Patent – Validity – Disconformity between Provisional Specification and Complete Specification – Nature of Invention – Distinction between Patentable and Non-patentable Inventions – Patents, Designs, and Trade Marks Act, 1883 (46 & 47 Vict. c. 57) ss. 5 sub-s. 3, 26: LANE FOX v KENSINGTON AND KNIGHTSBRIDGE ELECTRIC LIGHTING COMPANY. [1890 L. 2713.] [COURT OF APPEAL]
LANE FOX v KENSINGTON AND KNIGHTSBRIDGE ELECTRIC LIGHTING COMPANY.
[1890 L. 2713.]
[COURT OF APPEAL]
 3 Ch 424
HEARING-DATES: 27, 28, 29, 30, June 2, 4, July 10 August 1892
10 August 1892
Patent – Validity – Disconformity between Provisional Specification and Complete Specification – Nature of Invention – Distinction between Patentable and Non-patentable Inventions – Patents, Designs, and Trade Marks Act, 1883 (46 & 47 Vict. c. 57) ss. 5 sub-s. 3, 26.
The Plaintiff, an electrician, took out, in 1878, a patent for “Improvements in obtaining light by Electricity, and in conveying, distributing, measuring, and regulating the electric current for the same, and in the means or appliances employed therein.” He subsequently disclaimed his claims in respect of measuring, conveying, distributing, and regulating by means of the electrometer, and only claimed in respect of an invention for keeping the electro-motive force of the electric current in the mains constant by means of the employment of Plant ‘s secondary batteries, in combination with dynamos, and in conjunction with a regulator.
In an action by the Plaintiff for infringement of his patent, it was held, by A. L. Smith, J., that the patent was bad, because (1.) the Plaintiff’s complete specification, as amended, did not describe the same invention as his provisional specification, (2.) the invention as described could not be made to work, and (3.) no sufficient information was given by the Plaintiff as to how it was to be made to work; but that if the Plaintiff had not failed in these respects the invention would have been good subject-matter for a patent, and had not been anticipated; and there would have been infringement by the Defendants:-
Upon appeal, it was held by the Court, in affirming the judgment of A. L. Smith, J., that the Plaintiff’s invention was novel; but that his patent, as amended, was invalid upon the grounds (1.) that the original patent was granted for an invention different from that for which he claimed protection after the disclaimers, (2.) that it was not, in 1878, useful for the main purpose for which it was designated, viz., the practical lighting of large districts, and (3.) that the specification was insufficient to enable an electrician, of ordinary competence and skill in 1878, to carry it out without further experiments and invention.
Per Lindley, L.J.:- An invention is not the same thing as a discovery; and if a man does nothing more than discover that a known machine can
produce effects which no one before him knew could be produced by it, his discovery, however great and useful, is not a patentable invention.
To entitle a patentee to maintain his patent, he must make some addition not only to knowledge but to previously known inventions; and must produce either a new and useful thing or result, or a new and useful method of producing an old thing or result.
The discovery that a known thing can be employed for a useful purpose for which it has never before been used is not alone a patentable invention; but the discovery how to use such a thing for such a purpose will be a patentable invention if there is novelty in the mode of using it as distinguished from novelty of purpose; or if any new modification of the thing, or any new appliance, is necessary for using it for its new purpose, and if such mode of user, or modification, or appliance involves any appreciable merit.
THIS was an appeal by the Plaintiff, from the decision of Mr. Justice A. L. Smith, sitting for Mr. Justice Romer n(1) , where the facts of the case and the arguments on either side are fully reported.
A cross notice of appeal was given by the Defendants.
Mr. St. George Lane Fox, the Appellant, in person, contended (inter alia) that in cases of alleged unworkability, it was usual to produce evidence of an attempt to work according to the specification which had resulted in failure; but that no such evidence had been produced with regard to his system.
He also contended that the fact that an invention is used for a purpose different from that for which it was used by the inventor does not prevent that use from being an infringement: Edison and Swan Electric Light Company v. Holland n(2) , Thomson v. Batty n(3) .
He referred also to Nuttall v. Hargreaves n(4) , and, with reference to the principles applicable to questions as to the utility of an invention, he cited Plimpton v. Malcolmson n(5) .
R. W. Wallace (with whom were Sir H. Davey, Q.C., and Finlay, Q.C.) was only called upon to address the Court upon the question whether the invention as patented would work; and did so accordingly.
n(1)  2 Ch. 66.
n(2) 5 Rep. Pat. Cas. 459, 482.
n(3) 6 Rep. Pat. Cas. 84, 99.
n(4) 8 Rep. Pat. Cas. 450;  1 Ch. 23.
n(5) 3 Ch. D. 531, 582.
Mr. Lane Fox, was heard in reply.
In other respects, the arguments were either substantially the same as those already reported in the Court below, or were of a character too technical for the purposes of this report.
1892. Aug. 10.
PANEL: LINDLEY, LOPES and KAY, L.JJ
JUDGMENTBY-1: LINDLEY, L.J
LINDLEY, L.J: :-
This is an appeal by the Plaintiff against a judgment of Lord Justice A. L. Smith, dismissing an action brought for the infringement by the Defendants of a patent belonging to the Plaintiff. As usual in such cases, the Defendants denied the infringement, and denied the validity of the Plaintiff’s patent, on the ordinary grounds of want of subject-matter, want of novelty, want of utility, insufficiency of the specification, and, in addition to these, the Defendants contended that the nature of the invention, as described in the provisional specification, was not the same as that described in the complete specification, at any rate after it had been amended and put into its present form. Lord Justice A. L. Smith decided in the Defendants’ favour on the last point; but he also came to the conclusion that the invention, as described, could not be usefully worked; and that the directions to work it were insufficient. He, however, decided the other points in favour of the Plaintiff, and held that, if the patent had been valid, the Defendants would have infringed it.
A cross notice of appeal was given by the Defendants, and the whole case was argued at great length before this Court by Mr. Lane Fox in person, on the one side, and by Mr. Wallace, as counsel for the Defendants, on the other. The Court was supplied with a printed copy of the shorthand writer’s notes of the evidence taken in the Court below, of the arguments of counsel on the trial of the action, and of the judgment of the learned Judge. All these I have carefully read and studied since the argument in this Court was closed.
The Plaintiff’s patent, as described in his original specification, was for “improvements in obtaining light by electricity, and in conveying, distributing, measuring, and regulating the electric current for the same, and in the means or appliances employed therein.” The provisional specification was filed on the 9th of
October, 1878, and the complete specification was filed on the 9th of April, 1879. Owing to subsequent disclaimers and amendments, which it will be necessary to examine more carefully by-and-by, the only part of the patent which has to be considered is that relating to the distribution and regulation of electric currents for purposes of lighting.
In order to understand the nature of the Plaintiff’s invention, and the objections taken to the validity of his patent, it is necessary to ascertain what was the state of knowledge as regards electric lighting in 1878. This is by no means an easy matter, for since that time much has been learned, vast improvements have been made, and the progress has been so fast, and yet so gradual and continuous, that there is great danger of supposing that what is plain and well known now was plain and well known then.
The evidence given in the case shews that the following matters were well known in 1878:- First, that electricity could be used for lighting purposes; second, that the are or brush light was known and in course of being perfected; third, that incandescent lighting was foreseen as possible and probable, and that many persons were trying to discover how to effect it; fourth, that electric generators, and what are now called dynamos, were well known; fifth, that Plant ‘s secondary batteries, capable of being charged by an electric current, and of storing electricity (i.e., of remaining inert, and of giving electricity out when wanted), were well known and had been used for arc lighting; sixth, that the voltage of the electric current given off by such batteries could be increased or diminished by adding or removing cells; seventh, that in order to obtain and maintain an electric current a complete conducting circuit was necessary; eighth, that for currents of low tension the earth itself might be used for a return conductor; ninth, that “earth,” or “an earth,” was a technical expression used to denote any suitable return conductor; and, tenth, that any competent electrician would know that, if in any particular case he could not use the earth itself as a return conductor, some other return conductor would have to be provided.
On the other hand, the evidence shews that in 1878 it was not
known how to construct an incandescent electric lamp for any generally useful purpose. It was not known to be important for the purpose of lighting with such lamps that the current supplying them should be kept at a constant pressure of about 100 volts; nor was it known that good results for incandescent electric lighting could be obtained by using secondary batteries, such as Plant ‘s, in conjunction with dynamos. Further, in 1878 dynamos did not work so smoothly as they do now, and some better method of regulating the action of the engines used to drive them was necessary, or at least desirable. Lastly, it was not known that, for lighting large districts with incandescent lamps with electrical currents of high tension, the earth could not be used as a return conductor.
Such being the state of knowledge in 1878, the Plaintiff claims by his patent to have done three things which were new and useful – viz. (1.), he claims to have invented a lamp which would answer the purpose; (2.), he claims to have invented a method of keeping the electro-motive power of the current in the mains constant at about 100 volts; (3.), he claims to have invented a method of better regulating the engines which drive the dynamos. The lamp has been since replaced by cheaper and better ones and has been disclaimed. The regulator has become unnecessary by reason of improvements in engines and dynamos, and has been disclaimed, but it was a very important part of the Plaintiff’s original invention.
There remains the invention for keeping the electro-motive force of the current in the mains constant.
This invention is the one which has to be considered in this action. An invention is not the same thing as a discovery. When Volta discovered the effect of an electric current from his battery on a frog’s leg he made a great discovery, but no patentable invention. Again, a man who discovers that a known machine can produce effects which no one before him knew could be produced by it, may make a great and useful discovery; but, if he does no more, his discovery is not a patentable invention: Britain v. Hirsch n(1) ; Harwood v. Great Northern Railway Company n(2) ; Horton v. Mabon n(3) ; Saxby v. Gloucester Waggon Company
n(1) 5 Rep. Pat. Cas. 226, 232.
n(2) 11 H. L. C. 654.
n(3) 12 C. B. (N.S.) 437.
n(1) . He has added nothing but knowledge to what previously existed. A patentee must do something more; he must make some addition, not only to knowledge, but to previously known inventions, and must so use his knowledge and ingenuity as to produce either a new and useful thing or result, or a new and useful method of producing an old thing or result.
On the one hand, the discovery that a known thing – such, for example, as a Plant battery – can be employed for a useful purpose for which it has never been used before is not alone a patentable invention; but, on the other hand, the discovery how to use such a thing for such a purpose will be a patentable invention if there is novelty in the mode of using it, as distinguished from novelty of purpose, or if any new modification of the thing, or any new appliance is necessary for using it for its new purpose, and if such mode of user, or modification, or appliance involves any appreciable merit. It is often extremely difficult to draw the line between patentable inventions and nonpatentable discoveries, but I have endeavoured to state the distinction as I understand it, and so far as is necessary for the purposes of the present case. I have, of course, been guided by the previous decisions on the subject, and especially by Harwood v. Great Northern Railway Company n(2) , which is the most instructive of them all.
I have been induced to make these observations in order to apply them to the question, whether the Plaintiff’s invention is anything more than a discovery that Plant ‘s cells can be usefully employed for incandescent lighting. If it is not, his invention will not be the subject-matter of a patent. What, then, is the nature of his invention as described in his original specifications? It certainly is not for the mere use of Plant batteries in connection with dynamos. It is for the use of them as described, which is a very different matter. [The Lord Justice then read the material portions of the provisional and complete specifications, and continued:-] I cannot read these specifications without coming to the conclusion that the Plaintiff thought he had discovered how to overcome one of the greatest difficulties in incandescent lighting. He points out that the electro-motive
n(1) 7 Q. B. D. 305.
n(2) 11 H. L. C. 654.
force of the electric conducting mains should be kept constant at about 100 volts by means of dynamos and secondary batteries, used as described at various places, and in conjunction with the regulator, which, he says, is necessary. That is his discovery and the nature of his invention, as stated by himself. It is not put in this simple form; it is mixed up with the mode of carrying the invention out. The Plaintiff not merely discovered that Plant ‘s secondary batteries could be usefully employed for incandescent lighting, but he shewed the importance of keeping the electro-motive force in the mains constant at the best voltage; and he claims to have shewn how, practically, the desired result could be obtained, which no one knew before. As regards the nature of the invention as originally described, and as regards its being the proper subject-matter for a patent, my decision is in favour of the patentee, provided always that his invention proves practicable. This accords with the view taken by Lord Justice A. L. Smith.
But this view of the Plaintiff’s invention is of no use to the Plaintiff; for neither the Defendants nor any one else use this invention as it was originally described. The Plaintiff now claims something very different, viz., the use of secondary batteries in conjunction with dynamos for the purpose of keeping the electro-motive force constant in the mains at about 100 volts. Lord Justice A. L. Smith held this to be an invention very different from that originally described, and he also held that if this was the Plaintiff’s invention it would not work without modifications and precautions which the Plaintiff never pointed out. I agree with him on both points, and I will take the last first. It is, I think, clear that no one had ever shewn or professed to shew how to produce this desired effect before 1878. Many prior patents were referred to by the counsel for the Defendants to shew want of novelty in the Plaintiff’s invention, but there is no trace in any of them of any method of keeping the electro-motive force in a main constant at any particular voltage, nor was that the object of any of them. I dismiss them all with that short observation.
I pass from the novelty to the utility of the alleged invention and to the sufficiency of the specification for carrying it out.
The utility of the alleged invention depends not on whether by following the directions in the complete specification all the results now necessary for commercial success can be obtained, but on whether by such directions the effects which the patentee professed to produce could be produced, and on the practical utility of those effects. Can it be said that the invention as described in the amended specification was in 1878 a practically useful addition to the then stock of inventions? To judge of utility the directions in the amended specification must be followed, and, if the result is that the object sought to be attained by the patentee can be attained and is practically useful at the time when the patent is granted, the test of utility is satisfied. Utility is often a question of degree, and always has reference to some object. Useful for what? is a question which must be always asked, and the answer must be, Useful for the purposes indicated by the patentee. See per Lord Chief Justice Tindal in Cornish v. Keene n(1) ; Edison and Swan Electric Light Company v. Holland n(2) ; Badische Anilin und Soda Fabrik v. Levinstein n(3) .
An invention may be useful as indicating the direction in which further progress is to be expected, and yet that same invention may be useless for any other purpose; useless that is, as an invention without further developments and improvements which have not occurred to the patentee. That is, in my opinion, the real truth with respect to the Plaintiff’s invention as now claimed by him. He made a distinct and important step in advance. The Plaintiff was the pioneer; he shewed others the road to be followed, but he did not give the traveller the information necessary to enable him to travel on it. There were difficulties to be overcome which the patentee did not foresee, and against which he naturally made no provision. There is an enormous mass of conflicting evidence upon the possibility of obtaining practically useful results by following the directions contained in his specification. Much of the evidence adduced against the patentee merely goes to shew that by following the directions in the specification you cannot produce such good
n(1) 1 Web. P. C. 507.
n(2) 6 Rep. Pat. Cas. 243.
n(3) 12 App. Cas. 712, 719, 720.
results as are produced by the Defendants. This, obviously, is wholly immaterial. But there is, besides, a great deal of evidence to shew that an electrician of ordinary skill could not have produced any useful result in 1878, if he simply followed the directions contained in the specification, as amended, with such variations only as an electrician of ordinary skill would have known how to make in 1878. So much more can be done now by a Plant battery than was suspected in 1878, that I have found the greatest difficulty in coming to a conclusion on this all-important question, and I much regret that we had not the assistance of an expert in electrical science. I have studied the whole evidence with all the care I can bestow upon it, and have come to the conclusion that the Plaintiff had not, in 1878, invented what he now says he had – viz., a practical method of keeping the electro-motive force in the mains constant at about 100 volts, by means of secondary batteries and dynamos used simultaneously as described.
The evidence adduced by the Plaintiff shews that something like his invention can be worked on a small scale, and to a limited extent, when it is not necessary to charge the mains so as to produce a high pressure when the lamps are connected with the main. professor Barrett’s evidence as to what he did in his own laboratory for six years shews this; and it must be borne in mind that for a time he used water pipes and the earth as a return conductor, and shewed them to be sufficient. But his voltage was low; his dynamo produced a current at a tension sufficient for his lamps, without the aid of secondary batteries, and he used his batteries as reservoirs rather than as regulators. Moreover, Professor Barrett did not produce these results earlier than six or seven years ago, when much more was known about what could be done with Plant batteries than was known in 1878. The other cases in which the Plaintiff endeavoured to prove that his invention had practically succeeded will be found to have involved considerable important departures from his invention as described. The installation for Lady Conyers’ ball is the best case the Plaintiff has; but there the batteries were taken charged, which is a very important matter.
The Defendants have, in my opinion, succeeded in proving
that the lamps will be destroyed, if, whilst they are connected with the main, the batteries are charged at a sufficient voltage to work for any useful purpose. This objection to the patent goes to the root of the Plaintiff’s alleged invention. The objection is said by the Plaintiff to be based upon the erroneous assumption that the batteries must be charged and emptied to an extreme extent. “Charging” and “discharging” are, no doubt, relative terms, to be understood within reasonable limits, and a workman, intelligent enough to seize the idea of the patentee, would perhaps know, in a general way, that the electro-motive force could be regulated and kept approximately constant without excessive charging or discharging, and the brightness or dimness of the lamps would be his guide. But, conceding this, I think it proved that high charging is necessary to keep the electro-motive force constant at anything like 100 volts; and, if such high charging is necessary, it is not disputed that the lamps will be destroyed if the batteries are charged when the lamps are on, unless precautions against this cause of failure are taken. None, however, are indicated in the specification. I think it proved that a small variation in pressure in the main will cause a current to go into, or come out of, the secondary battery for a very short time. But this is not enough for practical purposes. High charging being necessary, it is, in my opinion, proved that the Plaintiff’s invention will not work without switches; and these are not mentioned in the specification.
Upon this point there is much conflicting evidence, attributable, in great part at all events, to the ambiguity of the term “switching.” It was known, before Plant invented his secondary batteries, that the voltage of primary batteries could be increased or diminished by increasing or diminishing the number of cells. The mechanical means of doing this is called “switching,” and Plant himself pointed out that the voltage of his secondary batteries could be increased or diminished by similar means. Regulation, to some extent, takes place without switches. It is admitted by the Defendants’ own witnesses that the batteries have a steadying effect for a short time; that they act as regulators to some small extent; and Professor Barrett has produced satisfactory results in his laboratory with
low voltage without switches. In Lady Conyers’ case there were no switches, but there was no dynamo at work. On the other hand, the evidence convinces me, that, for practical lighting with an electro-motive force of about 100 volts, and with dynamos and batteries and lamps all in use, switching is essential, and that no ordinarily competent electrician would have known, in 1878, how to keep the electro-motive force in mains constant at about 100 volts, without further instructions than the Plaintiff gave him. The Plaintiff’s claim to have invented, in 1878, a practically useful method of keeping the electromotive force in the mains constant at about 100 volts whilst the dynamos are running and the batteries are being charged and the lamps are on, cannot, in my opinion, be sustained. This is the broad ground on which the patent, as amended, must be held invalid, and this was the ground on which Lord Justice A. L. Smith condemned it on its merits.
Having arrived at this conclusion, it is unnecessary to consider the objections taken to the specification on the ground that the directions about the earth were misleading; and that the direction that the cells of the batteries should have very large conducting plates was too indefinite.
I have hitherto made no allusion to the Plaintiff’s regulator, but this was, in my opinion, an essential part of his original invention. He says in his original specifications that it is necessary. Necessary for what? The context shews that it was necessary to keep the electro-motive force in the mains constant. This was a mistake, and the regulator, and all that was said about it, has been disclaimed and struck out by amendment. But the effect of this is entirely to change the nature of the invention as described in 1878, and to enlarge it, which is not permissible. (See In re Gaulard and Gibbs’ Patent n(1) .) In the original specification the Plaintiff drew a marked distinction between storing and regulating; the secondary batteries were for storing, the regulator was for regulating. It is true that storing involves of necessity a certain amount of regulation; but over and above such regulation as is necessarily incidental to storing, further regulation was said by the inventor in 1878 to be necessary for
n(1) 6 Rep. Pat. Cas. 215.
his invention. Between 1878 and 1883 he discovered that the regulator was not wanted, and that everything could be done by secondary batteries, as used in 1883, by which time dynamos and switching had been greatly improved. He accordingly disclaimed the regulator. I am satisfied that the Plaintiff had no idea that he could do without the regulator when he obtained his patent. He learnt it afterwards; and by disclaiming the regulator and amending his specification in 1883, as he did, the Plaintiff essentially changed the nature of his invention for keeping the electro-motive force in the mains constant. The claim to the use of the batteries as reservoirs had a definite meaning in the original specification, but it has a different and much wider meaning in the specification as amended in 1883. The Plaintiff is now really claiming a patent for the mere use of Plant ‘s batteries in conjunction with dynamos. Such a patent would not have been valid unless the patentee had done something more. He must have shewn how the two were to be successfully worked together. But, assuming that a patent for such an invention might have been obtained, the Plaintiff’s patent was not granted for any such invention. The effect, therefore, of the disclaimer and amendment made in 1883 has been to destroy the validity of the Plaintiff’s patent, if it ever could have been made to work. Upon this point again I agree with Lord Justice A. L. Smith.
It is needless to consider the question of infringement. I will only add that, if the Plaintiff’s patent could be upheld as a patent for the use of secondary batteries in combination with dynamos, then the Defendants would obviously have infringed his patent. But unless his patent can be upheld to this extent, no infringement has taken place.
Convinced, as I am, that the Plaintiff made a great step in advance when he suggested the application of Plant ‘s batteries, for the purposes of incandescent electric lighting, I feel bound to hold his patent invalid, on the ground that it was granted for an invention very different from that which he now claims to have protected, and on the ground that it was not in 1878 useful for the main purpose for which it was intended – viz., the practical lighting of large districts, and upon the ground that
his specification was insufficient to enable an electrician of ordinary competence and skill in 1878 to carry it out without further experiments and invention, as distinguished from mere practice and increased dexterity and skill. The appeal, therefore, must be dismissed with costs, in the usual way.
JUDGMENTBY-2: LOPES, L.J
LOPES, L.J: :-
I agree, and have nothing to add.
JUDGMENTBY-3: KAY, L.J
KAY, L.J: :-
This action is brought to restrain infringement of the Plaintiff’s patent, and for an account of profits or damages.
The patent is dated 1878, and has been amended by two disclaimers in 1882 and 1883.
The case is one of some difficulty, and the difficulty arises in great measure from the fact that the patent relates to electric lighting by incandescence, and in 1878 no practical mode of doing this had been perfected. Mr. Lane Fox contemplated lamps in which the incandescent material was platinum or iridium, which was to be maintained at a luminous heat not in vacuo. The incandescent lamp now in use, in which the material is carbon enclosed in a glass bulb exhausted of air, was not brought into practical use until some years after Mr. Edison’spatent in 1881.
The real object of this action is to claim the exclusive right to the use of what are called accumulators in the modern system of electric lighting. I understand that accumulators are, in fact, what were originally called secondary batteries. They were invented or improved by Plant , and, at the time of this patent, were known as Plant batteries. They are not batteries for the original generation of electricity, but, if I rightly understand the evidence, they are constructed of plates of lead partly immersed in dilute sulphuric acid, the alternate ones connected with the positive and negative poles of the battery, and in the circuit with a dynamo or other generator of an electric current. When electricity is, by the action of such generator passed through the battery, an alteration takes place in the lead plates by the
deposit upon their surfaces of peroxide of lead. When the generator ceases to act, if the circuit is continued, there is a re-solution of that peroxide, and the battery during that chemical process gives out a considerable quantity of electricity. Directly the generator ceases to act, however, the electro-motive force – called otherwise the voltage, or potential – lowers, at first rapidly, and then much more slowly, and the current is maintained at this lower voltage for a considerable period, varying, of course, with the size of the plates in the battery and the quantity in comparison of the charge.
All this was known before the Plaintiff’s patent; and Plant ‘sbatteries are accurately mentioned in his provisional specification as “reservoirs” of electricity. The provisional specification does not indicate distinctly that they were intended in his combination to answer any other purpose.
The combination which he claims that the Defendants are infringing consisted of several elements: (1.) A number of incandescent lamps arranged, not in series, but what is very inartificially called “in parallel,” i.e., through each of which passes, not the whole current carried by the main wire, but a portion only drawn from the main wire by a small wire serving the lamp from which it is returned also by a separate return wire. (2.) The introduction into this system of several Plant ‘s batteries joined in like manner to the main wire at different points, and each having a separate junction with the return.
The complete specification contains this sentence: “In order to keep the electro-motive force in the electric mains constant it is desirable to have, in the first place, several generating machines, also a number of reservoir batteries as before explained.” In the provisional specification the last clause of that sentence – “also a number of reservoir batteries, as before explained” – did not occur. Instead, the sentence ran thus: “next it is necessary to have some regulator such as that about to be described.” The regulator was an electrometer, the needle of which oscillated between two metal points. When the voltage was too high it touched one, and completed a circuit which actuated a lever so as to shut off steam, and thus diminish the speed of the dynamo.
When the voltage got too low the needle, deflecting in the opposite direction, touched another metal point, which produced the contrary effect and quickened the motion of the dynamo. This regulator is struck out by disclaimer, and now in the altered specification the only regulation is keeping the electro-motive force in the mains constant, which is to be done by (1.) several generating machines, and (2.) a number of reservoir batteries. I find it impossible to make the provisional and complete specifications consistent in this respect. The provisional describes the mode of keeping the electro-motive force constant: (1.) several generating machines, and (2.) the electrometer regulator. It does not mention the secondary batteries as useful for that purpose, but as reservoirs only. Mr. Lane Fox argued before us that their purpose was to act as a sort of buffer, to use the expression he frequently employed, and, accepting an illustration suggested by the Bench, he said their office was something like that of the air vessel in a force pump which corrects the pulsation of the pump, and causes the water to be delivered in a continuous stream. I am satisfied by the evidence that this would not be the effect of the secondary batteries, if employed as described by his patent. He directs them to be charged from the dynamo while some lamps are in the circuit. Taking the voltage requisite for the lamps at 100, I think it is proved that the batteries, at least, with any reasonable size of lead plate, could not be charged so as to be useful for this purpose with a current of less than 115 to 125 volts, which would destroy the lamps in a short time. Even if properly charged they could not practically be used to keep up the current when the dynamo was not running, without an arrangement by which the number of battery cells in communication with the main wire could be altered from time to time by a system of switches. If the use of the batteries was to keep the electro-motive force constant in the main wires there are two objections to this patent, each of which seems to me formidable. First, this is not contemplated by the provisional specification, which describes a different mode of effecting that purpose, and therefore differs essentially from the complete specification; and, secondly, the mode of using the batteries described in the complete specification of this patent would not
produce the effect of keeping the electro-motive force constant in the main wire.
The use of these batteries as reservoirs of electricity was merely using them for the purpose for which they were invented by Plant , and a patent for putting such reservoirs in connection with the main wires in a system of electric lighting involves no invention whatever, any more than using water reservoirs in connection with pipes supplying a city with water.
By disclaimer the Plaintiff has struck out from his specification the regulation by the electrometer. As I read the provisional specification, this, and the employment of several generating machines was the only mode of regulation which the patentee originally contemplated. But I think by regulation, he did mean keeping the electro-motive force as nearly as possible constant in the main wires. The disclaimer has struck out one device for effecting this, which is said, both in the provisional and complete specification, to be “necessary,” and it may be a question whether this is not an alteration of the invention which makes the combination now claimed, essentially different.
But the most serious objection, in the view of this patent which I take, is that it is a crude description of an invention which, as described, had no practical utility. None of the elements of the combination was new in itself. I am satisfied, as I have said, that the combination, as described by the patentee, could not be efficiently worked without at least two essential alterations. One, that the secondary batteries must be charged when the lamps were not in the circuit with a current of electricity of a voltage which the lamps would not bear, and, secondly, that these batteries would be practically useless unless they were worked with switches as I have before mentioned. Without such an arrangement they could not be made to keep the electro-motive force constant in the main wires. The automatic action which Lane Fox supposes would accomplish this is, I am persuaded, a mere delusion. These two essential alterations were necessary to make accumulators of use. Neither of them is contemplated by Lane Fox. Assuming that he was the first to suggest the placing of
reservoir batteries in communication with the main wires in a system of electric lighting by branches from the main, his mode of doing this was practically useless; and, for this reason, I agree with the result at which the learned Judge has arrived. I think the patent is invalid and that this appeal should be dismissed.
Solicitors: Vandercrom, Hardy, Oatway & Doulton; Deacon Gibson & Medcalf.
W. W. K.
(c)2001 The Incorporated Council of Law Reporting for England & Wales