built by him in 1865. The identical machine, to be sure, is not directly in evidence; but castings are produced which were made from the same patterns as those used in the construction of that machine. The proof is clear that in that year he had given embodiment to the idea of rotating the arms upon their axis, in order to enable them to perform, at the will of the operator, the double function of rake and reel; and his subsequent diligence in perfecting the minor details of his aggregate mechanism fairly entitles him to refer to that year as the date of the inven tion of this particular feature.

Johnston, on the other hand, has preserved no draft nor fragment of the only machine he professes to have made, and after the time when the alleged trial of that machine took place he did nothing further toward developing or perfecting the invention for the space of three years. Then he simply constructed a rude model, and the making of this is succeeded by another period of delay of nearly a year and a half. During these delays another independent inventor reduces the invention to practice, and proceeds with due diligence to give the knowledge of it to the public through the medium of the Patent Office.

Johnston undertakes to explain and excuse his delay by calling attention to the fact that during that period he was forced to depend for his support upon his own labor, and that the salary received from his employers was small-evidently intending the inference to be drawn that he was pecuniarily unable to take early action in the premises. In his testimony, however, reference is made to transactions with certain other parties known in connection with harvester inventions as men of capital and business sagacity. An examination of the assignment records of the Patent Office shows more fully the character of these transactions, and from this source it appears that in 1865 he gave to a wellknown manufacturer full control over the management of this and other inventions and of any patent that might be issued upon them; and other transactions with Hubbard and with other parties, in that and the following year, indicate clearly enough that it could have been no lack of opportunity that deterred him from making an earlier application.

The delay must have been either because the invention was not regarded as reduced to practice or because of inexcusable negligence. Certain it is that after his first experiment he failed to use "reasonable diligence in perfecting and adapting" the invention; and because of this negligence, and the fact that the machine first made was laid aside, and at last disappeared so that all traces of it are lost, he cannot now be permitted to avail himself of that earlier experiment, to the prejudice of a subsequent diligent inventor. The doctrine laid down in Monce vs. Adams, Pat. Off. Gaz., vol. 1, No. 1, which holds an inventor to as strict accountability, within the measure of his means, for diligence in giving the knowledge of an invention to the public after he has perfected it as in reducing it to practice after its original conception, applies with equal if not greater force in the present case.

In Gayler vs. Wilder, 10 Howard, 477, the Supreme Court say that by the prior knowledge and use which would defeat the right of a subsequent original inventor to a patent, the legislature meant "knowledge and use existing in a manner accessible to the public;" and upon this ground refused to set aside the ruling of the court below, which virtually sustained the Fitzgerald patent notwithstanding the fact that a safe alleged to be like that covered by the patent had been actually made and used by Conner several years before the invention of Fitzgerald. The fact that the safe was not so used as to give the public a knowledge of the mode of its construction, and that at last it passed into other hands and was lost to view, left the public, according to the course of reasoning adopted by the court, in the same situation as if the improvement had never been discovered; so that, in carrying out the real intent of the law, protection would justly belong to such other person as at that time should come forward, and by an effort of his own genius confer upon the community the benefit of the invention,

This decision proceeded upon the supposition that Conner's discovery Lad been finally forgotton or abandoned without any knowledge of it passing to the public. In the present case it can hardly be supposed that Johnston had wholly forgotten about his alleged invention of 1863; but his negligence seems to have been such as, under the precedents established in the cases of Monce vs. Adams, above referred to, and Gray vs. Hale, C. D., 1871, p. 129, to charge him with forfeiture, even though there may have been no definite intention on his part to abandon the invention. It is true that this case differs from that adjudicated in Gayler vs. Wilder in the circumstance that here the invention was taken up after a lapse of years by the same party who originally discovered it. This, however, must be looked upon as an immaterial fact when viewed in the light of the further circumstance that meanwhile this inventor had shown himself guilty of such negligent postponement of his claims as would entitle another independent inventor to come in and secure a patent. The main essential fact is, that while this alleged inventor was concealing his discovery from the public eye, and for a period of years was doing nothing toward developing and perfecting it, another person, proceeding by an entirely independent course, originates the same invention, perfects it by a series of practically-continuous experiments, and proceeds without delay to make the knowledge of it public through the medium of an application filed in the Patent Office. It is believed that this fundamental fact brings the case fully within the spirit of the decision in Gayler vs. Wilder; and accordingly priority of invention is awarded to Kirby.

P. V. MATHEWS.

Extension.

APPLICATION FOR THE EXTENSION OF LETTERS PATENT FOR A MODE OF PROTECTING GILDING ON GLASS, GRANTED TO P. V. MATHEWS APRIL 27, 1858.

(Decided April 23, 1872.)

Ascertained value of an invention.

The naked allegation of an applicant for the extension of a patent, that the invention is "exceedingly useful," when he has the means of furnishing data by which the Office can form a judgment as to the correctness of his averment, but withholds the same, is not a compliance with the requirement of the law calling for a "written statement under oath of the ascertained value of the invention."

DUNCAN, Acting Commissioner :

In this case the patentee has filed no testimony in support of the various allegations contained in his petition and in his "statement of account." From the latter we learn that he has sold territorial and shop rights under his patent to the amount of nineteen hundred and sixty dollars; but he brings forward none of the various assignees and licensees to enlighten the Office as to the practical working of the invention. It would have been an easy matter to do this, and in this way we might have learned the "ascertained value" of the invention. As it is, the Office is furnished with no information upon this point beyond the naked allegation of the patentee that the invention is "exceedingly useful.”

This is not a compliance with the requirement of the law that the applicant must furnish "a written statement under oath of the ascertained value of the invention;" or, if it be a technical compliance with it, it fails inasmuch as there is a withholding of data in the possession of the applicant by which the Office might form a judgment as to the correctness of his averment regarding the importance of the invention. This is regarded as a fatal defect in the presentation of the case, and the extension is accordingly refused.

W. S. COTTRELL.-EX PARTE.

APPLICATION FOR LETTERS PATENT FOR ZINC-BOARD-APPEAL FROM THE EXAMINERS-IN-CHIEF.

(Decided April 29, 1872.)

New articles of manufacture as created by the substitution of material.

Where, by the substitution of tar-board or paste-board for wood, in combination with a zinc covering, for the protection of floors and other surfaces from the injurious effects of radiated heat, a convenient article of commerce was produced that supplied a recognized want in the community, while the wood and the zinc, on account of the greater thickness necessarily required in the wood to prevent it from warping, had never been combined except by the user: Held, that this was not a mere substitution of material, but was the creation of a new article of manufacture, for which a patent should be allowed.

DUNCAN, Acting Commissioner :

Applicant's alleged invention consists in covering tar-board or paperboard with zinc, and thus forming a convenient article of manufacture to be put upon the market and used to protect floors, carpets, and other surfaces about a stove from the injurious effects of the radiated heat.

The application is rejected upon reference to the well-known fact, adverted to in the specification, that wood with a zinc covering has been used for a similar purpose, and it is held in the majority opinion of the Examiners-in-Chief that this fact constitutes the use of the tar-board a mere substitution of material.

Applicant, on the other hand, insists that wood and zinc as thus used had never before been combined except by the consumer; that the thickness of wood required to prevent warping was necessarily so great that these two materials could not well be combined to form an article of manufacture to be put upon the market for sale in its completed form; that he is the first to make a "zinc-board," which, as an attractive article of merchandise, supplies a recognized want in the community, and that he has been enabled to do this by substituting for the wood previously used a substance which, while equally non-conducting, can be used in thin sheets without warping. He thus professes to have pro. duced a new article of manufacture, and upon this theory he urges that he is entitled to a patent.

I think that this view of the case is the correct one. He has not simply suggested to the consumer a substitute for the wood previously used; he has created a new vendible article which answers a public want. The decision of the Examiners-in-Chief is overruled.

LEWIS MILLER.

Extension.

IN THE MATTER OF THE APPLICATION FOR THE EXTENSION OF THE REISSUES OF LEWIS MILLER'S HARVESTER PATENTS OF MAY 4, 1858. (Decided April 30, 1872.)

The novelty of the invention at the time of the grant.—The mode of estimating profits for the "statement of account."

A finger-beam which folds over to a horizontal position and lies flat upon the main frame, so as to throw its weight when folded upon both wheels of the carriage and require no locking device to hold it in position when moving from place to place, is not anticipated by a finger-beam which is made to stand in a nearly vertical position, requiring a locking device to hold it in position when moving to and from its work, and which throws the greater portion of the weight of the beam on one wheel.

Such an improvement may involve but little change in form; but a change in form and proportions, if a new and useful result be secured, may be patentable, depending, of course, upon whether such changes call for inventive genius or merely mechanical skill.

A flexible brace having one end attached to the coupling-arm, in front of the carriageaxle and near the hinge of the finger-beam, the other end being hinged to the main frame in the rear of the axle, is not anticipated by a stiff brace, differently situated, inflexible, and not connected with any coupling-arm, hinged or otherwise.

A lever and cord having been used to raise the end of a coupling-arm to elevate the finger-beam over an obstruction, a claim should not have been allowed for the use of the lever and cord as an adjunct in the operation of folding the finger-beam. The purpose of a party in raising the beam has no bearing upon the question.

The substitution for one lever of another having a different but not novel construction, the purpose, mode of operation, and result remaining unchanged by the transfer, is not patentable.

A claim to a locking device attached to a lever, in combination with a coupling-arm and finger-beam, can hardly be considered legitimate, as the locking device had previously been used for the same purpose, and its operation is not affected by the peculiarities of construction or working of the coupling-arm or finger-beam.

A claim to placing the "lead-wheel" in the front part of the inner shoe is not met by the citation of a "lead-wheel” attached to the coupling-arm near its lower hinge, leaving a space between it and the shoe.

Where a patentee has granted permission to others to make his patented device for a specified royalty, and where any considerable number have been thus manufactured, such royalty becomes the fairest and simplest measure of profits; but where a patentee has made a close monopoly of his patent, the Office will demand a statement from him of his profits as a manufacturer.

Where a patentee has sold four-fifths of his patent and only returned the profits on the remaining fifth: Held, that he may, as the testimony indicates, have received larger returns from the fifth which remained to him, after sacrificing four-fifths to obtain means to test and develop his invention, than he would probably have obtained by retaining the whole in his own hands. In such a case the statement of his profits, based on the proceeds of the fifth, is the only just one that can be adopted.