I concur in the opinion just delivered by the circuit judge. The reissued patent, No. 3,841, is not for the same invention as patent No. 37,317, and is consequently void. In addition to the summary of reasons just announced for the conclusion reached, it seems advisable to state that the original patent was merely for an improved method of bolting in the manner described, whereby an increased quantity of choice flour could be obtained from the ordinary process of milling, without any reference to purified middlings, by combined blowing and screening in an intermediate or another stage of the operations.
The original contract of Cochrane, in I860, with Warder & Barnett, shows that his purpose was, by low grinding, to produce a superior grade of flour in larger quantities than, heretofore known. He agreed to make “the most superior grade of flour in the United States out of four bushels and twelve pounds of choice wheat for each barrel of flour,” which result could not be accomplished except by low grinding, if at all. His scheme or plan did not contemplate a large amount of middlings, and could not have done so, for the lower the grinding the less the quantity, and, as a general rule, the poorer the quality, of the middlings.
At the time said contract was made, Coch-rane had an interest in the Coggswell & Mc-Kieraan patent, the devices of which he evidently designed to utilize. , His experiments at Lagonda, and subsequently at the first Barnett mill, also show thankis purpose was to produce a large amountNff such choice flour by low grinding from the least possible, or a comparatively small,) quantity of wheat.
The early experiments were directed to-that end, and hence the satisfaction evinced when the required amount' of flour was pro duced approximately from the designated amount of wheat. When, however, it was ascertained that no grade of good middlings flour could be thus made, the resort was had to higher grinding, of which, as to the result, Warder & Barnett complained as being one-quarter too much.
They prove by their correspondence at the time, just as the original patent shows, that the inventor supposed that by his process and devices for bolting he could accomplish his purpose by using the ordinary process of milling. This is evident, not only from the correspondence at the time, but from the mechanical inventions to which he referred, and also from the special stress placed on meshes of increasing fineness. In that correspondence there was a constant boast of the new mode of bolting, whereby the meshes were to be kept cool, and free from clogging, etc., and also of the device for returning the current of air through the cupola back into the reels, whence it had just escaped through the perforated pipes, meshes, etc. In one of the letters it was confidently claimed that the difficulties as to low grinding, even of spring wheat, could be overcome by Cochrane’s contrivances — that grinding of even that class of wheat could not be so low as to prevent “cleaning up.” It was low grinding, then, whereby the large quantity of choice flour-was to be made, that the inventor had in view. This was to be effected, not by an “intermediate” stage of purification uetween the production of superfine flour and the regrinding of middlings, but by the use oi *681meshes óf increasing fineness in the flour holts, assisted by blasts of air. Those blasts of air were to spend their force within the first three reels; for no- blasts were to be used in the separator before regrinding. The necessary effect of using successively finer meshes, instead of successively coarser, was to prevent the escape through the meshes of a larger quantity of impurities, and, con sequently, of making the flour thus screened clearer and better. The impurities thus prevented from passing through the screens into the flour would necessarily be retained in the reels, and pass off with the tailings, consisting of middlings, shipstuff, etc. It is not to be supposed that meshes of increasing fineness could operate in any other way. Hence the Cochrane process was not to purify the middlings, or increase their quantity or quality, but merely by his “improved method of bolting” to obtain a larger amount of choice flour from the specified quantity of wheat.
In his original patent, Mo. 37,317, he formulated four claims, not one of which was for purifying middlings, but two were specially directed to his mode of “bolting.”' He especially stated that the flour screened through each of his first three reels could be kept separate or mixed, as the miller might desire, without a hint that the siftings of the third reel would consist of dirty flour, or pulverulent impurities, not fit to be used, or which it was sought to remove, either from the flour thus sifted through the third reel or from the middlings within that reel, which were to pass off with the tailings.
The devices specified in the original patent are very significant on this point They provided for the introduction of a blast of air through perforated pipes into each reel, as stated, for the purpose of keeping the meshes open, cooling, etc., without mentioning any effect to be produced towards removing pulverulent impurities, or even naming such impurities. Indeed, if that effect had been contemplated, the invention would not Have provided a cupola with two screens and brushes to arrest-the escape of whatever was blown or wafted into the cupola, and to cause that wafted matter to be thrown bade or discharged directly into the first flour chest. If that wafted matter, whether flour, dust, or pulverulent impurities, was to be thus returned and mixed with the siftings of the first reel, it is evident that the invention had no reference to the removal and separation of such matter from the flour. Tlie devices involved necessarily a contrivance for the escape of the air forced into the reels — for an enforced current of the kind must have an outlet, otherwise disastrous results would follow, or the blasts cease to be operative. The screens in the cupola, and the brushes, for the purpose of returning the arrested partides into the reel-chest, indicate plainly enough that there was no thought of causing pulverulent impurities to escape through the cupola. This is made still more apparent from the fact that whatever escaped through the cupola was, in the normal operation of the connecting tubes, to be blown back into the very reels from which it had been just expelled. It was only in exceptional states of the weather that the valve in the tube was to be opened, but at all other times there was to be a return of the current escaping from the cupola into the reels, carrying with said current whatever it contained. If, then, the purpose was to expel impurities, why such well-arranged devices to force them back into the contents of the reels?
Again, the “cant” ventilator of Coggswell & MeKiernan, and their air blasts through zinc jackets, had been used at Lagonda and in the Barnett mill before the original patent, No. 37,317, issued, and Simultaneously with that patent Cochrane had procured for his “cant” ventilator his patent No. 37,321; yet in the specifications and claims of No. 37,317 he omitted, and it must have been ex industria, all reference to his No. 37,321, and substituted therefor his cupola, with screens and brushes. When he had ascertained, in 1874, that his devices, as referred to in the original patent, would not purify middlings, nor essentially aid in so doing, he interjected into his specifications for a reissue the rejected device No. 37,321. The testimony sufficiently explains why, from his experimenting at Lagonda and the first Barnett mill, he discarded the "cant” ventilation, independent of its anticipation by Coggswell & MeKiernan. The devices by which the improved method of bolting was to be carried on, so far as air was concerned, looked to an enforced current, or blast, operating from -within the reels outward, and not by induced currents operating from without, through the screens, inward or upward, as in flat and vibrating sieves.
Whatever construction may be properly put on the words “combined operations of screening and blowing,” it is obvious that the original invention contemplated a blast of air from within the reels, whereby its force should be directed not only through the meal as it was whirled around inside the reels, but also against the meshes of the reels, tending to force through whatever was small enough to pass. If the flour dust was thus forced through and wafted into the cupola, while the heavier particles — small enough to pass — fell by their greater specific gravity into the conveyers, the extremely comminuted particles of the integuments of the wheat berry, or of its cell-walls, would, like the flour dust, pass into the cupola by force of the blast, there to be arrested and brushed back into the flour, or returned through the tube into the reels, to be again and again whirled in and out in a continuous round.
' The many changes made by Cochrane, and Warder & Barnett, after the original patent *682Issued, and also alter the reissued patent was granted, in order to adjust tlie devices referred to in No. 37,".17 to an induced current or suction, indicate very clearly that the idea or thought of a process for purifying middlings in an “intermediate” or any •other stage of the manufacture, by the combined operations of blowing and screening, was not originally in the mind of the inventor. The testimony is clear that when the Cochrane device or machine was rearranged and altered so as to work by suction, the perforated pipes performed no function. The manner of inducing or drawing the air into the reel-chests by suction, and the ■operation of the reel-screens when suction was used, were the reverse of combined blowing and screening. It cannot be fairly said, in the light of facts and circumstances now in evidence, that those reverse modes •of operating were substantially the same, or immaterial changes as to form or modes of •accomplishing what the patent covered. Even after the reissue, No. 5,841, Cochrane and Warder & Barnett had to resort to important changes as to the modes of introducing air into their reel-chests; they abandoned the device of a cupola with screens and brushes, introduced practically a new tube and valve, left their perforated pipes functionless, and changed blasts into suctions, •or enforced- into induced currents. In brief, the essential changes in Cochrane’s devices, ■as described in No. 37,317, which he was compelled to make in order that a beneficial result might follow, so far as purifying mid-dlings went, demonstrate that a process for purifying middlings and making therefrom a high grade of flour, superior to superfine, was not thought of by him in or before 1863.
But where can there be detected in No. 37,317 a suggestion either of a mode of purifying middlings by the combined operations of blowing and screening, or of an “intermediate” stage therefor between the production of superfine flour and the regrinding •of the middlings? Where is or was such an ■“intermediate” stage? It is contended that •the screenings by the first reel were superfine flour, or, if not, perhaps the screenings •also of a part or whole of the second reel, and, consequently, the combined operations of blowing and screening in the third reel purified the middlings at that stage which was intermediate the production of superfine flour and the regrinding of the middlings. But we have endeavored to show that the screenings of the third reel were flour, which could be mixed with the flour from the first two reels, and that the patent so states. If, then, by meshes of increasing fineness, the middlings discharged at the tail of the third reel were less free from impurities than they would be if coarser meshes were used, the process of purification could not occur by the use of that reel, nor at that stage of the operations. There is suggested in the original patent neither the idea of purifying the middlings at the intermediate stage mentioned, nor the use of the combined operations of screening and blowing for that specific purpose. It cannot be said that the mention of “white middlings” embodies such a conception, so that the reissue, without expansion, could cover the purification of mid-dlings in the manner and at the stage claimed, for the term “white middlings” was well known to the art of milling long before, and also to the commercial world. The manner in which “white middlings” are referred to in the patent shows that the term was used as one well known, and not as a new or special product of any superior value.
A comparison of the original and reissued patents, and an examination of Cochrane's contract with Warder & Barnett in 1860, also of the correspondence of the latter and of the testimony concerning low and high grinding in connection with Cochrane’s invention, will show that the purpose was as stated, viz., by the ordinary process of milling, through his method of bolting, to increase the yield of choice flour. He soon learned that higher grinding, or what Profess- or ílorsford’s report terms “half-high milling,” was necessary to the production of the best quality of flour, or of that superior grade which he contracted to make. Instead of accomplishing the promised result by low grinding from four bushels and twelve pounds of wheat, higher grinding was soon resorted to, requiring five bushels and twenty pounds of wheat per barrel. He complained to his millers, it is said, that they persisted in 'grinding too low, although that mode of grinding was necessary to make the required yield, and insisted that they should grind higher. It was well known in the art that high grinding made a better quality but less quantity of good flour, but Cochrane thought he could increase the quantity of choice flour by his process. Warder & Barnett, it seems, following, it may be, the suggestion of Cochrane, began the use of high grinding at an early day, and stated to their correspondents that certain shipments made were from grinding “high,” yet, in one of their letters, they then boasted that by the new method even spring wheat could not be ground “too low” to prevent its being “cleared up.” The ordinary process of milling, in connection with which Cochrane’s method of bolting was to be employed, must have been, if not low grinding, certainly not the high grinding used in defendant’s mill; for the value of his method looked to the greater yield of choice flour.
The reissue-says: “It is this intermediate treatment (between the separation of the superfine flour and the completion of the mid-dlings flour by regrinding and rebolting) for the separation and removal of the pulveru-lent impurities which distinguishes my improvement in the art from all before known modes of manufacture.” In the original patent there is not only no such claim, but *683nothing is said about the removal of pulveru-lent or any other impurities, or any such intermediate treatment A brief use of air in an expanded portion of one reel at Lagonda, •operating as a separator, was soon abandoned in the course of the early experimenting, and, hence, in the original patent no use of •air in the separator was mentioned.
NOTE, [from original report.] Questions ■growing out of this patent, see American Mid-dlings Purifier Co. v. Atlantic Milling Co., .[Case No. 305;] Same v. Christian, [Id. 307.]The proof is that in the modem or present mode of purifying middlings, the purification occurs in connection with what answers to •Cochrane’s separator; and in that connection a current of air is now employed, while Cochrane did not call for any blast of air •at that stage of the process, and previous to regrinding. His plan or process was not to use blasts of air in connection with the separator, but to rely on the ordinary process •of screening, without the use of air blasts or currents. The reissue attempts to expand the original invention to cover, therefore, in connection with the separator, what he did not originally claim or suggest, in order that he might appropriate to himself what had been since discovered or used outside of his invention.
As the conclusion is reached that the reissued patent is void, it is unnecessary to consider whether the process claimed was anticipated in any of the various publications, ■or by any of the persons or processes as set up by defendants. The questions concerning “high milling,” the French and economical processes as used in Europe, the connection of the Oabanes and other patents with such processes, and also of Gove’s method and machine, would, if fully considered, involve •a very elaborate investigation of details, and require, for a clear presentation of their analysis, resort to numerous drawings and models.
If the reissue had been held valid, an embarrassing and delicate question would have arisen concerning the alleged infringement by the defendant. In the case of Cochrane v. Deener, [94 U. S. 780,] the United States •supreme court decided that the Welsh patent was an infringement of Cochrane’s. That court had before it not only the process patent of Cochrane, but also his patents for machines; and to what extent this court, under the circumstances, should venture to enter upon the subject anew — if an investigation as to that point were needed — might be doubtful. But, if an appeal is taken, that court will have before it in this suit the large amount of new evidence introduced, in the light of which it can determine for itself whether it will review its former opinion or not. Were it necessary for a decision on that point to be now made, and were it open for our consideration, we might possibly reach a different conclusion. Decree accordingly.