The question whether one thing is a mechanical equivalent for another is a question of fact for the decision of a jury. And the fact, that a new machine includes what is contained in the old, but contains an improvement besides, will not the less make it an infringement.2 Where a patent is taken out for a combination of different parts without expressly claiming the parts taken separately, this will be deemed impliedly to include such of the several separate parts as are new and material to the process. And where a patent includes a combination of several things, one of which is material but not new, this will avoid the whole patent on the ground of its being a fraud on the Crown or a false suggestion. And it is an infringement to use or sell or offer the article for sale in this country, though it was made abroad, or where the patent did not extend.5 The using of a patented article by a purchaser, who cannot be supposed to know whether the person making it infringed a patent or not cannot be construed as an infringement, and yet the person selling it may infringe, for it is his business to know such a matter. Yet where a retail dealer unwittingly sells articles which are an infringement of the patent he cannot be sued by the patentee, if he give full information as to the persons from whom he obtained the articles complained of."

Injunction against infringement of patent.—Whether and on what terms an injunction will be granted to prevent the infringement of a patent depends on the prima facie indisputability of the title, and the nature of the mischief likely to be caused to the patentee and the infringer respectively by a temporary toleration or stoppage of the sale. And the court will not assist a patentee in this way unless he apply very promptly after knowledge of the infringement. The rule is, that where a person has been long in the enjoyment of a right undisputed and undisturbed, he shall have the protection of an injunction against an

1 Morgan v Seaward, 1 Webst. P. C. 170.

2 Electric Co. v Brett, 10 C. B. 838; Hall v Jarvis, 1 Webst. P. C. 100. 3 Lister Leather, 8 E. & B. 1004. 4 Morgan Seaward, 2 M. & W. 544. 5 Neilson Betts, L. R., 5 H. L. 1; Walton v Lavater, 8 C. B., N. S. 162; Oxley v Holder, Ibid. 666. 6 Gibson Brand, 4 M. & Gr. 179, 196. 7 Betts v Willmot, L. R., 6 Ch. 239. 8 Smith v

L. & S. W. Co., Kay 408; Boville Crate, L. R., 1 Eq. 388.

invader, until such invader shall establish his rights by action. He shall be held to have a right to have his enjoyment protected, any disturbance of which it would be so difficult to compensate. On the other hand, it is true, it would be nearly as difficult to compensate the defendant if he be unjustly restrained.1 The court can grant an injunction before the hearing where the patent is an old one, and the patentee has been several years in undisturbed enjoyment of it, or where the conduct of the defendant is such as to enable the court to say, that, as against the defendant himself there is no reason to doubt the validity of the patent. But the user must be of an active kind, and not merely nominal.3 And evidence of actual infringement must also be shown. Thus when an injunction is asked for to restrain the infringement of a patent, the court has reason to consider first the validity of the patent; secondly, the fact of the infringement; where those two facts are established, it is within the power as it is the duty of the court to grant the injunction. And where the infringement has not been proved, but only an extreme probability that it will take place, the court will equally grant the injunction. When the validity of the patent is clear and has been established, the court will order an account of all the profits made by the infringer; and if the patent has expired, the account will include all the unsold articles made while the patent was in force. Nevertheless, upon the decree against infringement the patentee is not entitled to have both an account and profits and an inquiry into damages. He must elect which of the two forms of relief he will adopt.s

Questions for jury on trial of patent actions.-In all cases the question of novelty of an invention must be mainly one of fact, and therefore usually to be tried by a jury. Nevertheless, it may be impliedly involved in a subsidiary point, such as prior publication in a book of large circulation, describing the mode of making or using

1 V. C. Wood, Betts v Menzies, 3 Jur. N. S. 357. 2 Dudgeon v Thomson, 30 L. T., N. S. 244. 3 Plimpton Malcolmson, 44 L. J., Ch. 257. 4 Betts v Willmott, L. R., 6 Ch. 239; Neilson Betts, L. R., 5 H. L. 1. 5 Bridson v Macalpine, 8 Beav. 230. 6 Adair v Young, 12 Ch. D. 13. 7 Crossley Beverley, 1 R. & My. 166. 8 De Vitre v Betts, L. R., 6 H. L. 319.

the invention.1 And where the question is as between two processes whether they are substantially the same, and hence that the later one was no invention at all, this also is a question for a jury.2 But if the processes are described in two specifications, those being in writing, the construction is then a question of law for the court; or at least the court must first explain to the jury the respective constructions of the documents, and then ask the jury if they are the same thing.3 A court cannot itself compare two inventions so as to pronounce them identical, but must ask the jury to say if this is so. The question what is a proper subject for a patent is a question of law, though this may in turn depend on the prior ascertainment of certain isolated facts to be determined by the jury: as, for example, if it is only an instance of an old process applied to a new occasion, in which case it is not patentable; or if it is a more economical and cheaper mode of making a thing already in common use, in which case it is patentable."

Extending, altering, and repealing patent.-A power is vested in the Judicial Committee of the Privy Council by statute to extend the term of a patent by seven years on good cause shown, which usually means the inadequate profits of the patentee in proportion to the merit of the invention. For such applications are by no means granted as matters of course.7 And they are never granted except on a very clear and precise account of the extent of the remuneration hitherto obtained.8 And if the patent is assigned, sometimes it is made a condition, that an annuity shall be granted to the original inventor by the assignee during the extended term. As it sometimes happens, that a patent has been granted under circumstances which import fraud on the Crown, it may be repealed by scire facias; and the grounds on which the court gives judgment do not

1 Lang Gisborne, 31 Beav. 133; Stead v Williams, 2 Webst. P. C. 126. 2 Steiner Heald, 6 Exch. 607. 3 Betts v Menzies, 10 H. L. C. 117; Hills v Evans, 4 De G., F. & J. 288.

4 Delarue Dickenson, 7 E. & B. 738. 5 Losh v Hague, 1 Webst. P. C. 202. 6 Crane Price, 1 Webst. P. C. 408. 7 7 & 8 Vic. c. 69, § 4; Honiball's Patent, 9 Moore, P. C. 393; Pitman's Patent, L. R., 4 Pr. C. 87. 9 Russell

4 Pr. C. 87.

8 Saxby's Patent, 9 Moore, P. C., N. S.. 82. Ledsam, 1 H. L. C. 687; Russell's Patent, L. R.,

materially differ from many of the defences set up in actions by patentees against those who infringe the patent.

In some cases the patent may be amended after sealing, and also there may be a disclaimer and memorandum of alteration.

Object and origin of trade mark.-While copyright and patent right are founded on the same essential principle, namely, that he who creates or originates a valuable order of words, or a valuable corporeal article or process, should be insured in the use of these and in turning them to the best advantage, so the use of a trade mark is often adopted to single out some superior article which the manufacturer is confident cannot be surpassed in quality, though it may be imitated by inferior workmen or salesmen. In a trade mark there is less of the inventive faculty and less of intellectual labour than in copyright and patent right. Yet as many articles of commerce depend for their merit much on the manufacturer or producer, it is equally just that he should be protected in the benefits derivable from the public being able easily to identify and so secure whatever value attaches to such article when sold. The essence of a trade mark is thus to ear-mark one article from all other articles having this superficial resemblance. It thus very nearly resembles property.1

1 "This right cannot be properly described as a copyright; it is, in fact, a right which can be said to exist only, and can be tested only, by its violation. It is the right which any person designating his wares or commodities by a particular trade mark, as it is called, has to prevent others from selling wares which are not his, marked with that trade mark in order to mislead the public, and so incidentally to injure the person who is owner of the trade mark. Any one who has adopted a particular mode of designating his particular manufacture, has a right to say, not that other persons shall not sell exactly the same article, better or worse, or an article looking exactly like it, but that they shall not sell it in such a way as to steal (so to call it) his trade mark, and make purchasers believe that it is the manufacture to which that trade mark was originally applied."-L. Cran worth, L. C., Farina v Silverlock, 6 De G. M. & G., 217. "When it is said, there is no property in a trade mark, this must be understood to mean that there can be no right to the exclusive ownership of any symbols or marks universally in the abstract; thus an ironfounder, who uses a particular mark for his manufactures in iron. could not restrain the use of the same mark when impressed on cotton or woollen goods; for a trade mark consists in the exclusive use of some name or symbol as applied to a particular manufacture

Trade mark distinguished from patent.-The distinction between a patent and a trade mark is this, that the former in effect prohibits all other persons not only selling but making for sale the article which is patented, whereas a trade mark merely indicates who was the maker of the article, and does not in any way prohibit others from making precisely the same article and in the same way. And hence it is that many persons who besides using a trade mark add the word patent, as if to give it greater authority, disentitle themselves to the ordinary remedy for infringement of such mark, seeing that they themselves have resorted to a species of fraud or misrepresentation. For the use of the word patent deters manufacturers from examining and imitating, and perhaps improving on the original, and so benefiting the public. And one characteristic of trade mark, which does not belong to copyright or patent, is, that the trade mark of an alien will be protected by the courts as fully as that of a native.3

Use of trade mark is to identify maker of goods.The use of trade mark is thus a convenient mode of identifying the manufacturer or finisher of a particular article of commerce, which without some distinctive mark might be easily confounded with others nearly resembling it. It is a legitimate mode of signifying to the public this identification, as showing where, or by whom, or at what manufactory, an article was made; and as it tends to prevent deception and fraud the law lends its aid to protect the use of the mark, and so to enhance the value of the goods and secure to purchasers what they believe they are purchasing. It is beneficial to the seller and to the purchaser, for the latter being usually unaccustomed to distinguish minute differences, the mark is a patent and easily-ascertained mode of identification, saving him trouble and preserving him from mistakes. Supposing the rival trader to have

or vendible commodity, and such exclusive right is property. And for the same reason the plaintiff is entitled to relief, even if the defendant can prove, that he acted innocently and without any knowledge of the plaintiff's right."-Westbury, L. C., Hall v Barrons, 4 De G., J. & S., 150.

2 Flavel

1 Ford Foster, L. R., 7 Ch. 611. Harrison, 10 Hare, 467. 3 Collins Co. v Cowen, 3 K. & J. 428. 4 Spottiswoode Clark, 2 Phill. 154; Leather Co. v American L. Co., 11 H. L. C. 523,