party buying a patent article in a shop, and using it. He seemed to consider that the words, "whereby to pretend himself the devisor," overrode the whole clause. (0)

In Stocking v. Llewellyn, the bill alleged that the defendant had built and used patent cabs; an injunction was asked to restrain him from using them. The Vice-Chancellor stated that the relief was asked in respect of building; it did not appear that the defendant had built, but only that he had bought and repaired the cabs. The injunction was dissolved. with costs. (p) However, in Gillett v. Wilby, an action against the owner of a cabriolet for infringing a patent, Coltman, J. left the question to the jury whether the cabriolet alleged to have been an infringement was used or let out for hire by the defendant. No objection was taken by the defendant's `counsel to this ruling.(q)

9. An architect is not liable to an action for an infringement, where a contractor building a house and using the materials under his directions, employs in the construction of it, without license, articles which infringe a patent right. (r)

10. In a case before Vice-Chancellor Turner, the foreign owners of a ship, without fraud, and in ignorance of the patent, caused to be made and attached to their vessel, not being a British ship, in their own country, a screw propeller, on a principle which was covered by an English patent. The vessel came to England with a cargo for the purposes of trade. The Vice-Chancellor restrained by injunction the use of the screw propeller while the vessel should be within the waters over which the English patent extended.(s) In addition to the question whether the mere innocent use of a patented invention is an infringement, it may well be doubted whether in this case there was any use or exercise within the kingdom within the meaning of these words in the granting part of the patent. The coming of the vessel into our waters seems to have been merely incidental to the use and exercise of the invention in the ordinary course of the foreign

(0) Chanter v. Dewhurst, 12 M. & W. 825.

(p) Stocking v. Llewellyn, 3 Law Times, 33.

(q) Gillett v. Wilby, 9 C. & P. 336; Webst. P. C. 270; more fully reported 2 Carp. R. 540.

Denley v. Blore, 38 Newt. Lond. Journ. C.S. 224.

Caldwell v. Van Vlissingen, 9 Hare, 415; S. C. 16 Jurist, 115.

employment of the vessel on the high seas. The fact that, in coming to the shores of this country, the screw was used in English waters was merely accidental. The use seems to have been, in reality, no more a use in this country than would have been the use of a railway engine patented here in bringing trains from Scotland to a depôt on the border, not coming further into this country than would be necessary to enable an engine licensed here to take on the train. The arguments, from inconvenience, against the soundness of the decision, seem very forcible.

11. The Dutch government having remonstrated against the decision in the principal case, it was by stat. 15 &16 Vict. cap. 83, s. 26, epacted, that no letters patent for any invention granted after the passing of that Act should extend to prevent the use of such invention in any foreign ship or vessel which may be in any part of her Majesty's dominions, or in any of the waters within the jurisdiction of any of her Majesty's Courts, where such patent invention is not so used for the manufacture of any goods or commodities to be vended within, or exported from her Majesty's dominions. Provided

always, that this enactment shall not extend to the ships or vessels of any foreign state of which the laws authorize subjects of such foreign state having patents, or like privileges, for the exclusive use or exercise of inventions within its territories, to prevent or interfere with the use of such inventions in British ships or vessels, or in or about the navigation of British ships or vessels while in the port of such foreign state, or in the waters within the jurisdiction of its courts, where such inventions are not so used for the manufacture of goods or commodities to be vended within or exported from the territories of such foreign state.

12. The French law says, "Ceux qui auront sciemment recélé, vendu, ou exposé en vente, ou introduit sur le territoire Français, un ou plusieurs objets contrefaits, seront punis des mêmes peines que les contrefacteurs."(†)

Persons who in good faith have bought for their own use, and not for the purposes of trade, articles infringing the right of the patentee, may not be liable to the payment of damages, but the articles will be confiscated.

(t) Loi du 5 Juillet, 1844, sur les brevets d'invention, art. 41. See Guide Pratique des Inventeurs. Truffaut, Paris, 1844.

The following cases have been decided :-"Il faut que les produits étrangers aient été introduits avec une intention évidente de faire fraude à la loi Française. Celui qui a fait l'importation est excusable s'il a agi de bonne foi.”—Douai, 11 Juillet, 1846.

"Celui qui a acheté une machine réputée contrefaite ne peut être poursuivi à cause de l'usage qu'il en fait pour ses besoins personnels."-Rouen, 22 Mai, 1846.(u)

"Bonne foi ne peut être invoquée par celui trouvé en possession d'objets contrefaits destinés à être débités. Elle peut l'être par celui qui a acheté pour son usage un instrument qu'il ne savait pas être breveté."-Cour Royale de Paris, 3 Juillet, 1839; Cour de Cassation, 28 Juin, 1844.(x)

13. The American statute gives a right of action for damages in case of "making, using, or selling" the thing patented. (y) The Act of 1793 was repealed by the Legislature, and the present statute enacted, in consequence of a doubt whether the language of the former Act did not couple making and using together, so that making without using, or using without making, was not on offence.(z) In America the mere use of a patented composition, as the taking a patent pill, seems to have been considered as an infringement of the patent. (a) Mr. Curtis questions this so far as regards the use of things that perish in the using. But innocent purchasers will not be restrained from the use of the product of a patent machine, as the sale and use of bedsteads of a particular construction made by a patented machine, where the person selling or using them is not privy to the use of the patented machine.(b)

(u) Codes Annotés (Teulet, D'Auvilliers, et Sulpicy, Paris, 1850), tome ii. table générale 11. Perpigna, Manuel, &c. 364.

(x) Manuel des Inventeurs (Perpigna), 318, 354, 357.

(y) Act of July, 1836, ss. 5, 14, cited Curtis on Patents, 245.

(z) Per Story, J. Whittemore v. Cutter, 1 Gallison Rep. 429, 433; Curtis on Patents, 247.

(a) Per Story, J. Whittemore v. Cutter, 1 Gallison Rep. 433; Curtis on Patents, 258, 259; Curtis, Inventor's Manual, 109, Boston, 1851.

(b) Boyd v. Brown, 3 McLean Rep. 295; Boyd v. McAlpin, 3 McLean Rep. 427; Keplinger v. De Young, 10 Wheaton Rep. 358; Curtis on Patents, 250, 257.

SECTION II.-WHAT IMITATION OR RESEMBLANCE IS AN INFRINGEMENT.

14. The questions of infringement may be stated in these terms: Is the defendant's machine a copy made after and agreeing with that described in the plaintiff's specification? (c) Is the change, if any, colourable and formal, or substantial and essential? Is the effect the same, and is it produced substantially in the same manner and by the same means? Are the parts essential to the production of the useful result obtained by the plaintiff's invention adopted or imitated by the defendant?

15. If a defendant uses that which is virtually and substantially the invention described in the specification, a slight departure from the specification, for the purpose of evasion only, would be a fraud on the patent. The question is, whether the mode of working by the defendant has or has not been substantially different. (d) It is not in the power of any person, simply by departing in form, or in immaterial circumstances, from the mode of carrying out the invention mentioned in the specification, to use it without the leave of the patentee. The question is, whether there is such a variation in substance as to make the defendant's mode of operation a distinct thing.

16. The essence of the invention must be looked to. Gamble's patent was for the use of iron retorts worked in connection with each other, and heated by separate furnaces for the two stages of the process of manufacturing sulphate of soda, so that both might be kept in action at the same time. The material of which the chambers was composed not being of the essence of the invention, the patent right was held to be invaded by the use of chambers of other materials than those mentioned in the specification.(e)

17. In determining the question of the identity of two (c) Galloway v. Bleadon, Tindal, C.J. N. P. Webst. P. C. 523. (d) Hill v. Thompson and Forman, Webst. P. C. 239; 8 Taunt. 382, S. C.; Walton v. Potter, Webst. P. C. 587, Tindal, N. P.; Walton v. Potter, 3 M. & G. 411; per Gibbs, C.J. Bovill v. Moore, Dav. P. C. 405; S. C. 2 Marsh. 311; Stead v. Anderson, 4 C. B. 806. (e) Gamble v. Kurtz, 3 C. B. 435; Bramah v. Hardcastle, 1 Carp. R. 168.

mechanical contrivances, the jury must consider whether the defendant's machine is only colourably different, that is, whether it differs merely in the substitution of what are called mechanical equivalents for the contrivances which are resorted to by the patentee. If the differences which exist between one machine and the other are such as do not affect the principle of the invention, the two machines are alike in substance. One man has invented the principle and another has adopted it, and though he may have carried it into effect by substituting one mechanical equivalent for another, still the jury should look to the substance, and not the mere form; and if it is in substance an infringement, they ought to find it to be so. If its principle is not the same, but really different, then the defendants cannot be said to have infringed the patent.(f) Mechanics may be called as witnesses to prove the identity in principle of two contrivances.(g)

18. Mr. Justice Story says it is often a point of intrinsic difficulty to decide whether one machine operates upon the same principles as another. In the present improved state of mechanics, the same elements of motion and the same powers must be employed in almost all machines. The material question is not whether the same elements of motion or the same component parts are used, but whether the given effect is produced substantially by the same mode of operation and the same combination of powers in both machines.(h) Coleridge, J. said, "If the defendant has taken the same principle as the plaintiff, and has used it so as to work in the same way on the same subject-matters, so as to produce the same result, the only difference being that he has varied the mechanical agent by which he has done it, then I think it is merely a colourable imitation, and amounts to an infringement. It was stated by the witnesses on both sides, that it is often a matter of perfect indifference what mechanical agent they use to effect the result. The plaintiff has as much right to be protected against an infringement by the use of mechanical equivalents, as he would if exactly the same

(f) Morgan v. Seaward, Webst. P. C. 171, Alderson, B.; Morgan v. Seaward, Webst. P. C. 168, Sir L. Shadwell.

(g) Webster v. Uther, Godson on Patents, 232.

(h) Odiorne v. Winkley, 2 Gallison Rep. 51, 53, cited Curtis on Patents, 263.