they are exercising a legal right, or whether they are in- A. D. 1841. fringing the property of another. It is, therefore, indispensably necessary that the specification, taken together with the title, should distinctly denote what it is that the patentee claims as his invention, and of which he says that he is to be entitled to the exclusive use during a period of fourteen years. Now, looking at his title and specification, what is it that Mr. Neilson says he is to have the exclusive use of? His title is, "improved application of air to produce heat in fires, forges, and furnaces;" then during fourteen years are all mankind to be debarred from making any attempt at improving the application of air to produce heat in fires, forges, and furnaces? Well, then, when you come down to what he specifies, what does he specify? Does he specify a principle? Does he claim all modes by which heat is to be communicated to the air between the blowing apparatus and the furnace? I think my learned friend says that he does. He says that any mode whatsoever by which, in the intermediate space between the regulator (which is taken to be part of the blowing apparatus) and the blast furnace, heat is communicated, by whatever means, whether it be in a sphere, or in a cube, or in an enclosed vessel—of course it must be an enclosed vessel-[Parke, B.: It is not necessary, because Mr. Botfield's patent is one in which it is not. If it is the application of heat to a furnace in Mr. Botfield's patent, it is not by heating the air in an enclosed vessel.] Not in that part to which your lordship refers. [Parke, B.: Therefore I suppose what he claims is every method of heating the air in an enclosed vessel of any shape or description, between the Quod blowing apparatus and the furnace.] I suppose so. valeat non dixit if he did mean to say so, he has not said so; and that is one of my objections, because he has said no such thing, and one of the uncertainties and one of the ambiguities of which I complain is, that he has said no such thing; and then, I say, that if he had said so, without more particularly designating the method by which his process was to be carried into effect, he would only have rendered his specification more vicious.

But now let us examine the terms of the specification, which as you observe is without any drawing whatever. I believe that the almost invariable practice now is to accompany a specification with drawings-and why? Why the specification should be a working plan, it should enable the mechanic to carry the invention into effect. The rule, my lord will remember, in Mr. Watt's famous case was this, that a mechanic acquainted with the steam engine before Watt's invention should be able to perfect Mr. Watt's invention. Mr. Watt's invention was held to be properly specified, because a common mechanic-the word mechanic is used-because a mechanic

Sir J. Campbell for the defend

unts.

acquainted with the old engine before Mr. Watt's improvements, looking to Mr. Watt's specification and to nothing else, could make all Mr. Watt's improvements; and it was proved that they did make them. Here not a single instance is given of any person who, not having seen the apparatus before looking to the specification, made the apparatus and applied it to the smelting of iron. Notwithstanding all the pains that have been exerted-you see you have had witnesses called from Wales, from all parts of England, and from all the coal country and the iron country in Scotland-you have had scientific witnesses called merely to give speculative opinions-but you have had no one single instance brought before you of any person who, taking this specification in his hand, and not being previously instructed with the mode in which the hot blast was to be applied, constructed an apparatus whereby the hot blast was beneficially applied to the smelting of iron. Upon that ground, I say, the plaintiffs' case entirely fails. (The learned counsel then proceeded to examine and comment upon the specification.) We have been told that this is a vessel where you have one horizontal tube, another horizontal tube, and a great series of vertical tubes communicating with the horizontal tube, and stops in the horizontal tube whereby the air is propelled and made to cross from side to side so that it may be properly heated; and this is called a vessel. Why, in one sense it may be a vessel, as if it were twenty miles long and consisted of five thousand pieces. Why, you may call it a vessel if you like, but the specification is to speak the common language of mankind; that is a vessel which would be understood to be a vessel in common parlance, or at all events by a person of moderate skil in the department of art to which the discovery belongs. Throughout there not only is no suggestion of a succession of different pipes, but that is clearly excluded, because it is supposed that there is to be one vessel. Just observe. It is admitted that there is only to be one vessel as to the smith's forge; it is admitted that there is only to be one vessel as to the cupola. It is quite clear that the patentee contemplated that the same process was to be adopted in the blast furnace, only increasing the dimensions of the vessel or having two, that is, two to go in at different times. [Parke, B.: "Dimensions and numbers."] That is not multiplying the pipes; that is numbers ejusdem generis, vessels as before described, of the same construction, and on the same principle. The specification shows that Mr. Neilson contemplated that the air was to pass through his vessel without interruption, without any disc or any thing to detain it against the heating surface; it was to go through in a current. Then as to the size; this is to depend on the blast, and on the heat necessary to be produced. Thus, as the blast and heat to be produced are increased, so the size is

to be increased. That is utterly false, for if you were to in- A.D. 1841. crease the size in that proportion you would utterly fail; you would have a form which would not give the heating surface. This, then, is an entire misdirection; instructions are given which, if followed, must produce an inevitable failure.

Further, the following passage," the form or shape of the air vessel or receptacle is immaterial to the effect, and may be adapted to the local circumstances and situation," is totally false. The effect is producing heat in the air contained in the vessel; now it is perfectly well known, that although the air may be heated in a cube of a foot, yet if the cube be increased the air will not be heated at all. How then can the form be said to be immaterial?

There is another point, the omission in the specification of all mention of the water twire, which is entirely fatal. It is admitted that, without the use of the water twire, the hot blast cannot be beneficially used; the heat of the air is so great on entering the furnace, that unless there be some contrivance for cooling the pipe by which the heated air is injected, the application must fail.

For these reasons the specification is bad, and the patent cannot be supported. The legitimate object of the patent was the smith's forge and smelting cupola; for these Mr. Neilson might have had a valid patent, if he had entitled it properly and given a proper specification, but he has extended his patent beyond its proper limit, and endeavoured to embrace a subject for which he merely throws out a hint; in respect of the smelting of iron, it is a patent for an idea, not so much as a principle, and cannot therefore be supported (h).

PARKE, B., having stated the pleadings, proceeded as follows: Parke, B., to the Now, there is no question whatever in this case but that this jury. The summing up. invention of the hot blast, as used at the time this action was brought and some time before, is not simply beneficial, but highly valuable to the arts, and a very important discovery has been either made by Mr. Neilson, or he has led to a most important discovery, and there is no doubt that the invention he made was an invention which turned out to be ultimately an invention of the greatest utility, and I entertain no doubt or

(h) Notice of objections to be considered as part of the pleadings.-No witnesses being called on the part of the defendants, Sir W. Follett directed attention to the terms of the statute 5 and 6 W. 4, c. 83, s. 5, ante 260, n. a., respecting the notice of objections, and required them to be read. The question was then raised whether such reading at this stage of the cause would not give a right of reply.

Parke, B.: The words of the statute are, no objection shall be allowed to be made on behalf

of the defendant unless he prove the objections stated in such notice, not unless he prove the notice. I think it must be considered as a kind of notice appended to the pleas as a notice of set-off, and that therefore, in truth, the attention of the court should be called to it as part of the plaintiffs' case. Let them be simply read. The proper course would have been, I think, that they should have been read at the time of the pleadings being opened.

The objections were then read.

with a view to their defeat.

Parke, B., to the difficulty myself in adopting the observation that has been made jury. by Sir William Follett, as to the mode in which these questions Patent rights are of patent right are to be decided. Half a century ago, or even not to be tried less, within fifteen or twenty years, there seems to have been very much a practice with both judges and juries to destroy the patent right, even of beneficial patents, by exercising great astuteness in taking objections, either as to the title of the patent, but more particularly as to the specification, and many valuable patent rights have been destroyed in consequence of the objections so taken. Within the last ten years or more, the courts have not been so strict in taking objections to the specification; and they have endeavoured to hold a fair hand between the patentee and the public, willing to give the patentee, on his part, the reward of a valuable patent, but taking care to secure to the public, on the other hand, the benefit of that proviso which is introduced into the patent for their advantage, so that the right to the patent may be fairly and properly expressed in the specification. Upon this occasion I have only to invite your attention to the evidence, and to desire you to decide all questions arising upon the specification, without any bias on either side, with no desire to give the public the benefit of this patent by tripping it up, but fairly to exercise your judgment between the patentee and the public.

Now, the best way of disposing of this case, I think, will be to take those questions in order upon which you are to pronounce your opinion; and the first is, whether the defendants have been guilty of infringing the patent? and I apprehend that there is no doubt they have, if the patent be a good patent, and if the specification be free from the objections that are raised to it; and if the specification is to be understood in the sense claimed by the plaintiffs, the invention of heating the air between its leaving the blowing apparatus and its introduction into the furnace, in any way, in any close vessel, which is exposed to the action of heat, there is no doubt that the defendants' machinery is an infringement of that patent, because it is the use of air which is heated much more beneficially, and a great improvement upon what would probably be the If the invention machine constructed by looking at the specification alone; but consist in apply still it is the application of heated air, heated in one or more ing the air heated while in transitu, vessels between the blowing apparatus and the furnace, and then, however therefore if it should turn out that the patent is good, and the specification is good, though unquestionably what the defendants which the de- have done is a great improvement upon what would be the fendants' apparatus may be on species of machinery or apparatus constructed under this in the specifica- patent, it appears to me that it would be an infringement of tion, it is no less it; therefore your verdict upon that issue would be for the an infringement. plaintiff, provided it is for the plaintiff on the other issues. In case it should not be, there may be some little difficulty in dis

great the im

provement

that described

posing of that issue; possibly that difficulty may not arise (i). A.D. 1841. If it becomes necessary, I will give you directions on that part

of the case.

The second objection is, that the said Neilson was not, at the time of the making the said letters patent, the true and first inventor of any invention for the improved application of air to produce heat in fires, forges, and furnaces, where bellows and other blowing apparatus are required. Now, upon the evidence in the case, none of the witnesses who have been called on the part of the plaintiff are aware of any invention similar to this; but there has been an account given by them-by two-of a discovery made by a Mr. Botfield, who is said to have taken out a patent, though we do not know exactly what it was. Botfield's discovery was never carried into effect; they say it was unlike the present mode of heating air, and according to the account that was given by those gentlemen who are acquainted with Botfield's process, it appears to be different, because the main principle of that discovery, according to their account, was the application of gas and flame to the easier smelting of iron stone in the furnace, and the introduction of hot air was only in addition, and that hot air came over the stove which was introduced into the twire hole, without being kept in an enclosed vessel (k). And it would appear that Botfield's invention was not the plaintiff's invention; therefore, that would dispose of the issue that the plaintiff was not the sole inventor, and also dispose of the issue, that this invention had been used before. The defendants say in one plea, that he was not the inventor, and in another plea they say it was used before; but there is no evidence of any such use, except in the case of Botfield,

(i) The difficulty here suggested frequently occurs in practice, and the question is, whether, supposing a defendant to have been doing precisely the thing described and claimed in the specification, the plaintiff would be entitled to the verdict on the issue of not guilty, if the patent should not be good. The decision of this question under the new rules is of considerable importance with reference to costs; and the simple question is, whether in law a person can be guilty of infringing an invalid patent, whatever the ground of invalidity. In a recent case, Sandiford v. Neild and Others, cor. Lord Denman, C.J. (Trin. Vac. 1842), the defendants, who were calico printers, were using a particular method of arrangement of the pattern on the blocks, whereby they were enabled to print a complicated pattern of several colours, the cloth to be printed being advanced each impression of the block by some portion, as one-sixth of the width of the block. The defendants were charged with infringing the plaintiff's patent, both in respect of the arrangement of the pattern, and the advancing the cloth (or block) by spaces less than the whole width of the block. The defendants (amongst

other pleas) denied the infringement and the novelty of the invention (at least so far as it related to the alleged infringements), and that the parts in respect of which the infringement was alleged were not in themselves the subjectmatter of letters patent. The defendants had a verdict on the issue as to the novelty, the rest of the case not having been submitted by the Lord Chief Justice to the jury; whereupon Kelly and Webster contended that the defendants were also entitled to have the verdict on the general issue entered for them, both on the ground of the above verdict, and assuming that the parts in respect of which the infringement was charged were not the subject-matter. Sir F. Pollock, A.G., M. D. Hill, and Crompton, contra, contended that it was no less an infringement, however invalid the patent, whether from want of novelty or the invention not being the subject-matter of letters patent.

Lord Denman, C. J., directed a verdict for the plaintiff on the issue of not guilty, and the jury were discharged on the other issues.

(k) See Botfield's specification, ante 274, n.