the oxygen of the ore, on the other: as, for example, in the smelting of iron, the ore, which in this case is always an oxide of iron, is introduced into a furnace where it comes in contact with hot carbon, which removes the carbon chemically by combining with it and setting the iron free. 'Smelting,' then, may be said generally to indicate the melting of something by heat, accompanied by a chemical change induced by the substances present in contact with the ore. The two exceptions just alluded to in this definition areFirst, the case of bismuth, in which the bismuth exists in a metallic condition; and, secondly, the Lake Superior ores of copper, where the copper also exists in a metallic condition. In both of these instances it is sufficient merely to raise these ores to a temperature sufficient to melt the contained metal, and chemical action is not, therefore, necessarily present, but, even in these cases, chemical action is resorted to practically to render the earthy materials of the ore fusible, and thus render the separation of the metal more perfect. The substance added to bring about a chemical change in the earthy matters of the ore are called 'fluxes,' and they generally consist of limestone or of limestone and clay, so that, in the practical sense of the word, one may say the term 'smelting' always involves melting by heat and the concomitant presence of a chemical change."

On cross-examination, Prof. Morton was asked this question: "Can you refer me to any instance of the use of the word 'smelt' or 'smelting' to signify the decomposition of a compound by the action of the electric current by any writer of recognized accuracy or authority? Ans. Not without the addition of the word 'electric.' As far as I am aware, the use of this compound word was first introduced into literature by the Messrs. Cowles in connection with their process, in which they described the operation which took place as electric smelting."

The first application of the Cowles brothers was filed December 24, 1884, and the patent was issued in June, 1885. This described the process, and was termed the "Process of Smelting Ore by the Current." On February 24, 1885, their second application was made for the apparatus by which this process might be successfully and commercially carried on. This was termed "An Electric Smelting Furnace." The most general claim describing the process in the first patent was as follows:

"The method of smelting or reducing ores or metalliferous compounds herein described, which consists in subjecting the ore in the presence of a reducing agent to the action of heat generated by passing an electric current through a body of broken or pulverized resistance material that forms a continuous part of the electric circuit, the ore being in contact with the broken or pulverized resistance material, whereby the ore is reduced by the combined action of the reducing agent and of the heat generated solely by the resistance of the broken or pulverized body through its mass."

It seems clear to me that the reason why the Cowles brothers called this an "electric smelting process" was because its main feature was like that of any smelting process as ordinarily understood, namely, the use of high heat and a chemical reducing agent, and because the heat was produced by electricity. The use of the carbon to attract the oxygen of the fused ore by chemical affinity most naturally suggested the smelting of iron and other metals by the same reagent. Before that time ores had been fused, and then subjected to electrolysis. If "smelting" meant only "melting apart," then this was smelting by means of electricity, but it was never so called. Even the Siemens arc furnace of 1877 was not described as an electric smelting furnace. It remained for the Cowles brothers to invent

the term to distinguish their discovery, and we may gain some idea of the sense in which they used it at the time of the assignment by reference to their idea of what their discovery was. Its important and main features, in their judgment, were the intense heat of the current made available by distributed carbon and the chemical reaction caused by the same agent. The many articles written by the Cowles brothers, and by disinterested scientists, together with the evidence of Alfred Cowles in an interference proceeding between the Cowles application and that of one Faure, are all quite convincing that, in 1885, they thought that, though electrolysis might play some part in the process, the main success of it was due to the smelting effect of the high heat, and the chemical reaction between the carbon and the nonmetallic element of the ores, and that a process which was purely and solely electrolytic was not embraced within the meaning of the term "electric smelting process" as they used it. This conclusion is still further borne out by the circumstance, already commented on, that though the parties to the contract of 1885 had before them and under discussion this very Bradley process, so described as to bring it clearly within the definition of "electric smelting" now contended for by the defendant and given by its witnesses, yet no specific words were used in the contract either to include the process in, or exclude it from, the operation of the assignment as would have been most natural, had the process been an electric smelting process, as it was then understood by the parties. There can be no doubt either of the distinction which the assignors in the assignment made between such a smelting process and one of electrolysis, for in the very application which the Cowles Company bought by this assignment of May 8, 1885, Bradley and Crocker distinguished the Bradley process of 1883 from the equivalent of the Cowles process, as follows:

"The present invention (1. e. their carbon smelting process) resembles the above (i. e. the Bradley process of 1883) to a certain extent; but in the present invention the electric current which we employ performs no electrolytic action, the reaction which takes place being purely chemical, and the function of the current being solely to develop the heat which is a necessary condition of the reaction. For this reason our invention does not require the use of a continuous current of electricity. An alternating current may be employed if desired, which is an advantage, since large alternating current dynamos may be constructed more cheaply than the continuous current machines, and it is also less trouble and expense to return them."

The Cowles Company took this application, and pressed it to a patent, which was issued to it as assignees, and, though the claim for the fundamental process was waived, that for an improvement thereon was retained, and the foregoing explicit declaration of a radical distinction between the carbon electric smelting process and the Bradley electrolytic process still appears in the specifications of the patent, and is, in effect, a formal admission by the Cowles Company, without which it may be presumed the patent would not have issued to it. From the whole record, I feel sure that the parties to the assignment of 1885 did not use the term "electric smelting processes" in the wide sense claimed on defendant's behalf, and that, in their minds, processes solely electrolytic were not embraced within

it. Therefore the Bradley process of 1883 was not conveyed to the Cowles Company by the assignment, and it never acquired title.

But suppose that I am wrong in thus limiting the meaning of the words "electric smelting process," and that even in 1885 it did include any process in which by the use of the current ores were melted and separated, even if there was no chemical reaction at all. The discoveries, patents, applications, and caveats relating to electric smelting processes and furnaces assigned by Bradley and Crocker are only those "which do or may interfere with❞ the Cowles patents. It has been pressed upon the court that these words modify only the phrase immediately preceding, namely, "caveats on file,” etc., and do not qualify the terms "discoveries," "patents," and "applications." This is much too narrow a construction. The Cowles Company was buying peace, and the clause in question was expressive of the intention which pervaded the entire document, and should be given its effect in construing every sentence and clause in it. We have found that neither of the parties thought that the Bradley process of 1883 was included in the assignment. We are now considering the question whether the general language of the assignment describing a class carried the process in spite of this common view of the parties. Certainly the court will lean to the construction of the general language used which may be reconciled with the common thought of the parties as to the particular process, and if, therefore, as I shall attempt to show, the construction, by which the discoveries, patents, and applications assigned are limited to those which did or might interfere with the Cowles patents, excludes from the grant the Bradley process of 1883, then it is the court's duty to place that construction upon the assignment. Moreover, the reference of the clause, "which do or may interfere," to all preceding subjects of the assignment, is a reasonable and grammatical interpretation of the language, for the relative pronoun "which" often has more than one antecedent, and there would seem to be no reason for thus limiting the caveats assigned without also limiting the more important words, "discoveries, patents, and applications." The words, "do or may interfere," are plainly to be construed with reference to the atmosphere in which the parties then were. They were in the atmosphere of the patent office. They were considering the question of applications, caveats, and patents,-all technical terms to describe different steps in the securing of a monopoly by government grant. The word "interfere" has a technical meaning in that connection. It is used in the statutes of the United States. Strictly speaking, an interference is declared to exist by the patent office whenever it is decided by the properly constituted authority in that bureau that two pending applications, or that a patent and a pending application, in their claims or essence cover the same discovery or invention, so as to require an investigation into the question of the priority of invention between the two applications or the application and the patent.

In the strictest technical sense, therefore, the fact that the Bradley application of 1883 was not declared to be an interference with

any of the Cowles patents, and that the Cowles patents were is sued, and as issued were not modified or affected, by the Bradley application of 1883, would exclude the Bradley application from the effect of the assignment. But it may be conceded that this is too strict an interpretation, and does not square with what appears to have been the manifest intention of the Cowles Company in securing this assignment. The interference referred to was either a declared interference in the patent office, or the total defeat or the narrowing of any of the otherwise valid claims of the Cowles patents, after issuance, in a court of competent jurisdiction, by the use of an application or invention of Bradley and Crocker or either of them. If, therefore, it appears that the otherwise valid claims of the Cowles patents are not narrowed or defeated by the specifications of the Bradley patents which are the subject of this litigation, then the Bradley patents did not pass by the assignment. The question is not to be determined by what the Cowles brothers may have claimed in any application, nor by what might have been claimed under their specifications and drawings, had Bradley never made his invention or application in 1883. It is whether the claims allowed to the Cowles brothers by the patent office are restricted or invalidated by the really new inventions of Bradley, as disclosed by his application of 1883.

If the patent office allowed Bradley any claims which the history of the art shows he should not have been allowed, then those claims can play no part in this discussion. If invalid, they are invalid because anticipated by some other patent, or by the discoveries in the prior art, and it certainly cannot be held that claims thus narrowed or defeated interfere, in the sense of the contract, with any of the otherwise valid claims of the Cowles patents. The questions remaining, therefore, for consideration, are: (1) What was the real invention of the Bradley patents? and (2) what are the valid claims of the Cowles patents, excluding consideration of the Bradley patent? and (3) are they interfered with by Bradley's discovery of 1883?

For eight years, from 1883 to 1891, the claims of the Bradley patent were rejected by the patent office, the examiners ruling that the use of a current of electricity to fuse a metallic compound, and to maintain the fusion, and to electrolyze the fused compound, was old in the art, because Sir Humphrey Davy had reported, as a contribution to science, his use of the electric current first to fuse, and then to electrolyze, potash and soda, securing a deposit at the cathode of the metal potassium and the metal sodium, respectively. In the collected works of Sir Humphrey Davy, reported in 1840, occurs this statement:

"I tried several experiments on the electrization of potash rendered fluid by heat, with the hopes of being able to collect the combustible matter, but without success; and I only attained my object by employing electricity as the common agent for fusion and decomposition. Though potash, perfectly dried by ignition, is a nonconductor, yet it is rendered a conductor by a very slight addition of moisture, which does not perceptibly destroy its aggregation, and in this state it readily fuses and decomposes by strong electrical powers."

Sir Humphrey Davy also tried the experiment with alumina or other refractory ores or oxides, and did not succeed in fusing them, because the current would not pass through them in their dry state. It was known that these ores, if fused, could be subjected to the electrolytic action of the current, but it seems never to have occurred to any one but Bradley how the current might be used to effect the fusion of the metal in its nonconducting state, as part of the electrolytic process. He secured it by putting the anode and cathode so close together that an electric arc was formed by the passage of the current through the air. This, as was well known, produced the highest possible heat, and quickly fused the ore between or near the anode and the cathode. The power of fused ore thus produced became at once a medium for the conduction of the current. Thereafter the resistance to the current in the fused ore caused heat, which could be easily increased to effect the progressive melting of the rest of the ore, by adding to the voltage or intensity of the current.

The history of the Bradley patent shows, as disclosed above, in the statement of facts, that Bradley attempted to secure the allowance by the patent office of one claim or more for the process of maintaining fusion and electrolysis by the electric current simultaneously in the treatment of metallic compounds. But it will be observed that even on appeal, and by the decision of the board of review in the patent office, his claims in this regard were very much narrowed. He was required by the board of appeal to make, as an essential part of the process described in his specifications and claims, the initial fusing of the metal as therein set forth, and, as the only initial fusing suggested was that described in the patent to be by the electric arc, it became an essential part of the process patented.

The acceptance by the patentee after he had made the claim for merely maintaining the fusion, and simultaneously electrolyzing the fused mass, and it had been rejected, estopped him from ever afterwards asserting monopoly to such a process, when the initial fusion described in his patent was not included in it, and showed with reasonable certainty that he was entitled to nothing more. Bradley's discovery, therefore, was of a combination of steps, each one of which was old. The steps were, first, the initial fusion by the electric arc between the carbon anode and cathode. The electric arc was certainly old. Second, the maintenance of the fusion by the heat of resistance to the current in the fused ore, and the consequent progressive melting of the rest of the ore. This step was plainly shown by Sir Humphrey Davy. And, third, electrolysis by the current, which was equally well known. Whether Bradley is really entitled to the monopoly of this combination or not may be questioned when the validity of his process is directly in issue. Both parties to this cause, in contending for the possession of it, have a motive not to diminish its scope more than is absolutely necessary to the establishment of his or its title, but sufficient appears in the record to justify the limitation of it as above. The other patent of