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 a patent for an invention would or would not stand, if a similar invention had formerly been in use but had ceased to be used long before the date of the patent, and the thing had been completely lost sight of until discovered again and patented.

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.

If

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. 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?

An inventor does not lose his right to a patent by keeping his invention to himself after its completion, provided there is no profitable user of it (Bentley v.

Fleming, 1 C. & K. 587). But it may be remarked that, although not destructive of his right, delay is here especially dangerous, and the fact might, under certain circumstances, be used as a strong argument against a patentee.

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 by the patentee 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. C. 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. Seward (1 W. P. C. 194), an action which arose out of Galloway's patent for 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 specifi

cation. 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.
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 July 22, 1829, and it was assigned by him
to Morgan. Upon these facts it was contended that
the invention, at the date of the letters patent, was not
new, in the legal sense of that word. Parke, B., deli-
vered 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, in-
deed, any use of the machine in a foreign country
before the date of the patent. If the term "manufac-
ture" 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 in-
junction was observed; and this makes the case, so far,
the same as if they had been constructed by the in-
ventor'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

After remaining
After remaining a short time,

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 publicly-that 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 to be what is usually called a publication of the invention in England, would be to defeat a patent by much slighter circumstances than have yet been permitted to have that effect.'

Adamson invented certain machinery whilst engaged in the execution of a contract for the erection of a pier. This machinery he used on the works for four months before he applied for a patent. It was held that there had been public user, inasmuch as he had derived a profit from the employment of the invention after its utility had been ascertained, and during all that time the public had free access to it, so that he was not entitled to a patent. (Re Adamson's Patent, 6 De G. M. & G. 420.)

It is clear from the preceding cases that an inventor, who intends to patent his invention, should be extremely