments; nor do they forbid a discreet and reasonable forbearance to proclaim the theory or operation of a discovery during its progress to completion and preceding an application for protection in that discovery. Kendall v. Winsor, 21 How. 322.

No delay in taking out a patent is fatal to the earliest or first inventor, unless he abandons his discovery to the public, or by his consent allows it to be put in public use or on sale for two years before taking out a patent. If there has been no such abandonment or public use, the earliest invention will prevail over a succeeding one, though the latter may be made and used before letters patent are taken out for the first. Allen v. Blunt, 2 W. & M. 121; s. c. 2 Robb 530; Hildreth v. Heath, Cranch Pat. Dec. 96.

If the patentee was induced to believe that his invention had been

anticipated, and decided to keep it a secret and practice it for his own benefit, but applied for a patent as soon as he discovered his mistake, he did use reasonable diligence. Ayling v. Hull, 2 Cliff. 494.

If the inventor, after he has perfected his invention, unreasonably delays his application for a patent, and other persons before such application is made actually perfect and apply the same invention to practical use, and give the knowledge thereof to the public, and the first inventor, after the knowledge of such subsequent invention or discovery, and its public use, fails to make objection and to apply without unreasonable delay for a patent for his invention, he can not sustain his patent, because he failed to give to the public that consideration for the grant of exclusive privileges upon which all valid patents must be based. New York v. Ransom, 23 How. 487; s. c. 1 Fish. 252.

If an inventor has not used reasonable diligence in perfecting and adapting his invention, he will not be protected against a subsequent inventor, although he had previously conceived the idea of the invention, and sketched it on paper. Reeves v. Keystone Bridge Co., 5 Fish. 456;

s. c. 9 Phila. 368; 1 O. G. 466; 5 A. L. T. 150; Carlton v. Atwood, 2 A. L. T. R. 129; Kirby v. Johnson, 1 O. G. 405; Gates v. Benson, 3 A. L. T. (U. S.) 113; Agawam Co. v. Jordan, 7 Wall. 583; Electric R. S. Co. v. Hall R. S. Co., 6 Fed. Rep. 603; Detroit L. Manuf. Co. v. Renchard, 9 Fed. Rep. 293.

If the inventor used reasonable diligence in perfecting and adapting his invention he may show the inceptive invention by sketches and drawings, and the protection of the patent will be carried back to that date. Draper v. Potomska Mills Corporation, 13 O. G. 276; s. c. 3 Ban & Ard. 214.

Effect of Concealment.

If the first inventor makes the discovery in his closet, and confines the knowledge to himself, such knowledge will not invalidate a subsequent patent to another. Whitney v. Emmett, Bald. 303; s. c. 1 Robb 567; Rowley v. Mason, 2 A. L. T. (U. S.) 106; Judson v. Bradford, 16 O. G. 171; s. c. 3 Ban & Ard. 539.

It would be strange, indeed, if, because the first inventor would not permit other persons to know his invention, or to use it, he should thereby be deprived of his right to obtain a patent, and it should devolve upon a subsequent inventor, merely from his ignorance of any prior invention or prior use, or that a subsequent inventor should be entitled to a patent, notwithstanding a prior knowledge or use of the invention by one person, and yet should be deprived of it by a like knowledge or use of it by two persons. Reed v. Cutter, 1 Story 590; s. c. 2 Robb 81.

If the alleged first inventor did not make his discovery public, but used it simply for his own private purpose, and it was finally forgotten or abandoned, such discovery and use will not defeat the rights of a subsequent inventor, if he is an original, though not the first inventor. Gayler v. Wilder, 10 How, 477; Hall v. Bird, 3 Fish. 595; s. c. 6 Blatch. 438; Bullock P. P. Co. v. Jones, 13 O. G. 124; s. c. 3 Ban & Ard. 195.

If only a single specimen of the alleged prior machine was made, whether capable of use, and whether actually used or not by the party making it for the purpose of testing its operation, it will not invalidate a patent by a subsequent inventor, if it was kept in the possession of the maker from the knowledge of the public, and subsequently broken up, and the essential parts of it did not exist at the time of the subsequent invention, so that the public could derive the knowledge of it from the machine itself, but merely from the memory of the maker. Cahoon v. Ring, 1 Fish. 397; s. c. 1 Cliff. 592; Sayles v. Railroad Company, 2 Fish. 523; s. c. 1 Biss. 468; Stainthorp v. Humiston, 4 Fish. 107; Piper v. Brown, 4 Fish. 175.

An inventor who withholds his invention from the public designedly, and with the view of applying it indefinitely and exclusively for his own profit, does not come within the objects or policy of the Constitution or acts of Congress. He does not promote, and if aided in his design would impede, the progress of science and the useful arts. Hence if, during such a concealment, an invention similar to or identical with his own, should be made and patented, or brought into use without a patent, the latter could not be inhibited or restricted, upon proof of its identity with a machine previously invented and withheld or concealed by the inventor from the public. Kendall v. Winsor, 21 How. 322.

If there has been, at any time, and under any circumstances, an accidental discovery similar in character to that which the patentee has patented, but the public obtained no knowledge of the invention, then the invention was not produced by the party who made such discovery. In other words, if the party did not comprehend the invention, he added nothing to his own stock of knowledge, and the fact, if observed by other men, added nothing to the knowledge of science upon that subject. Therefore, the invention was not made until the party contriving, or others observing, the invention, saw that it could be made available for the purpose of producing a result similar to the one which the patentee mentions in his specification. New York v. Ransom, 23 How. 487; s. c. 1 Fish. 252. It is well known that centuries ago discoveries were made in certain arts, the fruits of which have come down, but the means by which the work was accomplished are at this day unknown; the knowledge has been lost for ages; yet, if any one now were to discover an art thus lost, and it were a useful improvement, he would be entitled to a patent. Yet he would not literally be the first and original inventor, but he would be the first to confer on the public the benefit of the invention. He would discover what is unknown, and communicate knowledge which the public had not the means of obtaining without his invention. Gayler v. Wilder, 10 How. 477.

Utility.

An invention is not useful which will not enable the operator to accomplish the desired result. Mitchell v. Tilghman, 4 Fish. 599; s. c. 19 Wall. 287; 5 O. G. 299; s. c. 9 Blatch. 1; s. c. 2 Fish. 518; Hubbell v. U. S., 5 Ct. Cl. 1; Royer v. Russell, 20 O. G. 1819; s. c. 9 Fed. Rep. 696.

It is not sufficient that the invention is useful for some purpose. If it is impracticable to be used for the purpose for which it was patented, the patent is void. Rowe v. Blanchard, 18 Wis. 441.

If no person can make use of the invention advantageously, the patent is void. Dickinson v. Hall, 31 Mass. 217; Ross v. Wolfinger, 5 O. G. 117 ; Bliss v. Brooklyn, 6 Fish. 289; s. c. 10 Blatch. 521; 3 O. G. 269.

The law does not look to the degree of utility. It simply requires that the invention shall be capable of use, and that the use be such as sound morals and policy do not discountenance. Bedford v. Hunt, 1 Mason 302; s. c. 1 Robb 148; Dunbar v. Marden, 13 N. H. 311.

The invention must be useful to an appreciable extent, although the measure of that usefulness is not material. Any degree of utility appreciable by a jury is sufficient. Conover v. Roach, 4 Fish. 12.

The court will not be very rigid as to the degree of utility. It will not inquire into the precise quantum of value, but if the invention is useful in any degree, and not absolutely worthless, the patent will be sustained. Vance v. Campbell, 1 Fish. 483; s. c. 1 Black 427; Tilghman v. Werk, 2 Fish. 229; s. c. 1 Bond 511; Ex parte Geo. Richardson, 2 O. G. 3.

The question is not whether the invention is useful beyond all other machines in use for effecting the object for which it was designed, but whether it is capable in some degree of beneficial use, or will in some degree subserve the purpose of its design, or whether, on the contrary, it is merely mischievous and injurious, or pernicious, or frivolous and worthless. Dunbar v. Marden, 13 N. H. 311; Crouch v. Speer, 6 O. G. 187; s. c. 1 Ban & Ard. 145.

If the invention is useful, it is not necessary that the thing patented should be the best possible thing of the kind that could be made. Winans v. Schen. & Troy R. R. Co., 2 Blatch. 279; Wilbur v. Beecher, 2 Blatch. 132; Crompton v. Belknap Mills, 3 Fish. 536.

The law does not require the patentee to prove his discovery to be useful to an eminent or large degree. It is sufficient if it produces an improved article at less cost or with more expedition than other known methods. Carr v. Rice, 1 Fish. 198.

The question is not whether the patented machine does its work better or faster than any other machine in the same department of labor. If it is to a certain degree useful and is original with the patentee, it belongs to him alone, whether it does less or more work. Wilbur v. Beecher, 2 Blatch. 132.

To what extent an invention must be useful to render it the subject of a patent, will depend on the particular circumstances of each case, and for which no general rule can be given, but it must, in some small measure at least, be beneficial to the community. This utility is to be tested not merely by the benefits which the patentee may obtain, but by the advantages which the public are to derive from it. Langdon v. De Groot, 1 Paine 203; s. c. 1 Robb 423.

The

It is not necessary that the invention should be of general utility. word useful is incorporated into the statute in contradistinction to mis