invention, is a

employed unless there was either a water twire in which the A.D. 1841. water circulates and is constantly kept cool by the circulation, or some other equivalent protection for the entry of the pipe into the furnace. Now, if that should be your opinion, another The omission to objection to the specification is open-it omits to make all mention in the specification any mention of water twires or other protection; for if this appa- thing which may ratus would not be beneficial without them, then in that case be necessary for the beneficial it is of no use to the public as it is described in the specifi- enjoyment of the cation, and the specification would be bad. That, I think, fatal defect. would be clear. Then the question of fact arises, whether you are satisfied upon the evidence of those gentlemen, one of them a practical gentleman; and I call your attention to what has heen spoken by Mr. Penrice, who says-that in point of fact they did use at the Calder Iron Works twires of the ordinary description, dry twires, and that they continued to use them for two years, and also continued to use this process beneficially. Therefore that is evidence to be set off against the other. Whether they could use the process in the simplest form beneficially, is left in matter of doubt; but unless they could use the process in the simplest form in which a man would make this according to the specification, it appears to me that the objection as to the twires is also a good objection to it, because then that ought to have been introduced, and it is not beneficial unless it is introduced. Therefore it is not a good subject of patent unless those twires are added to the apparatus as described in this specification; and on that ground it would appear to me that the specification was defective. Then you will have the But aliter if such omission go goodness to attend to that evidence; and if you come to the only to the deconclusion, that without the water twires, though more bene- gree of the beficial with them, there still would have been an apparatus which would work beneficially, and be worth while to set up, the objection founded on the water twires vanishes.

nefit.

Now, gentlemen, with respect to the evidence:-Mr. Russell (the first witness) says, that looking at the generality of the specification, and the complicated form of the arrangements in such a case (semble, present improved state), a workman would not be able, directed and instructed by the specification alone, to complete such an apparatus as would be most efficaciously used. That, however, is not the exact point. The point is, whether it can be used beneficially, taking it in the simplest form. If, in order to use it beneficially at all, experiments were necessary, about which a good deal was said by the Attorney General, then the specification would be void. If it were If the apparatus necessary to use experiments in order to have the benefit of the described can be used beneficially invention in which it is claimed by the specification, in that in its simplest case it would be void; but if in this case it is only necessary to jection that great have recourse to experiments in order to have the full benefit improvements that the subject is capable of, it appears to me that it would not made.

form, it is no ob

may have been

Parke, B., to the void the patent, because, though it is a subject beneficial in its jury. simplest form of application, it is a vast deal more useful when the improvement takes place; and in order to make the greatest improvement, unquestionably many experiments are necessary; and even at this very moment, notwithstanding the great improvements that have taken place, there is no doubt that the matter is not in that state of improvement which in all probability it will be in the course of a few years. It does not appear to me, therefore, that what the Attorney General has dwelt upon with reference to the evidence, all the evidence in the case, that that affects the patent. If experiments were necessary to produce any degree of benefit under the patent, then, in that case, I think the specification is void, for it does not give the requisite degree of temperature; but if the simplest form would be productive of benefit, it appears to me that the specification is good.

Mr. Jessop, who has been for forty years in the iron trade, describes the cold blast, and the impression he was under, that inasmuch as the works operated better in winter than in summer, it was a good thing to have the pipe conveying the cold blast protected from heat by means of being enclosed; and the next witness, also well practically acquainted with the subject, was of the same opinion, and painted white a portion of the regulator in order that the air might come in a cool state. This turned out to be a perfect mistake, as subsequent experience has shown, and that the cold has nothing to do with it; that it was only from the dryness of the atmosphere; but there is no question about the hot blast being a great improvement. Mr. Jessop describes the saving consequent on the adoption of the hot blast, and says—“I have read the specification, and I do not think that any one practically acquainted with the subject would have the least difficulty in constructing the ap paratus." Now, this is the opinion of a gentleman well acquainted with both the principle and the practice: "We used the water twires with the cold blast, and I heard of it in other places; we used it occasionally when the blast did not enter the furnace properly; when the heat was of a nature to injure it, we used it with the hot blast regularly. It is possible to use it without, the effect being that the twire would be soon destroyed, and it increases the expense.' But, on cross-examination he says, it is possible to do without the twire, but not without some substitute. "I think we could not use the hot blast without either the water twire or some other protection different from that which was used in the cold blast." If that is right, the specification is defective; but whether it is right or not, you are to decide. "I have not tried myself experiments at any temperature below 200 degrees Fahrenheit to ascertain whether it is worth the expense; but if a less degree

of heat is required, there would be less fuel, and any degree of A. D. 1841. heat would make it worth while to adopt the alteration, therefore any description of vessel will produce some degree of heat." Then he describes what the water twires are. "I believe they have always been used in refineries. I have known them some years; but not the same sort of water twire has been used. There was water at the sides and the top on those, but not at the bottom. We employ improved twires in our refineries. We never used the water twire for the hot blast. For the cold blast we used the water twire. The sides of the furnace began to burn, then we applied the water twire. Sometimes a twire would last only a night, sometimes it would last for six months. It would not be prudent, but it is not impossible to do with the common twire when the furnace is hot. If the supply of water were cut off, and the twire melted, then the inconvenience would be that the works would stop for two or three hours— that is, the blast would not go on. Of course the iron ore would be made in the furnace. The blast would not go on for two or three hours, until that was repaired." That is an inconvenience which he thinks would prevent the adoption of the hot air process. "Even water twires," he says, "would sometimes melt; with the cold blast we did not use it." Then the question is-"Is it not indispensable to have the twires when you use the hot blast?" The answer is " I do not know that it is indispensable, but it is desirable." He has not yet come to his final answer. "I think we could carry on our works beneficially without the water twire, but not so beneficially as with it. I think we could use the hot blast profitably without the water twire, but we should use fire clay. I think that we could not beneficially use the hot blast without the water twire, or some other protection different from that which we use in the cold blast." He speaks of the Low Moor Works having gone on for a time; that they used the hot blast, and afterwards discontinued it. Then he had a retort plan; in fact, a tubular form. He is asked-"If you have a vessel with a sufficient heating surface, and bring the heat in contact with it, it will answer with a vessel of any shape? A box would not answer so well, because there is a large interior space which you do not bring in contact. You may accomplish the object by having the interior vessel or interior plates." Then he says, upon re-examination-"Any one who knows the process of smelting, would know that if heat were increased you must have recourse to some method of guarding the pipe; and he would naturally have recourse to a water twire, which was well known before." Now, I asked him that question ultimately; because no doubt this will be put in a different shape hereafter, to take the opinion of the court upon, whether that circumstance would cure this omission in the patent.

Parke, B., to the jury.

Mr. Mushett says " I have been connected with iron works since 1792. I always used the cold blast, and never until this patent heard of the hot blast; there is no iron master who would not, with his workmen, arrange an apparatus for heating the air sufficiently, so as to produce a beneficial effect in the blast furnace. The water twires were sometimes used with the cold blast. It has been known for forty years that if in the aperture the twires melted the water twires would relieve that." He says, that one effect produced has been the manufacture of iron from ore which would not produce it before. He speaks also with respect to Botfield's patent, and he says that does not in the slightest degree represent the present invention. Then he says, "There is a feeling on the part of the iron trade, that the friction of the air in passing through is a bad thing. An iron master would not use a vessel of this sort which produced friction. The advantages of heating the air are counterbalanced by the friction." It appeared afterwards, from Mr. Farey's evidence, that there are two things to be attended tothe current of air, and also the heat, one being rather contrary to the other; and experience alone, and probably experiment, would ascertain what was the best. He says-" I have never seen any apparatus except in a tubular form; I never saw it in the shape of a square; and I never saw it in the shape of a box." He says " In my opinion, a workman would form a straight vessel; that is from the prejudice he has to the tortuous form for the passage of air." He says "I should have tried that which produced the greatest heat on the surface. I might have tried a cylinder, or long box, with a blowing apparatus, without any thing to direct the current of the air in the first instance. I should have made experiments in the first instance. If experiments I should at first make it ten or fifteen feet long." I have told you, that if experiments are necessary in order to construct a machine to produce some beneficial effect, no doubt this specification is defective. If experiments are only necessary in order to produce the greatest beneficial effect, in that case, I think, the patent is not void. "I should at first make it ten or fifteen feet long. The air would have been heated there, and carried into the blast furnace. It would have succeeded to a certain extent, which would give me grounds for persevering. I should have gone on with my experiments, if I had grounds for proceeding with my experiments." He says—“ I have never tried the experiment, but I have no doubt the advantage arising from a heating vessel ten or fifteen feet long, supposing there was no farther improvement, would have counterbalanced the expense of setting it up." He is of opinion that, in the simplest form that would suggest itself to any one, there would be a beneficial result. "I have never seen the process so conducted. The next experiment would be to lay another hori

are necessary

for the production of any beneficial effect, the patent is void.

zontal pipe next to that. The next thing to try would be a A.D. 1841. communication pipe. I have heard the term condy pipe, but can attach no meaning to it. I should have come to the result of using pipes from the specification alone, with experiments, in perhaps five or six months, if I had gone on with vigour and perseverance. The quality," he says, "may be deteriorated from overcharging the furnace. Hot blast iron is sold at an inferior price." He says" It is compensated on the whole by the greater production from ores which were stubborn before, and upon the whole the iron is improved; and looking at the specification, and seeing what is there mentioned as to ten thousand cubic inches being required for the cast iron form of cupola, and applying it to a smelting furnace, I should have increased, not the dimensions, but I should have increased th heating surface particularly; I should not have increased the dimensions solely. I do not know exactly the shape, but I should have tried to have got the greatest heating surface possible." That is looking at the specification. He says there is no reference to the heating surface in the specification. The vessel may be of any form, provided it contains ten thousand cubic inches. It speaks of capacity, not form; it leaves the form, as to the heating the surface, to the convenience of the manufacturer.

Mr. Penrice, a mining engineer, was in the employ of the Calder Company, and superintended the apparatus used in 1826. The cold blast was then used, he had never heard of the hot blast, and he believes it was first used in January, 1829. He describes that it was first used with a malleable iron vessel, seven feet long, and thirty-six inches diameter, being a cylinder, that was interposed between the blowing apparatus and the furnace, with internal partitions. That was enclosed in brickwork. There was only one of them at first, and then there was another introduced, which had not these partitions in it. Now The omission to if you should think the patentee knew that these partitions which the pastate any thing were useful, and omitted to state that in this specification, tentee knows to that would make the specification void. You will consider be useful, is a whether that was so. He does not seem to be fully aware of the nature of his own invention, for he tried another cylinder without any of these partitions in it, seeming to think that no advantage was derived from those partitions, because he sent another cylinder to the place without any partitions in it at all. It is plain which of the two would be most likely to answer, but that does not appear, I think, on the evidence. And, of course, if the introduction of these were necessary to make the square box or the round box operate beneficially, in that case also the patent would be void, because that is not introduced as a necessary circumstance into the specification. Then he says with respect to the twires-" At first we had dry twires, and we

fatal defect.