of operation, to produce any new effect. Wheels, with their known modes of operation, and known. combinations, must be of very extensive employment in a great variety of new machines; and if they could not, in the new invention, be included in the patent, no patent could exist for a whole machine embracing such mechanical powers.' "Where a specific machine already exists, producing certain effects, if a mere addition is made to such machine, to produce the same effects in a better manner, a patent cannot be taken for the whole machine, but for the improvement only. The case of a watch is a familiar instance. The inventor of the patent lever, without doubt, added a very useful improvement to it; but his right to a patent could not be more extensive than his invention. The patent could not cover the whole machine as improved, but barely the actual improvement. The same illustration might be drawn from the steam-engine, so much improved by Messrs. Boulton and Watt. In like manner if to an old machine, some new combinations be added, to produce new effects, the right to a patent is limited to the new conbinations."

"On the other hand, if well known effects are produced by machinery in all its combinations entirely

new, a patent may be claimed for the whole ma

An eminent jurist remarks that "in the present improved state of the arts, it is often a question of intrinsic difficulty, especially in cases of the invention of minute additions to complicated machinery, to decide whether one machine operates upon the same principle as another, and whether that which is stated to be an improvement, be really new and useful." And he proceeds to suggest, upon the authority of the above decisions of Mr. Justice Story, that, in determining whether a machine is an improvement upon those already known, or substantially the same," the material point of inquiry is, not whether the same elements of motion, and, in some particulars, the same manner of operation, and the same component parts are used, but whether the given effect be produced substantially by the same mode of operation, and the same combination of powers in both machines."72

Here we observe that the criterions proposed are, first the diversity of effect; second, the diversity of method. Mr. Justice Story, in one of the cases cited

71 Whittemore v. Cutter, 1 Gallison, 478. See also opinion of Mr. Justice Story, in Odiorne v. Winkley, 2 Gall. 51. 72 Kent's Com. Vol. 2, p. 370, 2d edit. Lect. 36,

above, proposes the combination of these two circumstances as a criterion. But his meaning doubtless is that these are characteristic of an improvement constituting an invention which may serve to distinguish it where other characteristic distinctions are wanting; and Chancellor Kent, would not probably be understood to lay down a different doctrine. The use of different elements of motion, or different mechanical principles or combinations offer equally marked grounds of discrimination, which are no less to be resorted to, than the method of operating and the result. Indeed the result or effect can scarcely be considered a criterion, for this by itself is not, as we have seen, patentable. In order to distinguish whether an alleged invention is patentable as such, and not merely a slight, immaterial, formal variety of what was already known, whether patented or not, we must look, not at a part merely, but at all of the characteristics of a patentable invention, the elements, principles, method or mode of operation, and according as we find these, originally, more or less combined in the alleged improvement, it will appear proportionably more or less satisfactorily to constitute the basis of a patent.

The following case in the Court of King's Bench, in England, illustrates what may be considered as amounting to a patentable improvement. A patent was

granted for an improvement in the manufacturing of chain cables. The improvement was alleged to consist in so applying the link to the force to operate on it, that that force should operate in one place, namely at the end; and this was effected by having a broad-ended bar across, instead of a conical one, which broad-ended bar lapped round the link, instead of perforating it; the former bars weakened the link, and they were weak in themselves, and if broken, there would be a pressure in some other part. The links were to have circular ends, and sides nearly parallel, but bulging out towards the middle. Abbott

C. J. As at present advised, I am inclined to think that the combination of a link of this particular form, with the stay of the form used by the patentee, although the form of the link might have been known before, is so far new and beneficial as to sustain a patent." Bayley J. was of the same opinion." In this case a link of the same form had been before in use, and it had been strengthened by a bar across it, but a change of the form of this bar, and the manner of attaching it to the link, was considered, and as it should seem with very good reason, by Chief Justice Abbott and Mr. Justice Bayley, to be a good founda

73 Brunton v. Hawkes, 4 B. and Ald. 540.

tion for a patent. The case went off, however, upon other grounds.

Sec. XII.-CHANGE OF FORM, PROPORTIONS, OR MATERIALS. INSUFFICIENCY OF THE INVENTION. ORNAMENTS.

The second section of the act of Congress of Feb. 21, 1793, c. 55, s. 3, which authorizes a patent for an improvement, declares "that simply changing the form or the proportions of any machine,or composition of matter, in any degree, shall not be deemed a discovery." This construction would undoubtedly have been put upon the law without any such express exception. It is indeed but the branch of a more general rule in giving a construction to the law, namely, that any change or modification of a machine or other patentable subject, which would be obvious to every person acquainted with the use of it, and which makes no material alteration in the mode and principles of its operation, and by which no material addition is made, is not a ground for claiming a patent. To permit a formal, trivial change in an article to be patentable, or a reconstruction of it upon substantially the same principles, with unimportant differences in form or proportions,