Opinion of the Court. invention consists in attaching to the back portion of the boot or shoe in which a vertical slit or opening has been made a folding flap or piece of sufficient size and shape that, when the boot or shoe is put on the foot, it can be folded or passed entirely around the instep, and there fastened by buckling, buttoning, or in any other proper manner, said flap being connected therewith by means of two wings or sectional pieces, each fastened by sewing, or in or in any other suitable way, at one edge to one side of opening or slit in the boot or shoe and at the other to the inner surface of the folding flap, and which wings, when the folding flap has been buttoned, as described, lie and are held between it and the exterior surface of the boot or shoe upper." The advantages claimed for the Brown and Wooton patent were the ease with which the shoe could be put on and taken off, the absence of eyelet holes or any kind of apertures communicating with the interior of the shoe, and the peculiar construction and arrangement of the flap, whereby the counter of the shoe was prevented from being broken down. Such was the state of the art when Evory and Heston made their application for the patent in suit. Let us now carefully examine the Evory and Heston patent to see what patentable improvements are embraced by it. In the first part of the specification it would seem that they were seeking a patent for a mode of constructing a shoe, for they say: "Our said invention consists in a novel mode of constructing shoes and gaiters," etc. And in another part of their specification they say; "Our mode of construction is an improvement upon " the Babbit patent, etc. But the concluding part of their specification would seem to negative the idea that they were claiming a patent for a mode of construction, and not for a manufactured article; for they say; "What we do claim as our invention and desire to secure by letters patent is a shoe when constructed with an expansion-gore flap," etc. In the brief of counsel for appellees it is conceded that the patent is for a shoe, and not for a mode of constructing it. Counsel says, after quoting the concluding paragraph of the specification: "This is a claim for a shoe having on each side an expansion-gore flap,” etc. Opinion of the Court. We think, therefore, the claim in this case must be regarded as being for a manufactured article, and not for a mode of producing it. This being true, it is difficult to see any patentable device or function in the Evory and Heston shoe. It is a mere aggregation of old parts with only such changes of form or arrangement as a skilful mechanic could readily devisethe natural outgrowth of the development of mechanical skill as distinguished from invention. The changes made by Evory and Heston in the construction of a water-tight shoe were changes of degree only, and did not involve any new principle. Their shoe performed no new function. In the construction of it the vamp, the quarters and the expansible gore flap were cut somewhat differently, it is true, from like parts of the shoes constructed under the earlier patents referred to, but they subserved the same purposes. It is well settled that not every improvement in an article is patentable. The test is that the improvement must be the product of an original conception. Pearce v: Mulford, 102 U. S. 112, 118; Slawson v. Grand Street Railroad, 107 U. S. 649; Munson v. New York City, 124 U. S. 601, and many other cases. And a mere carrying forward or more extended application of an original idea-a mere improvement in degree is not invention. In Smith v. Nichols, 21 Wall. 112, 118, 119, Mr. Justice Strong, delivering the opinion of the court, said: "A patentable invention is a mental result. It must be new and shown to be of practical utility. Everything within the domain of the conception belongs to him who conceived it. The machine, process, or product is but its material reflex and embodiment. A new idea may be ingrafted upon an old invention, be distinct from the concep tion which preceded it, and be an improvement. In such case it is patentable. The prior patentee cannot use it without the consent of the improver, and the latter cannot use the original invention without the consent of the former. But a mere carrying forward or new or more extended application of the original thought, a change only in form, proportions or degree, the substitution of equivalents, doing substantially the same thing in the same way, by substantially the same means, Opinion of the Court. with better results, is not such invention as will sustain a patent. These rules apply alike, whether what preceded was covered by a patent or rested only in public knowledge and use. In neither case can there be an invasion of such domain and an appropriation of anything found there. In one case everything belongs to the prior patentee; in the other, to the public at large." Neither is it invention to combine old devices into a new article without producing any new mode of operation. Stimpson v. Woodman, 10 Wall. 117; Heald v. Rice, 104 U. S. 737; Hall v. Macneale, 107 U. S. 90. In the recent case of Hill v. Wooster, decided January 13 of this year, 132 U. S. 693, 700, it is said: "This court, however, has repeatedly held that, under the Constitution and the acts of Congress, a person, to be entitled to a patent, must have invented or discovered some new and useful art, machine, manufacture or composition of matter, or some new and useful improvement thereof, and that 'it is not enough that a thing shall be new, in the sense that in the shape or form in which it is produced it shall not have been before known, and that it shall be useful, but it must, under the Constitution and the statute, amount to an invention or discovery;"" citing a long list of authorities. We are of the opinion that the patent in suit does not meet the requirements of the rules deduced from the decisions to which we have referred. We do not think there is any patentable invention in it; but, on the contrary, that it is merely a carrying forward of the original idea of the earlier patents on the same subject — simply a change in form and arrangement of the constituent parts of the shoe, or an improvement in degree only. For these reasons the decree of the court below is reversed, with a direction to dismiss the bill. Opinion of the Court. PHOENIX CASTER COMPANY v. SPIEGEL. APPEAL FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE DISTRICT OF INDIANA. No. 150. Argued December 10, 1889.- Decided March 3, 1890. The claim of letters patent No. 190,152, granted May 1, 1877, to Alexander C. Martin, for an "improvement in furniture casters," namely, "The floor-wheels EE, the anti-friction pivot wheel F, the housing B, the elliptical housing opening, or its mechanical equivalent, and the rockerformed collar bearing, or its mechanical equivalent, all combined so as to allow the floor-wheel axis to oscillate horizontally, substantially as and for the purpose specified," being a claim selected by the patentee in obedience to the requirements of the Patent Office, after an extended construction of it had been rejected, and being a combination of specified elements, must be limited to a combination of all such elements. In view of the state of the art, the words in the claim, "the rocker-formed collar bearing, or its mechanical equivalent," must be restricted to such a bearing resting on a collar beneath the floor-wheel housing, as is shown in the Martin patent; and the claim does not cover a caster which does not have the collar of that patent, or its rocker-formed collar bearing or an equivalent therefor. IN EQUITY to restrain infringements of letters patent. The case is stated in the opinion. Mr. Charles P. Jacob for appellant. No appearance for appellee. MR. JUSTICE BLATCHFORD delivered the opinion of the court. This is a suit in equity, brought in the Circuit Court of the United States for the District of Indiana, by the Phoenix Caster Company, an Indiana corporation, against Augustus Spiegel, Henry Frank and Frederick Thoms, to recover for the alleged infringement of letters patent No. 190,152, granted May 1, 1877, on an application filed September 16, 1876, to Alexander C. Martin, for an "improvement in furniture casters." Opinion of the Court. The specification, claim and drawings of the patent are as follows: "This invention relates to swivelling casters, and the objects of the invention are to secure in such casters freedom from pivotal wear of carpet or floor and increased mobility in swivelling. The first object is attained by the use of two floor-wheels whose axes are coincident, in connection with devices which insure the contact of both wheels with the floor, regardless of ordinary irregularities of floor surface. The second object of the invention is a natural result of the suppression of floor friction. In the accompanying drawing, Fig. 1 is an elevation of my improved caster. Part of Fig. 1 is a vertical section. Fig. 2 is a side elevation, and Fig. 3 is a part elevation, exhibiting the portion cut away in Fig. 1. Common casters, in swivelling, pivot upon the floor. The point of pivot motion is the point of contact between wheel and floor. Such pucker and wear carpets, and are sluggish in their swivelling action. Two rollers side by side will, in swivelling, turn in opposite directions, and it will be found that they roll upon the floor instead of pivoting, as does the single wheel; but if the floor should be irregular, as is often the case, one wheel of the pair would not touch the floor, and the two-wheeled caster would become pratically a one-wheeled caster. My improvement consists in making the axis of the two wheels oscillatory with reference to the article to which the furniture caster is attached. The axis of oscillation, being at right angles to the floor-wheels' axis, allows the wheels to accommodate themselves to ordinary inequalities of floor. Referring to the drawing, A is a flange, from which depends the stem or boss C. This stem serves as a pivot for the swivelling motion, as a draft-pin for the wheel-housing, and as a means of uniting the parts. The housing B furnishes bearing supports for the two floor-wheels EE and the anti-friction pivotwheel F. The latter wheel is situated centrally between and vertically above the floor-wheels. The housing swivels upon the stem in the usual manner. Were only a swivelling motion of the housing desired, its fit upon the central pivot might be close, allowing only looseness enough for the swivelling action; but the object sought by my improvement demands that the |