With the court below we assume the validity of the claim in suit. As to the history of the art and the nature of Conner’s patented improvement, nothing need be added to the dis-' cusston of these matters by Rose, District Judge, in One Piece, etc., Co. v. Bisight Co., 246 Fed. 450, affirmed (C. C. A.) 259 Fed. 275. Upon the same authority we assume the invalidity of the first and third claims of Alexander’s patent, 954,772; therefore it was open to this defendant or any one else to -manufacture bifocal lenses of the style displayed by Alexander in bis invalidated claims.
The sole question in this case is whether the defendant by making some or all of the alleged infringements offered in evidence has violated Conner’s admitted right. It is a necessary preliminary to this inouiry to state exactly wliat we conceive to be the resulting form of a lens covered by the Conner claim in suit.
The language of the patent is that “the lens at the curved line of joinder of the upper and lower fields [has] a uniform thickness through both fields.” It is obvious that the word “line” is not used in the mathematical sense of exhibiting length without other dimensions. What Conner invented was a form of juncture between reading and distance lenses, which produced equal thicknesses of glass on each side of the exact junction line, but at small (indeed, almost miscroscopic) distances from said line. Thus, a vertical section of Conner’s construction would look like a similar section of a hill with sides of exactly equal curvature near the apex. Conner declares, and the testimony bears out, that this construction produces a “division practically free from prismatic effects.”
Conner’s patented result maybe obtained by means other than those disclosed in his method patent, 925,802; but, no matter what means or method be employed in the making of this patented article, fine work is required, skilled labor is necessary, and even then the percentage of failures rejected by rigid inspection is quite large.
The Alexander lens, which any one can make so far as patent rights are concerned, necessarily exhibits, even when completed according to Alexander’s disclosure, a shoulder or substantially vertical line delimiting and separating the reading and distance portions of the lens. A vertical section of that lens does not look like a hill, but like a pair of steps — the level of one step being the lens for distance, and the level of the other the lens for reading — and the separation between them is perpendicular.
We consider it proven beyond all doubt, and especially by the witness Zircher, called for the plaintiff, that defendant makes all its lenses in the Alexander manner, and not in that of Conner. It is, however, also proven that, when defendant has by machines produced what may be called an Alexander lens, it is subjected to a polishing process which *384wholly or partially removes the Alexander shoulder. Result is what defendant calls a “zone of aberration.” It is obvious that defendant’s resulting commercial product is a ruder, cheaper, and less accurately formed set of bifocal lenses than plaintiff’s carefully worked product.
But the only inquiry in this suit is whether the polishing of an Alexander lens in the manner amply testified to does or can produce the Conner lens. The differences between the comparatively cheap product of defendant and the carefully finished one of plaintiff are matters of millimeters; the difference cannot be determined by visual inspection, and we think that the court below fell into error in deciding this case, not upon the oral evidence, but by considering the appearance to a layman in such matters of plaintiff’s and defendant’s commercial products.
To us there are some of the alleged infringements that do not in the least resemble Conner’s disclosure, and there are others which we cannot distinguish from some of the plaintiff’s glasses. But causes cannot be decided in that manner; the evidence is that defendant starts his polishing process with an Alexander lens, and there is no evidence to show how, as matter of mechanics or mathematics, the polishing of what in vertical section looks like a pair of steps can be made into something which on vertical section resembles a hill, with equally curving sides.
We do not assert that the thing is impossible; but there is no evidence to show its possibility, and in our opinion all the probabilities justifiably based on the evidence indicate that this defendant has done no more than produce a cheap machine-made lens, possessing, and acknowledging the possession of that very “zone of aberration” which is sure to produce the “prismatic effects” that have been avoided by Conner’s scientifically accurate patented product..
Holding, therefore, that the evidence of infringement is quite insufficient, it is ordered that the decree bólow be reversed, with costs, and the matter remanded, with directions to dismiss the bill.