These suits are brought by the plaintiff, to recover damages for the alleged violation of his patent, for an improvement on the plough. His improvement is, in part, made on the face, throat, and hind part of the mould-board. The counsel for the defendants have moved the court (1) to declare the patent void, because the specification, so far as it regards the improvements in the mould-board, does not describe this part of the improvement with the certainty required by the act of congress. See Act Feb. 21, 1703 (1 Story’s Laws, 301, § 3 [1 Stat. 321]). Should the patent be submitted to the jury, they then move that it be accompanied with the following instructions: 1. That so much of the patent' as respects the face of the mould-board is not violated, unless the defendants have adopted the same spheric lines as are described in the plaintiff’s specification. 2. That the jury must be satisfied that the former mould-board is described with sufficient certainty, to distinguish between it and the improvement claimed. 3. If the jury shall be satisfied that M’Cormick has made and used mould-boards, worked out by transverse and concave circular lines, before the plaintiff obtained his patent, or made his alleged improvement, then the particular spheric lines described in his specification constitute only a change of form and proportion, and is not an invention capable of being patented.
In the course of the argument, the counsel have also contended that the same uncertainty exists in that part of the specification which describes the throat and hind part of the mould-board, as in that which describes its face.
1. We will first consider the- proposition, that the patent is void for uncertainty. It is, undoubtedly, the province of the court to construe every written instrument offered in evidence; and it results from this duty, that if the instrument be so uncertain in its terms as to have no meaning; if it be insensible, or have no application to the case, it may be rejected. Is the patent, on which the present actions are founded, of -this descnp ¿ion? *157The specification, No. 1, relates to the face of the mould-board. It consists, first, of a general, and then of a mor.e particular description of this part of the improvement. The defendants contend that these descriptions are uncertain in themselves, and that there is also a fatal uncertainty -which of them describes the improvement for which the plaintiff claims his patent The plaintiff, after a general description of the mould-board then in use, and the inconveniences arising from its form, proceeds thus: “In order to meet and remedy the inconveniences arising from this form of structure, I form my mould-board into a different shape, and, instead of working the moulding part, or face of the mould-board to straight lines, my improvement is to work it to circular or spheric lines.” The specification then proceeds to a more particular description of the lines used, and of the manner in which they are applied, in order to form the face of the mould-board.
The counsel for the plaintiff seem disposed to consider this general description, as constituting the essential part of the specification, and the subsequent more particular description, as merely an illustration of the general principle, as one mode of carrying it into execution. If the specification will admit of this construction, then the subsequent and particular description may be expunged without affecting the patent A principle remains the same, whether it be accompanied by any case put for illustration or not. It may be comprehended more easily, but is not varied by the illustration. If we consider this general part of the specification as standing alone, and as describing this part of the improvement, it is not liable to the charge of uncertainty. It claims, as an improvement, “to work it (the mould-board) by circular or spheric lines.” Every mould-board worked by circular or spheric lines, however those lines may cross each other, and whatever may be their relative proportions, is within the plaintiff’s patent. If the face of no mould-board previously in use will fit this description, the plaintiff’s patent may, perhaps, legally cover the broad ground it would occupy. But if any mould-board previously in use would fit this description, then the piain-tiff would claim, as his invention, that which was previously known, and his patent would be void. But we do not think the specification will admit of this construction. It proceeds to say, “By repeated experiments I have ascertained that in one direction, viz.: from a, fig. 4,” (which is the point of the share) “inclining to the back part of the mould-board the circle or segment to which the mould-board is wrought, should have about three times the radius of the smaller segments represented by the letters c, c, &c., the former being about thirty-six inches, the Latter twelve.” This is intended for a plough whk-r- will turn a furrow-slice of twelve inches. The specification then proceeds to detail minutely the mode of operation by which these lines are to be applied, in order to give the face of the mould-board the required shape, and says: “The plough may be made larger or smaller, suited to deep or shallow ploughing by enlarging or diminishing the radii of the segments which it is wrought by.” “Believing,” the specification adds, “that this mode of shaping the moulding part, or face of the mould-board, is an original invention of my own, not heretofore used or known, and that it is a most important improvement in the shape of the plough, I claim the exclusive privilege of making, using, and vending the same.” This claim applies conclusively, we think, to the particular and laboured description of the mould-board which immediately precedes it. The language seems to us to requii’e this construction; and the subject seems also to require it. If the patent were to extend to all mould-boards worked out to circular lines, crossing each other in any direction, or in any proportion, it would be unnecessary to describe with so much labour and minuteness, the direction of the longitudinal and perpendicular circular lines, by which the face of the mould-board should be worked out, and the proportions those lines should bear to each other, and the size of the plough. It is obvious, then, that the person who makes his improvement to consist in the peculiar shape given to the face of his mould-board, and who describes the lines and their several proportions, which will give that peculiar shape, must, mean to appropriate the shape produced by the application of those new lines. We are then decidedly of opinion, that a mould-board conforming to the particular description contained in the specification, is the invention which the plaintiff claims, and that instead of being a mere illustration of the principle stated in the introductory part of the specification, it is itself the essential improvement, of which only a general idea was given in the introductory part.
It is contended on the part of the plaintiff that, if the patent be limited to the more par ticular part of the specification, still the claim is not confined to mould-boards worked out by segments of circles of the exact form and proportions mentioned in the specilication. To support this argument, counsel rely on the word “about,” which is introduced into the description; he has found, Mr. Davis says, by repeated experiments, that the segment of the larger circle should have about three times the radius of the smaller segments, &c. The claim, therefore, is not for a mould-board of the precise shape described, but for one “about” the shape described. It will at once be perceived, that unless the extent of this word “about,” be limited, it introduces all the uncertainty which it was supposed would be fatal to the patent, according to the general description contained in the introductory *158part of the specification. If, instead' of thirty-six inches and twelve, the proportions may he thirty-seven and eleven, thirty-eight and ten, why not forty and eight, or thirty-five and fifteen? The proportions may be enlarged or diminished, and with every change of proportion, the shape of the mould-board will be changed. If this be the construction of the patent, then it covers all the various forms of mould-boards which may be made under this latitudinous exposition of its terms; and if any mould-board has been previously used, whose face may be formed by transverse segments of circles, whose radii bear to each other “about” the proportion of thirty-six to twelve, the patent is void. "Will it be said that it may be left to the jury to determine, what is “about” the proportion particularly designated? This expedient will not remove the difficulty. We doubt how far it may consist with the principle that the court is to construe every written instrument But, .waiving this doubt, if the word has any limits, they must be always the same. When applied to a mould-board, it cannot be endowed,-with an elastic principle, to expand or contract itself according to circumstances. It cannot admit of being varied to a certain extent, if no mould-boai'd has been in use of. the shape which that degree of variation would produce,' and at the same time of being restricted, if a mould-board of such a shape has been in use. The word “about,” cannot be equivalent to a general claim of the exclusive right to all concave mould-boards, varying in any degree from those previously in use. The definiteness of the shape, which the specification professes to give to the mould-board, cannot be sacrificed by this loose word. It is further observable, that where the specification describes the process of the workman, it drops the word “about.” It has been supposed that the precise proportion required between the radii of the larger and smaller segments of circles, may be relaxed under the concluding part of the description. After giving the mode of operation, ,the specification adds: “This being thus worked off, uniformly forms a section of a loxodromic or spiral curve, and when applied to practice, is found to fit or embrace every part of the furrow-slice, far more than any other shaped plough.”
The argument is, that it is a mould-board whose face forms a section of a loxodromic or spiral curve that is patented, and that any lines which will give such a surface, are within the specification, and consequently, within the patent. _ Without noticing the difficulties growing out of this construction, it is sufficient to say, that the specification does not claim the loxodromic or spiral curve as the invention, but states it as the result of the prescribed application of the transverse circular lines, the application of which, in the relative proportions prescribed, is the invention. The language of this part of the specification, tends to confirm, we think, the opinion already indicated, that the plaintiff intended to claim a mould-board of the precise and definite shape prescribed, not one about that shape. He says his mould-board, “so worked off,” “when applied to practice, is found to fit or embrace every part of the furrow-slice, far more than any other shaped plough.” In construing this specification, we must keep in view the notice of the improvement which Mr. Davis claims to have invented and to describe. It is an improvement in the shape of a machine which has been in common use a great number of years, and in a great variety of shapes. The concave mould-board has been long considered as the most eligible shape that part of the plough can assume, and multiplied essays have been made to perfect it. Mr. Davis has recently added to their number; he professes to have discovered cthat precise concavity in the surface of the mould-board, which will better than any other fit every part of the furrow-slice, and, consequently, turn it over with less labour. For this discovery he claims a patent; we may reasonably "expect, that a specification for such a patent, will give a precise and definite shape to the improvement to be patented. We are then decidedly of opinion, that in construing this specification, the word “about” must be disregarded, and the patent be restricted to the mould-board as described, independent of that word. If we consider the particular part of the specification as describing the object to be patented, the defendants insist that the description given in that part is not sufficiently clear to enable a skilful mechanic to construct the machine. It may not, perhaps, be easy to draw a precise line of distinction between a specification so uncertain, ns to elaim no particular improvement, and a specification so uncertain as not to enable a skilful workman to understand the improvement, and to construct it. Xet, we think, the distinction exists. If it does, it is within the province of the jury to decide, whether a skilful workman can carry into execution the plan of the inventor. In deciding this question, the jury will give a lib-' eral common sense construction to the directions contained in the specification. See the able opinions of Mr. Justice Story, in Ames v. Howard [Case No. 326], and of Mr. Justice Baldwin, in Whitney v. Emmett [Id. 17,585],
If the patent be submitted to the jury, the defendants request the court to give the several instructions’ which have been already mentioned. 1. The first is, that so much of the patent as relates to the face of the mould-board is not violated, unless the defendants have adopted the same circular lines as are described in the specification. *159.This instruction will be given. ' 'But it may perhaps be understood with some slight -modification. The patent, undoubtedly, covers only the improvement precisely described. But if the imitation be so nearly ■exact as to satisfy the jury that the imitator attempted to copy the model, and to •make some almost imperceptible variation, :for the purpose of evading the right of the •patentee, this may be considered as a fraud •on the law, and such slight variation be dis■regarded. 2. The second instruction is, that the jury must be satisfied that the former mould-board is described with sufficient certainty, to.distinguish between it and the improvement claimed. We do not think a particular description of the former mould-board is necessary. A general reference to it, either in general terms which are not untrue, or by reference to a particular mould-board, commonly known, accompanied by -such a description of the improvement as will enable a workman to distinguish what is new, will be sufficient. 3. The court is ■also requested to instruct the jury that, if ■ M’Cormiek has made and used mould-boards, worked out by transverse circular lines, so as to produce a concave surface, before the plaintiff obtained his patent, or made his alleged improvement, then the particular lines described in his specification, ■constitute only a change of form and proportion, not an invention capable of being patented. It is stated on both sides, that the clause in the statute, to which this instruction refers, is one of considerable ■ doubt. It is in these words: “And it is hereby enacted and declared, that simply •changing the form or the proportion of any machine, shall not be deemed a discovery.” Act 1793, before referred to (1 Story’s Laws, p. 301, § 2 [1 Stat. 321]). In construing this provision, the word “simply,” has, we think, great influence. It is not every change of form and proportion which is declared to be no discovery, but that which is simply a ■change of form or proportion, and nothing more. If, by changing the form and proportion, a new effect is produced, there is not ■ simply a change of form and proportion, but a change of principle also. In every case, therefore, the question must be submitted to the jury, whether the change of form and proportion, has produced a different effect. With respect to the throat and hind part of the mould-board, the court need only say, that the description of the specification is general, not giving the particular shape of those parts of the mould-board. If either the throat or hind part of a mould-board, was in use before, which answers the de--seription contained in this specification, then the plaintiff has patented what belonged to •the public, and his patent is void.
NOTE. After the opinion of the court was delivered, both suits were dismissed agree!; ■ each party paying his own costs.