what was done on board the Argus clearly did. It is said that this latter was a mere "experiment." No doubt, the plaintiff availed himself of the experience he obtained in the course of performing his contract with government to perfect his invention. But, in that sense, Stephenson, while constructing the great tubular bridge, might be said to have been engaged in an experiment. [CROWDER, J.-That would be a very different case from this. The contract there would be for the construction of the bridge itself. Here, the contract entered into by the plaintiff was, to lay down the telegraph cable; the manner of doing it being left to his discretion and judgment.] Nihil simul inventum est et perfectum. At what period may the inventor of a thing be supposed to cease to make experiments? Was one voyage to satisfy the plaintiff as to the operation and effect of his improved method? or was he to go on making voyage after voyage? If he is allowed to make one profitable use of his discovery before obtaining a patent for it, why not more? In Adamson's Case, 6 De Gex, M'N. & G. 420, there was but one user of the invention for profit, and yet that was held to be such a public use

*291] *of it as to avoid the patent. It is true that that was done under circumstances and conditions of greater publicity than could happen in this case; but the court cannot enter into nice considerations of the greater or less degree of publicity attending the user. The cases show that any user prior to the grant of the patent, whereby a knowledge of the invention is imparted to the public, avoids the grant: Wood v. Zimmer, Holt's N. P. C. 58 (E. C. L. R. vol. 3); Losh v. Hague, 1 Webster P. C. 202, Hindmarch 95; Carpenter v. Smith, 9 M. & W. 300,† 1 Webster P. C. 530, 534; Mullins v. Hart, 3 Car. & K. 297 (E. C. L. R. vol. 14). In Morgan v. Seaward, 2 M. & W. 554,† there was no user in the carrying into effect any contract: the invention was not used at all for any beneficial purpose: nor was it a thing that was capable of being used by itself. The arbitrator in stating this case has guardedly omitted to state that what was done on board the Argus in the Black Sea was a mere experiment. It is plain that, at the time the plaintiff put the cone on board that vessel, he had not made up his mind to apply for a patent: but that he afterwards did so in pursuance of an intention to take out a patent, if he found it desirable.

M. Smith, in reply.-1. The infringement seems to be conceded. 2. The provisional specification sufficiently describes "the nature of the invention:" it was not necessary that it should go on to describe the mode of carrying it into effect; that being the office of the complete specification. And there is no substantial variance here between the two instruments. The use of the rings was a mere mode of carrying the invention into effect,-for managing the apparatus in drawing the cable off the cone. But, supposing there was a variance, it would not, in the absence of fraud, avoid the patent: Cook v. Pearce, 8 Q. B. 1044 (E. C. L. R. vol. 55). 3, 4. The *arbitrator expressly finds that *292] the experiments at the works at Gateshead were incomplete and unsatisfactory. Indeed it is manifest that no experiment, except upon a scale which would be impracticable unless conducted as this was, would have sufficed to enable the inventor to judge of the utility of his invention. The circumstance of the experiment having been tried in the performance of a contract which, if successful, would produce profit, does not make it the less an experiment. Besides, the contract with

government was, for making and laying down the cable, not for the apparatus whereby the operation of laying it down was to be performed. In Bentley v. Fleming, 1 Car. & K. 587 (E. C. L. R. vol. 12), it was held, by Cresswell, J., that, if the inventor of a machine lend it to another, in order to have its qualities tested, and that other use it for some weeks in a public room, this is not giving the invention such publicity as to deprive the inventor of his right to obtain letters patent for it. [CROWDER, J.-That case was moved in the court in banc, but upon another point: which so far strengthens its authority: 1 C. B. 479 (E. C. L. R. vol. 50).] In Coryton on Patents, p. 93, it is said "The question of 'user' is almost entirely one of fact, to be dealt with according to the circumstances of each particular case. In Hartley v. Howland, London Journal, 1852, the latitude given to the patentee was very great. The manufacture was glass, and the publication contended for the open use of the plaintiff's invention by the predecessor of the defendant during the period of three months (March to May, 1835), in a factory employing seventy men. The question put to the jury by the learned Chief Baron, was whether that constituted a sufficient publication to the trade and the world to deprive the plaintiff of the right to take out a patent. The jury found a verdict for the plaintiff." *If the [*293 question be one of fact, it is here disposed of by the finding of the arbitrator. Cur. adv. vult.

BYLES, J., now delivered the judgment of the court:The first objection of the defendants was, that the defendants' apparatus is not an infringement of the plaintiff's invention.

It was for the arbitrator to decide any question of fact; and the court, therefore, are not at liberty to interfere with his finding, unless they see that there was no evidence of infringement before him. But the substitution by the defendants of a cylinder having a domed or hemispherical top, for the cone or the cone with the conoidal apex in the plaintiff's apparatus, both the plaintiff's and the defendants' apparatus being used for the same purpose and in nearly the same manner,is, in our judgment, not only evidence, but strong evidence, to support the arbitrator's finding.

The second objection was, that the provisional specification contained no mention of the rings claimed in the full specification.

But the office of the provisional specification is only to describe generally and fairly the nature of the invention, and not to enter into all the minute details as to the manner in which the invention is to be carried out otherwise the provisional specification must be as full as the complete specification, and drawn with as much care and deliberation. Indeed, the statute itself indicates this distinction between the provisional and the final specification; for, it calls the latter the complete specification,-implying that the former is, or may legally be, in some respects executory and incomplete. Moreover, it enacts (s. 6) that the provisional specification is to describe the nature of the invention, and no more: but when the statute comes to speak of *the complete [*294 specification, its language is altogether different: it enacts (s. 9) that the complete specification shall describe, not only the nature of the invention, but also the manner in which it shall be performed; and not only describe, but particularly ascertain it. We therefore think that the provisional specification in the case under consideration sufficiently

describes the nature of the invention, though it does not enter into a detail of all the means by which it is to be accomplished.

The third objection was, that the plaintiff's invention had been disclosed and published before the date of the letters patent.

But a necessary and unavoidable disclosure to others, such as here appears, if it be only made in the course of mere experiments, is no publication; although the same disclosure, if made in the course of a profitable use of an invention previously ascertained to be useful, would be a publication: In re Adamson, 25 Law Journ. Ch. 457.

The answer to this third objection, therefore, depends on the fourth and last and main objection, which was this,-That the use of the apparatus for profit before the date of the letters patent, was a use which avoided the patent.

It must be and is conceded, on the part of the plaintiff, that an inventor's public use, for profit, of an invention already ascertained by previous experiment to be useful, is a gift of the invention to the public, and avoids a subsequent patent. And it is conceded by the defendant, that a use before the patent, merely experimental and tentative, does not avoid it.

Now, the use here made of the invention in actually laying down the cable, was a use which partook of both characters. On the one hand, it was experimental and tentative; but, on the other, the experiment itself turned out, not only successful, but beneficial to the inventor at the moment.

*295] *The true question, therefore,-looking at the decision of the arbitrator, seems to be this: is an experiment performed in the presence of others, which not only turns out to be successful, but actually beneficial in the particular instance, necessarily a gift of the invention to the world?

We think it is not. In the case under consideration, experiments on dry land are found to be indecisive. The decisive experiment still remains to be made on a large scale, and in deep water. An opportunity presents itself, in the course of a government contract,-not a contract for the use of this particular apparatus, but a contract for laying down the cable by any means the contractor may select. The experimentor is obliged either to experiment in a way that may turn out to be useful in the particular instance, or else not to make any efficient and decisive experiment at all. The coincidence of an experiment with actual immediate profit or advantage from it, if successful, is unavoidable.

Suppose, even, that this coincidence had been accidental. Suppose that, in the course of the voyage, the inventor had tried some further and new experiment, with an alteration of the apparatus, which alteration had at once answered some useful purpose; surely that further invention would have been his property: otherwise, a man cannot have the property in an invention which starts from his brain so fully matured and armed that it not only succeeds at the first trial, but accomplishes on that very trial some profitable or useful purpose.

If, indeed, the plaintiff in the present case had on other and subsequent voyages used his apparatus, and unnecessarily delayed his application for a patent, he would have given his invention to the public. But here the arbitrator must be taken to have found, as he well might

on the evidence before him,-that the *inventor lost no time, but applied for his patent with reasonable expedition. There must, therefore, be judgment for the plaintiff.