when fed up to the machine, a great variety of watered patterns might be given. The object of the invention was stated to be the production of an indefinite variety of patterns, as well as a bright finish or lustre. This patent failed to stand the ordeal of an examination in the courts of law, on account of the patentee having claimed too much. It was proved that the use of a patterned roller, in combination with a bowl moving at the same speed, was not new in the operation of embossing fabrics, and that the use of a plain roller and bowl moving at different rates of speed was well known in the operation of finishing or calendering fabrics. It was therefore held that the patentee's combination, ast stated in the specification, was not a patentable invention. Had he restricted his claim to the use of a patterned roller with circular grooves (which alone produced the watered effect) in combination with a bowl, the two moving at different rates of speed, for a specific purpose, viz. the double operation of finishing the fabric and producing a watered effect by one process, there is ground for supposing that he might have retained his patent. (Ralston v. Smith, 9 C. B. n. s. 117; 11 C. B. N. s. 471; 11 H. L. Cas. 223.) We may refer to the cases of Booth v. Kennard, (2 H & N. 84) Saunders v. Aston (13 B. & Ad. 886; 1 W. P. C. 75 n.), and Haworth v. Hardcastle (1 W. P. C. 484), as further illustrations of this point.

We must not forget, however, the remarks made by Jessel, M. R., in the case of Frearson v. Loe (L. R. 9 Ch. D. 58): 'It does not follow that because an inventor thinks he has invented more than he bas in fact, and describes the advantages of his invention, and some of these advantages arise from an old portion of the invention, it may not still be a good patent, provided that the invention as claimed is so limited as to fail to cover the actual thing in use, while it covers

some of the advantages mentioned; in such a case it may still, no doubt, be a good patent.'

It was also decided by the House of Lords in The British Dynamite Company v. Krebs (Goodeve's cases, p. 88) that an appendant claim to something old did not vitiate a patent. In this case the patentee had claimed the manufacture of the dynamite which was found to be new and also claimed the means of firing by special ignition as described. Some of these means of firing being old and well-known as applied to other explosives, the House of Lords construed this claim as being only appendant to dynamite and upheld the patent. It is not, however, advisable for inventors to make claims of this kind, which if held to extend the patent would invalidate it, and if held not to extend it are simply useless.

Must not make large speculative claims.

A patentee will not be allowed to make wide hypothetical or speculative claims based on mere conjecture or surmise, nor will his patent be permitted to cover matters of which he was ignorant at the date of his patent. In the specification under a patent for improvements in machinery for raising water, the patentee said, 'If any gases or elastic media other than atmospheric air are used, with which to charge the case [part of the machinery], I claim the sole right to do so.' Pollock, C. B., who tried an action brought for infringing this patent (Tetley v. Easton, Macr. P. C. 48), remarked upon this passage, that he had no hesitation in saying that, in point of law, the patentee had no right to make such a claim, and he went on to state that the law would not permit a patentee to claim more than he has invented. It will permit him to claim that which he has invented by means of successful experiments or otherwise, and which he has given to the public, but not that which is the mere subject of his

speculation or imagination, or of his endeavouring to grasp more than he is entitled to. I think we are bound to give, as far as possible, the fullest effect to an invention; but, on the other hand, I think we are also bound to oppose the endeavours to make a patent grasp at and embrace a number of matters that were never in the head of the inventor.'

In another part of the specification, the patentee described a wheel with straight arms, and then he said,

I propose to construct the wheel of every variety of configuration, so long as it is constructed with a channel in the interior.' The defendant had made use of a wheel with bent arms, and the patentee treated this as an infringement, although he admitted that at the time he obtained his patent he had never thought of bent arms, and also that curved arms almost trebled the effect of the machine. The judge told the jury that the patentee's claim to every shape of arm would not stand. To hold that it was good would be to reward a man who had rashly and ignorantly taken out a patent on a subject he had not appreciated. The same learned judge, when presiding at the trial of Stevens v. Keating (2 W. P. C. 184)-an action for infringing a patent for processes for combining materials to form cements,-said, with reference to that part of the specification which was held to claim. the use, not only of a particular acid, but of all acids which might succeed, that no patentee could be allowed to make such a claim, and to say, Whereas other substances will succeed, I claim them all.

A perusal of these cases will show that it is safer for a patentee to restrict his claim to the use of those processes, or those materials, which he has found by actual trial to answer the purpose, than to extend it to matters of which he has no accurate knowledge; since, in doing this, he may either claim something which will not

answer the object in view, something which is not new, or something which he does not sufficiently describe. The law will aid him, without any general claim in his specification, in repressing infringements which are an illegal imitation of his process behind a colourable variation, or by means of mechanical or chemical equivalents.

'The safest course for patentees to adopt' (said Pollock, C. B., to the jury on the trial of Crossley v. Potter, Macr. P. C. 256) in framing their specifications is, instead of including everything, to confine themselves specifically to one good thing, and a jury will always take care that if that be a real invention, no man under colour of improvement shall be allowed to interfere with that which is the offspring of their genius.'

Ambiguity to be eschewed.

The fatal effect of ambiguous language in a specification is illustrated by the case of Hastings v. Brown (17 Jur. 648; S.C., 1 E. & B. 454). A patent was obtained for arrangements for raising ships' anchors, and the specification claimed as the invention a cable-holder to hold without slipping a chain cable of any size,' but it could not be gathered from it whether the inventor claimed a cable-holder to hold chain cables of any one size, or to hold chain cables of different sizes. Now, a cable-holder to hold a chain cable of any one size was already known at the date of the patent. The patentee,' said Lord Campbell, when the case was argued before the Court of Queen's Bench, on a motion to enter a nonsuit, ought to state distinctly in his specification what is his invention, and to describe the limits within which he is to enjoy a monopoly. That is not done in this case with respect to the nature of the cable-holder. What is

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claimed [in the pleadings] is a right to construct a capstan which will raise chain cables of different dimensions. Does the plaintiff disclose in his specification that he claims that invention? If it is only claimed with regard to one cable, then there is no infringement of the patent. The vice of the specification is, that it is quite equivocal what the claim is. There is nothing in the title which at all assists us; and when we look to the description in the specification, which speaks of "a chain cable of any size,” I think that the proper construction to be put upon the words is that they mean one chain cable." At all events, they are capable of that meaning; and if the specification is equivocal, it is bad.' And Mr. Justice Coleridge added, 'If the specification on a fair interpretation be equivocal, it is insufficient.' The rule for a nonsuit was accordingly made absolute.

Must not describe two methods when only one is effective.

If two methods of doing a thing are described in the specification, and by one of these it cannot be done, the specification is bad. (Regina v. Cutler, Macr. P. C. 137; Beard v. Egerton, 8 C. B. 165.)

Medlock's specification of his invention for making red and purple dyes from aniline commenced the description of the process thus: I mix aniline with dry arsenic acid and allow the mixture to stand for some time, or I accelerate the operation by heating it to or near its boiling-point until it assumes a rich purple colour, and then I mix it with boiling water and allow it to cool: when cold it is filtered and decanted.' When the case went before the House of Lords, it was held, in affirmation of the view taken by the Lord Chancellor, that on the construction of the whole specification two processes, a hot and a cold process,