conversion of iron into cast-steel; for although the plaintiff only mentioned carburet as a well-known substance which he put into the crucible, his patent was held to cover every mode of operating whereby carburet of manganese, however formed, was made to act upon iron. The result by the two processes was identical. The process used by Smith, the defendant in this action, was similar to that of the five manufacturers. If it was the same as the plaintiff's, he had a good defence ; for the process was not new, and the plaintiff's patent was invalid : if it was not the same as the plaintiff's, then there was no infringement.

Where the defendants at the trial of an action for the infringement of a patent for a method of manufacturing penholders, proved that they had made penholders according to the method which the plaintiff afterwards patented, and that such penholders had been placed in their warehouse for sale, though no sale was proved, Jervis, C. J., the presiding judge, held that the plaintiff's invention was destitute of novelty. (Mullins v. Hart, 3 Car. & K. 297.)

It may here be stated that when previous public user of the invention is relied upon as ground of the invalidity of a patent, it is not necessary to show that such user continued up to the time of the patent being granted. Even if discontinued, the patent will be invalidated. (The Househill Co. v. Neilson, 1 W. P. C. 709, in the House of Lords.) Their lordships, however, in delivering judgment in this case, expressly left it an open question, whether, if an invention had been formerly used and abandoned many years before, and the whole thing had been lost sight of, the patent would or would not stand.

The point whether prior secret user is sufficient to vitiate a patent has never been judicially decided; but we have a dictum of Mr. Justice Erle, uttered in the

above case of Heath v. Smith-" If one party only," said that learned judge, "had used the process, and had brought out the article for profit, and kept the method entirely secret, I am not prepared to say that then the patent would have been valid."

PRIOR USER BY INVENTOR.

We now come to a series of cases which declare the law with regard to a user of the patented invention before the date of the patent-not by other persons than the patentee, but by the patentee himself. If such a user by the patentee be tantamount to a publication of the invention, then the patent is just as invalid as if the invention had been publicly exercised by others. What, then, is the kind of user which will have this fatal effect upon the patent privilege?

In Bramah v. Hardcastle (Holroyd, 81), which was an action for infringing a patent for a water-closet, it appeared that the patentee had made two or three of these machines before he obtained his patent; but it was admitted that this fact would not of itself invalidate the patent.

If, however, the article has been manufactured for sale, and offered for sale, although not sold, this will be such a user of the invention as will render a subsequently obtained patent bad. (Oxley v. Holden, 8 C. B. N. s. 666.)

But where delay occurs in the issue of a patent without the patentee's fault, the manufacture of articles before the date of the patent for the purpose of being sold after the date, will not render the patent invalid. (Betts v. Menzies, 4 Jur. N. s. 477.)

In Wood v. Zimmer (Holt, N. P. 57) it appeared in evidence that a great quantity of verdigris made according to the patented process had been sold by the

inventor in the course of four months before the patent was obtained, and Gibbs, C. J., held that "the public sale of that which is afterwards made the subject of a patent, though sold by the inventor only, makes the patent void."

In Morgan v. Seaward (1 W. P. C. 194), an action which arose out of Galloway's patent for improvements in machinery for propelling vessels, which consisted in an improved method of constructing paddle-wheels, it was given in evidence that before the date of the patent, Curtis, an English engineer, made for Morgan, the managing director of the Venice and Trieste Company, two pairs of wheels, upon the principle mentioned in the patent. Galloway, the patentee, gave instructions to Curtis under an injunction of secrecy, because he was about to take out a patent. The wheels were completed and put together at Curtis's factory, but not shown or exposed to the view of those who might happen to come there. After remaining a short time, the wheels were taken to pieces, packed up in cases, and sent to Venice in April, 1829. Curtis deposed that they were sold to the company, without saying by whom, and Morgan paid Curtis for them. Galloway obtained a patent on the 22nd of July, 1829, and it was assigned by him to Morgan. Upon these facts it was contended, in an action against Seaward and others, for an infringement of the patent, that the invention, at the date of the letters patent, was not new, in the legal sense of that word. Parke, B., delivered the judgment of the Court of Exchequer, before whom the point was argued, in these words :-" The word 'manufacture' in the statute must be construed in one of two ways: it may mean the machine when completed, or the mode of constructing the machine. If it mean the former, undoubtedly there has been no use of the machine, as a machine, in England, either

by the patentee himself or any other person; nor, indeed, any use of the machine in a foreign country before the date of the patent. If the term 'manufacture' be construed to mean 'the mode of constructing the machine,' there has been no use or exercise of it in England, in any sense which can be called 'public.' The wheels were constructed under the direction of the inventor, by an engineer and his servants, with an injunction of secrecy, on the express ground that the inventor was about to take out a patent, and that injunction was observed; and this makes the case, so far, the same as if they had been constructed by the inventor's own hands, in his own private workshop, and no third person had seen them whilst in progress. The operation, indeed, was disclosed to the plaintiff Morgan; but there is sufficient evidence that Morgan at that time was connected with the inventor, and designing to take a share in the patent. A disclosure of the nature of the invention to such a person under such circumstances must surely be considered private and confidential. The only remaining circumstance is, that Morgan paid for the machines, with the privity of Galloway, on behalf of the steam company; but there was no proof that he paid more than the price of the machines, as for ordinary work of that description; and the jury would also be well warranted in finding that he did so with the intention that the machine should be used abroad only by this company, which, as it carried on its transactions in a foreign country, may be considered as a foreign company; and the question is, whether this solitary transaction, without any gain being proved to be derived thereby to the patentee or to the plaintiff, be a use or exercise in England of the mode of construction in any sense which can be deemed a use by others, or a public use, within the meaning of the statute and the patent. We

think not. It must be admitted that if the patentee himself had, before his patent, constructed machines for sale, as an article of commerce, for gain to himself, and been in the practice of selling them publiclythat is, to any one of the public who would buy-the invention would not be new at the date of the patent. This was laid down in the case of Wood v. Zimmer, and appears to be founded on reason; for if the inventor could sell his invention, keeping the secret to himself, and when it was likely to be discovered by another take out a patent, he might have practically a monopoly for a much longer period than fourteen years. Nor are we prepared to say that if such a sale was of articles that were only fit for a foreign market, or to be used abroad, it would make any difference; not that a single instance of such a sale, as an article of commerce, to any one who chose to buy, might not be deemed the commencement of such a practice, and the public use of the invention, so as to defeat the patent. But we do not think that the patent is defeated on the ground of the want of novelty, and the previous public use or exercise of it, by a single instance of a transaction such as this, between the parties connected as Galloway and the plaintiff are, which is not like the case of a sale to any individual of the public who might wish to buy; in which it does not appear that the patentee has sold the article, or is to derive any profit from the construction of his machine, nor that Morgan himself is; and in which the pecuniary payment may be referred merely to an ordinary compensation for the labour and skill of the engineer actually employed in constructing the machine; and the transaction might, upon the evidence, be no more in effect than that Galloway's own servants had made the wheels; that Morgan had paid them for the labour, and afterwards sent the wheels to be used by his own co-partners abroad. To hold this