that they existed for many years, and that they have been used.'

In charging the jury assembled to try the action of Cornish v. Keene (1 W. P. C. 508), Tindal, C. J., said that if the invention was at the time the letters patent were granted in any degree of general use; if it was known at all to the world publicly, and practised openly, so that any other person might have the means of acquiring the knowledge of it as well as the person who obtained the patent, then the letters patent are void. Now it will be a question for you to say whether, upon the evidence which you have heard, you are satisfied that the invention was or was not in public use and operation at the time the letters patent were granted. It is obvious that there are certain limits to that question; the bringing it within that precise description which I have just given, must depend upon the particular facts which are brought before a jury. A man may make experiments in his own closet for the purpose of improving any art or manufacture in public use; if he makes these experiments, and never communicates them to the world, and lays them by as forgotten things, another person who has made the same experiments, or has gone a little further, or is satisfied with the experiments, may take out a patent and protect himself in the sole making of the article for fourteen years; and it will be no answer to him to say that another person before him made the same experiments, and therefore that he was not the first discoverer of it, because there may be many discoverers starting at the same time, many rivals that may be running on the same road at the same time, and the first that comes to the Crown and takes out a patent, it not being generally known to the public, is the man who has the right to clothe himself with the authority of the patent and enjoy its benefits. That would be an extreme case on

one side; but if the evidence, when properly considered, classes itself under the description of experiment only, and unsuccessful experiment, that would be no answer to the validity of the patent. On the other hand, the use of an article may be so general as to be almost universal. In a case like that you can hardly suppose that any one would incur the expense and trouble of taking out a patent. That would be a case where all mankind would say, "You have no right to step in and take that which is in almost universal use, for that is, in fact, to create a monopoly to yourself in this article without either giving the benefit to the world of the new discovery, or the personal right to the value of the patent, to which you would be entitled from your ingenuity and from your application." Therefore it must be between these two limits that cases will range themselves in evidence; and it must be for a jury to say whether, supposing those points to be out of the question in any particular case, the evidence which has been brought before them convinces them that the subject of the patent was in public use and operation at that time, at the time when the patent itself was granted by the Crown. If it was in public use and operation, then the patent is a void patent, and amounts to a monopoly; if it was not, the patent stands good.'

The case of Carpenter v. Smith (1 W. P. C. 530) arose out of an alleged infringement of a patent for an improved lock. 'I think,' said Lord Abinger to the jury, that what is meant by "public use and exercise” is this a man is entitled to a patent for a new invention, and if his invention is new and useful, he shall not be prejudiced by any other man having invented that before, and not made any use of it; because the mere speculations of ingenious men, which may be fruitful of a great variety of inventions, if they are not

brought into actual use, ought not to stand in the way of other men equally ingenious, who may afterwards make the same inventions and apply them. A great many patents have been taken out, for example, upon suggestions made in a celebrated work by the Marquis of Worcester, and many patents have been derived from hints and speculations by that ingenious author. But yet, as he never acted upon them, as he never brought out any machines whatsoever, those patents are good. So that the meaning of these words, "public use," is this: that a man shall not, by his own private invention, which he keeps locked up in his own breast, or in his own desk, and never communicates it, take away the right which another man has to a patent for the same invention. Now "public use means this: that the use of it shall not be secret, but public. If a man invents a thing for his own use, whether he sells it or not,-if he invents a lock, and puts it on his own gate, and has used it for a dozen years, that is a public use of it. If it were otherwise, see what the consequence would be. If Mr. Davies has a lock which he directed to be made and put on his gate sixteen years ago at least; if that was not a public use which prevented a man from taking out a patent, any man might go and take a model of that lock, and get a patent for it. How can he be the inventor of it? Because, to obtain a patent, a man must be the inventor; and if it has been once in public use, that is, used in a public manner, not used by the public, yet if it has been used by half a dozen individuals, or one,' in a public manner, any man having

If a person' (asked Dallas, J., Hill v. Thompson, 1 W. P. C. 240) 'had done precisely all that is specified to be done in this specification, and had not communicated it to any one, could he be prohibited by the patent from doing that which he had done before, though known to no one but himself; or could it be considered as new, if practised by only one person, but not communicated to the world?' And Tindal, C. J., in Cornish v. Keene (1 W. P. C. 511),

access to it, how can he be said to be the inventor, if by merely gaining access to that he takes out a patent? A man cannot be said to be the inventor of that which has been exposed to public view, and which he might have had access to if he had thought fit.' The same judge subsequently said, in the same case, 'If you are of opinion (not that they were generally adopted by the public and used by the public, for that, in my opinion, is a perfect fallacy) that the use of them is public, and the exercise of the invention was public, and not kept secret so that the public might have no benefit from it, then I think that part of the issue you ought to find for the defendant.' The learned judge summed up the evidence as to a public user in this way-Twenty-six years ago Freer produced to Tilsley a model of a lock, and desired him to make six dozen like it, and afterwards a dozen and a half. Tilsley employed Walker to execute the order, and gave him the model. The locks were made, and Freer paid for them. Here you have an article manufactured by an English manufacturer, and sold; and in my opinion, if it was sold even for the assumed purpose of being sent to America, I cannot but think that that would be a destruction of the novelty of the plaintiff's invention. When a model is sent to a workman, who sells seven and a half dozen, and sells them for a certain price, I must say I think the invention was used and publicly exercised. There is no secrecy in the manufacture of them; it is not shut up in the closet of the workman who makes them, but the man who makes them gives directions to another workman; he sells them for his own profit.'

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observed that if the defendants had shown that they practised it (i.e. the patented invention), and produced the same result in their factory before the time the patent was obtained, they cannot be prevented by the subsequent patent from going on with that which they have done.'

These observations of Lord Abinger were made at the trial of an action which terminated in favour of the defendant. On the motion for a new trial, on the ground of misdirection, the judges of the Court of Exchequer expressed themselves satisfied with his lordship's view of the law and refused a rule, Alderson, B., saying that 'public use means a use in public, so as to come to the knowledge of others than the inventor, as contradistinguished from the use of it by himself in his chamber.'

At the trial of Hancock v. Somervell (Newton's L. J. vol. xxxix. p. 158), Mr. Justice Williams told the jury, that in order to rebut the patentee's claim of novelty, it was not necessary that the alleged invention should have been used by the public; it was sufficient if it were shown to have been in use in public, in contradistinction to secret use.

The point as to public use was again raised in an action for infringing a patent for paving streets with wooden blocks. It was shown that, some time before the date of the patent, the carriage way of the porch of Sir W. Worsley's dwelling-house in Yorkshire had been laid with blocks of wood, on a system apparently similar to the plaintiff's. Cresswell, J., told the jury, that if they thought the plaintiff's method of constructing the wooden pavement was the same as that adopted at Sir W. Worsley's, the invention must be deemed to have been made public. It had been publicly used, and made known to all persons who went to the house, so far as ocular inspection could acquaint them with it. Whether it had been used by one or used by five, the learned judge thought made no difference. (Stead v. Williams, 2 W. P. C. 136.)

In another action for infringing the same patent brought against another defendant, it was proved that the pavement at Sir W. Worsley's was on a different