In the Matter of Brown's Patent. Varley and Delany as to the action of the condenser, but that does not entitle him to a Patent. Varley's instrument works as Brown's does. The condenser is a very old electrical device. Varley in Fig. 11 (ante p. 326) shows a tongue swinging in air towards Z and Z which are actually rotating drum surfaces. It is precisely the same in Brown's Fig. 9A. At first there were relays with a 5 condenser and fixed contact. Varley substituted a moving contact. The public cannot after that be prevented from using condensers with the moving contact. His second Specification dealt only with the substitution of the moving for a fixed contact, the use of condensers in that connection being well known. Whether Varley's explanation of the action is scientifically correct or not 10 does not matter. Delany, in Specification No. 3,839 of 1890, shows the same thing (ante p. 330, 1. 7) and refers to it as a known thing. The only difference between Brown and the prior inventors is in their ideas of the effects produced by a particular arrangement-merely a matter of theory. Where Claim 1 overlaps Claim 2 there is a different 15 problem. The action of a tongue insulated by air and making contact, normally with the drum as required, is quite different from that of continuous contact with a moving surface. The latter is one of merely diminishing the friction that interferes with the lateral motion of the tongue over the strips and insulating surface, p. 5, 11. 23-24 (ante p. 317, 11. 23 to 25). It is simply a mechanical 20 action. He described it in his paper as such, and pointed out that when the rotation of the drum was stopped the line current was too feeble to move the tongue laterally. Claim 2 differs from Claim 1 only in a small element-the insulating strips. They were not new, even in connection with a moving strface. Delany (510,005 of 1893) moved the tongue over the surface of the 25 plate in the direction of the length of the tongue. All that is in Claim 2 is in Delany's Specification: "The vibrations should be in a plane lengthwise of the "contact arm, or in other words parallel with the face of the contact, so that there "will be no tendency to jar the arm laterally." In that inventor's British Specification (No. 3,839 of 1890) there is shown an insulating strip between the 30 pieces on which the tongue moves. Normally it rests on the insulator. The tapping or pecking action of the tongue is produced by the electric vibrating arrangement a well-known device-there described. Delany disclosed the insulating strip and the moving of the surface and the tongue sliding across it from one conductor to the other. Then we come to the third Claim, which is 35 for "a receiving instrument short circuited through a closed circuit inductive "coil, for the purpose specified." According to the evidence of Prof. Boys, if the condensers act properly there is no use in this coil. The contention is that there is produced better definition of the signals by reason of having got rid of the irregular currents which produce the varying zero, p. 5, ll. 33-40 (ante 40 p. 317, 1. 34 to p. 318, 1.7). The varying zero is ascribed, p. 5, 11. 28-32 (antep. 317, 1. 30), to the charging-up action of the receiving condenser. It is further mentioned at p. 7, 11. 17-19 and 11. 31-52 (ante p. 320, 1. 42 to p. 321, 1. 22). The functions discharged by Brown's magnetic shunt are precisely the same as those discharged by the device described in his (Williams') book. [Counsel compared that descrip- 45 tion in detail with Brown's Specification.] The statement in the Specification that the charging of the condenser is the source of the trouble is contradicted by the evidence. There is no invention in the device claimed by the 3rd Claim. The whole thing is described in Varley's Specification (No. 3,453 of 1862). There is no invention implied in high inductance and low resistance. There was no difficulty 50 about that. There are no directions in the Specification how to get low resistance combined with high inductance. The 4th Claim is for "an inductive coil having. a closed magnetic circuit and provided with means for the initial excitation of "its core, substantially and for the purpose specified." This Claim is for the device shown in Fig. 17 and described at p. 8, 11. 35-48 (ante p. 322, 11. 34 55 to 48). The ends of the coil are connected (ante p. 322, 1. 36) "to any suitable source of electricity for exciting said coil, preferably by an alternating 66 66 In the Matter of Brown's Patent. "electric current." Now" any suitable source of electricity" would give either an alternating or intermittent current, or would give a continuous current. But the Patentee goes on to say "preferably by an alternating electric current," implying, of course, the possibility of the use of a continuous current. "Suitable 5"source of electricity does not mean suitable for this purpose. The true construction is that the current may be either continuous or alternating; the user may choose between the two, but the inventor prefers the alternating. If that be so the Claim is bad. Again at p. 8, 1. 46 (ante p. 322, 1. 47) the words "initially exciting" and the words "initial excitation " in Claim 4 to the mind 10 of an electrician point to the use of a continuous current. Dick and Kennedy (No. 3,658 of 1887) thought they could apply something of this kind by a continuous current. The Patentee has admitted in his evidence that Claim 4 could not be used with a continuous current. The 5th Claim relates to the duplex working, and at the receiving end the action of the closed circuit is 15 precisely the same as in the case of single transmission, therefore the objections to Claim 5 are the same as those to Claim 3. The 6th Claim is for the closed inductive coil in the fork of the bridge. The passages in the Specification which describe this in detail are at p. 4, 11. 10-14 (ante p. 316, 11. 16 to 20) and p. 8, 11. 22-28 (ante p. 322, 11. 22 to 28). Thereis no description whatever as to its resistance 20 or inductance. The result of all the objections to this Patent amount to this, that in connection with the feeble currents of submarine telegraphy no better contact has been shown or invented than the old contact, and as regards this receiving instrument through a closed circuit conductive coil, Mr. Brown seems entirely to misapprehend the use of it and the effect of it, but, both as regards 25 the use and effect, it is in Williams, and the only adjustment in the two being for high inductance and moderate resistance, that is a matter which any electrician can carry out as he desires. Evidence was given for the Petitioners by James Swinburne F.R.S., and Prof. Silvanus P. Thompson F.R.S. Their evidence was to the following effect :-It 30 was an old idea to have a tongue in air making contact with a moving part. A moving surface prevents sticking owing to microscopic fusion at the point of contact where the temperature would be high. Scraping action was also known; it was a much better contact. Figs. 8, 9, and 9A merely show an obvious thing to do, the same as rubbing one wire over another to improve the contact. When 35 rotating there is a microscopic trembling going on. The condenser—as to size of which no directions are given-is charged and discharged, and so improves the current at moments of making contact. If it be too large the action is sluggish, if too small it will not work. It prevents sparking, to which there is always a tendency. The roller contacts in Varley's Specification, No. 1,867 of 1866 40 (ante p. 326) are the same as Brown's. In Callendar's Specification, No. 16,718 of 1897 (ante p. 331) there is shown the movement of a tongue against the side of a wheel rotating, but in the direction of the length of the tongue; that is the same thing, there is no tendency to deflect the needle. In Delany's Specification, No. 3,839 of 1890 (ante p. 329) in Fig. 1, there is a needle moving in the plane of 45 the paper, and buzzing or " dithering" up and down, so as to be free to move sideways when not in contact. It differs from Brown's in degree only. On breaking contact the functions of the condensers are the same. Delany's condenser must also discharge the same functions as Brown's. There is no invention in shunting Varley's rotating contacts (Fig. 11, ante p. 326) as one 50 would do so unless directed to leave out condensers, their use being so well known. As to Figs. 1 to 7 of Brown's Specification, a "moving surface" is not confined to a rotating drum. Delany, in his U.S. Specification (510,005) showed relative motion of tongue and stop, which was always in the direction of length of the tongue; Brown has only continued that motion by revolving the surface. 55 As to the effect of the line condensers at the receiving end, there is no effect at the beginning of the signal, but afterwards it increases and finally stops the signal. Its discharge reverses the receiver or relay current, and gives a clear In the Matter of Brown's Patent. end to the signal before it is actually ended at the sending station. The capacity of the condenser must suit the cable and signals. A smaller condenser has a greater curbing effect. If suitably arranged for the cable it will neutralise the heaping up in the cable and send a counter E.M.F. The varying zero can be absolutely corrected by a condenser 5 of the right capacity. It is adjusted once for all for the maximum speed of the cable, and then there are no irregular currents. The condenser neutralises the earth currents in precisely the same way. But they are very slow and negligible. As there is an equal flow of electricity on either side of the condenser, the receiver may be placed on either side. In Varley's 10 Specification, No. 3,453 of 1862 (ante p. 324), an induction coil with resistance is inserted. There are two paths for the current to earth-the receiver with condenser, and the coil. The condenser and receiver are in fact shunted, the shunt producing induction. In his 4th mode (ante p. 325) the steady currents will split according to the resistances met. Magnetic induction 15 will choke one and work the relay. Varley's performs all the functions of Brown's with a correcting coil as well. Brown's shunt is in Varley's arrangement, with something more. An induction coil sets up a back E.M.F. on a change in the current. It acts like a condenser in that respect, only it must have resistance. But one must know its co-efficient of self induction, or inductance, 20 and resistance. The time constant is the ratio of the inductance to the resistance. The description by Williams of the magnetic shunt is easily understood by an electrician, though the language is sometimes confused. The delay in magnetisation and demagnetisation of the core (ante p. 327, 1. 21) is due to inductance and not hysteresis. The "extra currents go on after the pressure originally 25 causing the signal has been removed. He was in error in stating that their strength is proportional to the number of turns of wire, it should have been the square of the number. The coil is a closed magnetic one, as appears from the footnote (ante p. 327) and is shunted across the relay coils. It will counteract and reverse the tongue before the signal has ceased in the cable. The sharp end 30 of a signal is produced by reversal of the tongue caused by the higher inductance of the shunt sending a reverse current through the receiver. The cable is partly discharged at the receiving end through the relay end, is not entirely discharged at sending end. The beginning of the signals would be better without the shunt. It is introduced to deal with the evils introduced by the relay, and 35 self-induction is essential in the coil to overcome the inductance of the relay. The resistances must be approximately equal. Having the device described by Williams for dealing with single signals, there is no difficulty in making it do for a series. Paragraph 123 (ante p. 328) means that the coil acts in the reverse direction to the extra currents in the line. It helps to discharge the 40 line and while carrying errors introduced by the relay it has an additional effect in curing errors in the line. It differs from Brown's in degree. Such a use of a coil was common knowledge. It is mentioned in text books. [Certain text books were produced.] [Bousfield K.C.-I object to any particular book being put in to prove Common Knowledge.] [NEVILLE J.- 45 If these can go in there is no object in having to give Particulars. Common Knowledge is what most people conversant with the art knew. [Sir R. Finlay K.C.-We cannot give Particulars of these instances, Holliday v. Heppenstall, 6 R.P.C. 320, 326-7.] [NEVILLE J.-If you refer to a text book to show that a shunt (e.g. Williams') has been used for a particular purpose, you must 50 give notice of it as an anticipation. But it is different if you find therein a statement that it was common knowledge that shunts were used for draining off irregular currents. I shall admit it de bene esse.] [The witness then referred to a number of publications, one of which was a French publication. The learned judge held that it was not admissible.] In Delany's device, No. 3,839 55 of 1890 (ante p. 329), it is necessary to have either large condenser or very rapid vibrations. It would not work so well as Brown's, but could be made In the Matter of Brown's Patent. to work. The fusing action is greater than in Brown's, but the sliding contact of the latter is much better. In time the end of the tongue would form a groove with a hole at the zero point. Varley, when drawing up his Specification, 3,453 of 1862, knew about self-induction. A condenser and self-induction coil 5 give a time variation, but a resistance acts at once. Shunting the receiver with an electro-magnetic shunt is absolutely the same as placing a condenser and resistance in series. Self-induction without resistance acts the same as a condenser. But it is difficult to read this Specification without introducing modern knowledge. Varley thought that both self-induction and resistance were good, 10 Brown realised that self-induction was good but resistance bad, he therefore made the coil with a high inductance and low resistance. In his coil the time constant must be from to of a second, but he does not give that information. When the time constant is known the resistance and self-induction can be arranged. The time constant depends also on the condensers; if there are none, 15 then on the rate of signalling. With a periodicity of 5 per second and about 30 henries' inductance and a resistance of 30 ohms the time constant would be 1. It must be long enough to deal with a zero wandering over a long time. The self-induction is limited, for if too high it has the same effect as too large a condenser; the resistance of the coil therefore must be much lower than that of 20 the receiver. The difference between Varley's and Brown's inventions is one of degree and not of kind. They did not realise in the early days that the selfinduction must be right so as to drain away the right amount of current, and that the time constant must last over a signal; the result of compliance with these conditions is that the resistance of the coil must be low compared to that 25 of the receiver. As to public knowledge. Cable engineers know all about condensers and their use, but are not so familiar with coils; lighting engineers know more about coils, and have little experience of condensers. The former, however, do not publish the results of their work; others have much to learn from them. A 30 mathematical electrician would be familiar with both; a well-informed engineer would know that they were interchangeable. But there are cases in which they cannot replace each other. The term "making" and "breaking" contact (in Claims 1 and 2) is a well-known general expression and applies to both kinds of contacts. Sliding contacts of moving surfaces was well known, e.g., in clocks ; 35 but the use of condensers with them was new. Induction shunts were widely known, and were used to interrupt a rapidly varying current and allow a slow one to pass. They were called "Varley" shunts in 1893, and had been used with cables. The use of an induction coil to stop a telephone current, and of a capacity (or condenser) to stop a telegraph current, and thus separate one from the other, 40 was well known. It was shown in Lodge's Specification (No. 9,712 of 1898). Telephone currents go through the capacity but not the induction coil, whereas the telegraph signals go through the induction coil, and might get through the capacity. The correction of the varying zero was not previously done with a magnetic shunt. 45 Brown's statement in his Specification as to condensers (ante p. 320, 11. 42 to 51) is not accurate. In practice he must have had them too large. If the condenser is right then the "charging up" is its proper function required to improve signalling. If it be too large then the effect of reducing it is obtained by this use of the coil; it is an ingenious way of doing it. The paragraph (ante p. 317, 50 1. 26 to p. 318, 1. 13) is not clearly expressed, nor worked out properly. It will depend on the frequency of the coil whether the tongue has time to move backwards and forwards. There is no difficulty in making the arrangement in Fig. 14 (ante p. 321) by placing the coil in series with the receiver in the bridge. Sir Robert Finlay K.C., summed up the evidence for the Petitioners.-As 55 regards the first Claim the condenser is mentioned only in connection with one kind of contact, that is where the tongue moves to or from the surface and not to mere sliding contact. It cannot be an element in the combination in some In the Matter of Brown's Patent. The use cases and not in others. It is essential where there are two contacts. of the condenser was well known, and Brown alludes to it in the paper he published as a matter of common knowledge, the only difficulty being as to the theory of its operation. [NEVILLE J.-Three years after the date of the Patent.] But if the Claim included a condenser it is not new. The condenser was well 5 known since Varley's Patent in 1856, and it is not a patentable invention merely to point out that the use of an old device has advantages not known before. The latter part of Claim 1 refers to the device described by Varley in Specification No. 1,867 of 1866 (ante p. 326). Brown has not disclaimed by reference to previous Specifications, therefore one must put a plain meaning on his words. 10 [NEVILLE J.-The difficulty about Specifications is that the authors are perpetually hedging. If they would only state what they mean the invention to be, and then leave it to the law to say whether anything was an infringement of it or not there would not be much difficulty.] Claims 1 and 2 are too wide. A "moving surface" includes every form of motion such as vibration. 15 [Bousfield K.C.-I admit that if "moving surface" includes vibration we should be driven to amend the Specification.] If it does not include vibration it is anticipated by Varley's rotating rollers (ante p. 326). The surfaces with an insulator in the middle across which the tongue moved is described in Delany's Specification, No. 3,839 of 1890. [NEVILLE J.-You might have a combina- 20 tion of old parts producing a new result.] Anyway it does not amount to subject-matter. With regard to the drum, the whole thing, except the insulator, is disclosed in Varley's Specifications, No. 3,453 of 1862 (ante p. 324, 1. 54) and No. 1,867 of 1866 (ante p. 326, 1.31 to p. 327, 1.3). The drum with the insulator in the middle is merely an equivalent for the insulating table of Delany, No. 3,839 25 of 1890 (ante p. 330, 1. 2). It describes Brown's invention if the table be converted into a roller-a known equivalent. The sliding contact in the direction of the length of the tongue, as distinguished from vibratory contacts across air, were disclosed by Delany, No. 510,005, U.S. (ante p. 330), and Callendar, No. 16,718 of 1897 (ante p. 331). The third Claim is for "a receiving instrument 30. "short circuited through a closed circuit inductive coil, for the purpose specified." The purpose specified is the same as that specified by Varley in No. 3,453 of 1862 (ante p. 324, 1. 54) who describes the variation of the zero point and the "running together "of the signals. The closed inductive coil was old and is only claimed under the conditions noted on page 8 of the Specification (ante p. 322, 1. 55) and 35 unless it is used to shunt the receiving instrument. Mr. Swinburne has stated very fully and clearly in his evidence that the interchangeability of condensers and inductive coils had been for a long time a matter of common knowledge. Also Mr. Brown said they are interchangeable in his Provisional Specification p. 2, 11. 9-14 (ante p. 314, 11. 29 to 35). [Bousfield K.C.-He found that was wrong 40, and omitted it from the Complete Specification.] It is an admission, however, of what Mr. Swinburne proved was well known. Prof. Boys gave evidence to the same effect. Then there is the Williams coil. If Brown had specified that he had achieved, by a coil of a particular self-induction and low resistance, a new result not achieved by Williams, he might have patented that, but he merely says you 45 are to have high self-induction, and leaves the reader to invent. The same thing is disclosed in Varley's Specification (No. 3,453 of 1862) in the first mode on p. 6, 11. 6-13 (ante p. 325, 1. 44) and the 4th mode p. 8, 11. 1-17 (ante pp. 325-6). Mr. Swinburne's evidence is that what was really wanted was a large "time"constant," and Mr. Brown does not give that; he leaves the user to make ex- 50. periments with a perfectly old device so as to arrive at the form which is said to yield satisfactory results. Then as to Claim 4. It is bad because the directions include the use of what is useless (p. 3, 1. 40, ante p. 315, 1. 56 and p. 8, 1. 37, ante p. 322, 1. 34). It was clearly admitted by Mr. Brown that this will only work at all with an alternating current. The case is precisely analogous to that 55 of Badische Anilin und Soda Fabrik v. La Société Chimique des Usines du Rhône (15 R.P.C., 359, at pp. 365-6), in which the reader was directed in the 66 |