Statement of the Case. destroying the length and felting quality of the fibre, whereas when the pulp is thin the pieces are ground individually, as it were, between the knives, and the integrity of the fibre in large measure destroyed; secondly, in the greater quantity of pulp which can be prepared in a medium of given size, owing to the larger proportion of fibrous material in the charge; and, thirdly, in avoiding the liability of the fibrous material depositing out of the liquid and lodging in the channels. "The operation of the engine is as follows: The beater-roll and bed-plate knives being adjusted properly, the vat is filled with the rags or fibrous material to be pulped and the proper quantity of water. The beater-roll being revolved at the proper speed-say, for a roll four feet in diameter, at the speed of one hundred and twenty revolutions per minute the rags and liquid are drawn between the knives, are carried up by the beater-roll, and thrown over the edge of the place P. They flow around the partition N with considerable velocity and return again and again to be acted upon by the knives. The roll is revolved until the pulp is properly reduced. "Modifications may be made in details of construction without departing from the spirit of the invention, and parts thereof can be separately used if desired." The claims alleged to have been infringed were as follows: "1. The improvement in beating rags to pulp in a rag engine having a beater-roll and bed-plate knives, consisting in circulating the fibrous material and liquid in vertical planes, drawing the same between the knives at the bottom of the vat, carrying it around and over the roll and delivering it into the upper section of the vat, substantially as described. "2. A rag engine for paper-making, comprising the vat, the beater-roll mounted on a horizontal shaft in one end of the vat, and the horizontal partition dividing the body of the vat into an upper and a lower section or passage, the fibrous material and liquid being carried from the lower section between the knives and delivered over the top of the beater-roll into the upper section or passage, substantially as described." The device employed by the defendant was manufactured Statement of the Case. under letters-patent No. 347,043, issued August 10, 1886, to John H. Horne, the defendant. With relation to the peculiar feature of his invention he stated in his specification as follows: "One great difficulty hitherto in the construction of these engines, whatever may be the path of travel given to the material contained in them, consists in the fact that the various fibres or bunches of fibre, after being placed within the engine, maintain concentric paths of movement with respect to each other. Thus a piece of stock located near the sides of the tub, or one placed near the mid-feather, will continue to travel in concentric paths until the engine is emptied, except in case manual labor is applied with a paddle to disturb their courses and compel them to deviate therefrom; hence it is obvious that the fibre travelling the more rapidly will be reduced more quickly, and the 'stuff' is of uneven quality. "The essential object of my invention is to effect a change in the course of the material in the engine automatically and obliquely to the longitudinal axis of the engine during each complete passage thereof around the tub, and thereby thoroughly mix the stock. Thus the particles which are nearest the mid-feather in one passage about the tub, and which therefore travelled the fastest, are directed and changed obliquely across the engine prior to their p about the roll, and hence they will emerge and are located near the side. Such stock will consequently travel the slowest during the next passage around the tub, since it remains contiguous to the retaining-walls of the latter. This mixing and stirring of the material within tub is effected primarily by the shape of the tub in cross the section, the width of which is equal to the active face of the roll, Thus to effect the desired change in the path of movement of the stock the proportions of the tub are altered, and in crosssection the two passages formed in the tub by the mid-feather are twice as deep as they are wide, or thereabout. Again, the stock is permitted to fill the entire width of the engine just prior to its entrance beneath the roll, and also immediately after leaving the same; hence the mid-feather terminates a or thereabouts, the latter located in one end thereof. VOL. CXLV-20 Opinion of the Court. short distance before reaching the roll, and the stock, as it approaches the latter, as before premised, is permitted to spread out and fill the entire width of the engine. After the passage of the stock between the roll and the bedplate, the particles composing it are directed upon and over the back-fall, which here extends entirely across the engine and in front of the roll, but contracts as it extends away from the latter, until it unites with the mid-feather, whence it is continued downward between the latter and the side of the engine to the bottom of the tub. This contraction of one-half its width again restores the mass of stock to a general vertical position, and the latter is so maintained until just prior to its return passage beneath the roll. Thus it will be evident that the fibres composing the material in process of being pulped cannot travel in continuous concentric paths of movement, but are changed and forced obliquely of the engine, whereby a thorough mixing of the stock is automatically effected by the spiral motion imparted to it both before and after leaving the roll." The case was heard in the Circuit Court upon pleadings and proofs, and a final decree entered dismissing the bill upon the ground that the defendant had not infringed the plaintiff's patent. 35 Fed. Rep. 830. From this decree the plaintiff appealed to this court. Mr. Philip Mauro and Mr. Anthony Pollok for appellant. Mr. Frederick P. Fish (with whom was Mr. W. K. Richardson on the brief) for appellee. MR. JUSTICE BROWN delivered the opinion of the court. The engine in ordinary use by paper makers for the reduc tion of rags to pulp prior to the invention in question consisted of a tub about fourteen feet in length with straight sides and semicircular ends. Through the centre of this ran a vertical partition called the mid-feather, extending lengthwise of the tub, and with sufficient room between the ends of Opinion of the Court. the partition and the ends of the tub to allow the pulp to pass around from one side of the tub to the other. Midway of the tub and between the mid-feather and one side was a wheel or beater-roll, armed with knives, placed longitudinally upon the periphery of the wheel. Beneath the roll were corresponding knives in the bed-plate, and by the revolution of the wheel the rags were drawn between these knives and reduced to pulp. At one side of the roll the bottom of the tub was curved upwards forming a ridge or dam, termed a back-fall, about four inches high extending across the channel parallel with the roll. The beater-roll revolved away from the top of the backfall, and the material being lifted by the rotation of the roll to the top of the back-fall, slid down the incline by gravity, which was the only force acting to cause a flow of nearly thirty feet, from the back of the beater-roll around to the front of it again. The speed of the pulp was thus necessarily very slow. 1. The novelty and patentability of the Hoyt patent were not denied, though two prior patents were referred to for the purpose of limiting its clains. The Umpherston engine was patented in England in April, 1884, a few months before the Hoyt patent was issued in this country. This machine differs from the old tub only in the fact that the mid-feather runs horizontally instead of vertically, and the return passage or channel for the pulp is underneath instead of alongside of the channel containing the beater-roll. Apparently the only advantage which it possesses over the old one is in of floor space. economy The Cooke engine, patented in England in 1880, is a machine of the type known as disk-grinders, and is not a beating engine of the type of the machines involved in this suit. It has no beater-roll, the grinding being done by two disks at the end of the tub between which the pulp is drawn in at the centre of the disks, and works its way outward to the periphery between the grinding surfaces. It seems to us to have little bearing upon the present case except in the fact that the grinding mechanism is located at the end of the tub instead of in the centre. The Hoyt engine differs from the old tub in ordinary use Opinion of the Court. in two or three important particulars. First, the beater-roll is located at the end of the tub, instead of in the centre, having in this particular a certain resemblance to the Cooke machine; second, the mid-feather runs horizontally instead of vertically, a feature in which it resembles the Umpherston engine; and, third, the beater-roll extends across the whole width of the tub, and its revolutions are toward instead of away from the top of the back-fall or dam. The result of this is such a greatly increased speed in the flow of the pulp that it is said to be brought in contact with the knives twelve times as often as was possible in the old tub or engine. The circulation of the material around the roll in vertical planes is the salient feature of the Hoyt invention, and its utility is shown in its general adoption by paper makers. 2. The main question in the case is that of infringement. In the defendant's engine the beater-roll is also located at the end of the tub and extends across its entire width; the top of the back-fall or dam also extends across the entire width in front of the beater-roll, but narrows at one side as it descends to the bottom of the tub to one-half of its width. The midfeather is made vertical instead of horizontal, so that the pulp after it leaves the dam circulates in a horizontal instead of a vertical plane; but as it returns to the beater-roll it passes back under the dam, spreading out to the entire width of the tub, and is taken up by the beater-roll precisely as in the Hoyt patent. It is insisted by the defendant in this connection that there is no infringement of the first claim of the Hoyt patent, since the pulp is not circulated "in vertical planes," nor is it delivered by the beater-roll "into the upper section of the vat," as specified in that claim. Literally it is not. A technical reading of the specification undoubtedly required that the mid-feather should run horizontally instead of vertically; but the object of this was that the pulp should be received and delivered by the beater-roll along its entire length, viz. across the entire width of the tub, and this is accomplished in the same way in both devices. In both engines the beater-roll revolves toward the top of the dam or back-fall, and a similar acceleration of speed is obtained. How |