profits made by him by reason of his unlawful acts and the damages which the plaintiff has sustained thereby, and that the actual damage assessed be increased to a sum equal to three times the amount of such assessment under the circumstances of the willful and unjust infringement by him.

The answer alleges that the plaintiff's patent is void, in that prior to Fuller's supposed invention, or more than two years prior to his application for his original patent, the alleged inventions or improvements referred to in the bill of complaint and in the reissued patent had been patented or described in certain specified United States letters patent, French letters patent, and German letters patent, and in other printed publications.

The learned District Judge thought the validity of the patent was open to question, but did not decide it, simply holding that there was lack of infringement. The bill was accordingly dismissed.

Edwin J. Prindle, of New York City (Warren H. Small, of New York City, of counsel), for appellant.

Walter D. Edmonds, of New York City (Philip C. Peck, of New York City, of counsel), for appellee.

Before WARD, ROGERS, and MANTON, Circuit Judges.

ROGERS, Circuit Judge (after stating the facts as above). The patent in suit is for certain new and useful improvements in papermaking machines. The invention relates especially to machines for handling tissue or other thin papers, and is particularly applicable to what is known as the Harper-Fourdrinier type of machine, although also applicable to other paper machines, as, for example, to those of the cylinder type. The object of the invention is to prevent the pulp from sticking to the upper metal press roll of the paper-making machine and to cause it to be carried unbroken to the "driers."

[1] A paper-making machine consists of means for forming a sheet of paper from properly prepared pulp, or paper stock, extracting the water from the stock, pressing it, drying and smoothing the paper, and preparing the finished product for market sizes and requirements. Machines used for this purpose are tremendous pieces of mechanism, averaging 100 feet in length and 25 feet in width, and being 10 to 12 feet high. They weigh from 100 to 200 tons, and run at a speed of from 200 to 450 feet a minute. The pressure roller 22 of the patent in suit, which appears in the drawing in a subsequent part of this opinion. and which looks so small itself, weighs approximately one ton.

The manufacture of paper appears to be an extremely difficult art. Those engaged in it describe it as such, and say that it required a great deal of skill, experience, and knowledge. The art of paper-making involves: (1) The shaping of the saturated pulp into a continuous sheet. (2) The drying of the sheet.

The ultimate stage of the shaping has long been accomplished by the aid of a coacting pair of rollers, known in the art as "press rolls," between whose compressive "bite" the pulpy sheet is pressed into its final thickness, and most of its water squeezed out; its cohesion and strength being thereby augmented. The sheet as it emerges from the press rolls is still so wet that it is fragile and industrially useless. The next step is to dry it, and this is done by bringing the sheet into progressive contact with one or more internally heated rotary cylinder drums, to which the sheet is transferred as directly as possible on its

(273 F.)

emergence from the "press rolls," and thus brought into progressive contact with the hot peripheries of the cylinders or drums until it is sufficiently dehydrated or dried.

Standard paper-making machines comprise three main elements: (1) A forming wire or screen, on which the wet pulp is deposited. (2) Press rolls, to squeeze water from the wet pulp and compress or mat the fibers to form a web. (3) A series of drums, called driers, to complete the paper.

The patent in suit adds to these three standard parts an attachment for conveying the moist web from the press rolls to the driers. Heavy papers have sufficient strength to pass from the press rolls to the driers without difficulty. But light-weight paper, such as very thin tissue paper, does not have sufficient strength for that purpose. Prior to the invention in suit the web of wet paper had to be carried over by hand from the press rolls to the driers. This was a difficult thing to do, and to do it required skill and training. To accomplish it one had to move his hands at the same speed the machinery was going. In the process the paper was constantly breaking. The problem which the inventor had to solve was so to equip a paper-making machine that the web of thin tissue paper could be taken from the couch roll through the press rolls and onto the first of a series of driers automatically and without breaking the paper. This it is claimed Fuller succeeded in doing,

Claims 1 and 2 of the patent are illustrative and read as follows: "1. In a paper-making machine, the combination of press rolls, a drier, a bottom felt, and a top felt, the bottom felt passing between the press rolls, the top felt passing from the upper press roll to and into contact with the drier, and another roll for pressing the top felt against the drier at or above the level of the axis of the drier.

"2. In a paper-making machine, the combination of a couch roll, press rolls, a drier, a bottom felt, and a top felt, the bottom felt passing around the couch roll and between the press rolls, the top felt passing from the upper press roll to and into contact with the drier, and another roll for pressing the top felt against the drier at or above the level of the axis of the drier."

The plaintiff offered in evidence a certified copy of the patent in suit, marked Exhibit 5, Figure 1 of which is here reproduced:

Figure 1 represents the Harper-Fourdrinier machine, with Fuller's attachment, which is the patent herein involved; and Fuller's testimony concerning it was as follows:

"Q. Did that machine have the felt 20 thereon when it first was set up on the floor and when you tried unsuccessfully to take a web of paper over it without breaking it? A. It did not.

"Q. Did it have the roller 22 thereon? A. It did not.

"Q. Did it have the hand lever 23 thereon? A. It did not.

Q. Did it have all the other parts shown in this drawing? A. It had all the parts, except the support for the top felt 20 and these parts that you just specified, roll 22 and rod 23.

"Q. Now, by reference to this same Figure 1 of the drawing and using the reference characters thereon, will you please explain just what you did to that machine so that it operated successfully without breaks? A. I took the gear off the drier 21, put a drive pulley on the back end of bottom press 19 to drive this drier 21, put a frame on top of frame 17 to carry felt 20, which I put around top press 18 and around roll 22, and put on a tension rod 23 for pressing this roll 22 against the overhang drier of a series of driers.

"Q. How did you connect the drive pulleys on drier 21 and press 19? A. With a belt.

"Q. Did you add the roller 22, or was that on the machine as it was delivered? A. I added it.

"Q. Was there any reason for having the roller 22 press against the drier 21? A. To make the paper leave the felt and go onto the drier roll.

"Q. What do you mean by the drier roll? A. The overhanging drier of a series of driers.

"Q. What is the reference character attached to the drier to which you refer? A. Reference character 21.

"Q. Is there any significance in the location of the roller 22 with reference to the axis of drier 21? A. I don't understand your question.

"Q. The roller 22 is shown above the axis of drier 21. Could roller 22 have been placed below the axis of drier 21 with equally satisfactory results? A. It could be placed anywhere on the drier above the center. I found it worked better right where I had it.

"Q. Was there any advantage in placing it above the center? A. It was more inclined to follow the drier than if it was down lower on the drier. Gravity helped along with the pressure.

"Q. Did the machine on which you placed your attachment in the summer of 1909 operate successfully thereafter? A. It did.

"Q. For how long? A. Still in operation."

Fuller further testified as follows:

"Q. Please state the advantages which your invention has which apply to a paper-making machine. A. The greatest advantage is that you can run a thin sheet of paper and not have it break. Another advantage is that this increases the speed of the machine; you can use a poorer grade of stock.

"Q. What do you mean by stating that it increases the speed of the machine? Please explain a little more fully. A. You can run the machine at a faster speed. I have known machines before this attachment was put on make paper at the rate of 200 feet a minute. I know machines now that are running 450 feet with this attachment, and it would not be possible to do it without this attachment on.

"Q. Why is this so? A. Because the paper would break on the press; there is nothing to automatically carry it on to the first drier. In the other styles of machines it had to be carried from this press to drier over by hand. This was a very difficult job and the paper would break in two. With this attachment it is delivered automatically from the press to the first drier of a series of driers.

"Q. What ordinarily limits the speed of a paper-making machine of the kind to which you have referred? A. The ability to keep the paper over the machine.

"Q. By keeping the paper over the machine you mean running the paper without breaks. Is that correct? A. Yes."

The explanation given of the exhibit illustrating the Harper-Fourdrinier standard type of machine follows:

(273 F.)

The wet pulp is contained in a head box 10 (near the center of the drawing at the bottom), from which it is spread on the straight top of an endless forming wire 11 (at the left of the drawing), from which it is taken off by an endless belt or felt called a lower felt 15 and conveyed to the press rolls 18, 19 (near the right of the drawing). A couch roll 16 keeps the felt in contact with the forming wire 11. All this is old and standard practice, as well as the series of driers 21, to which the pulp sheet passes from the press rolls 18, 19. It was the practice before the present invention to have the upper press roll 18 bare and convey the paper by hand (when starting the machine) from the press rolls 18, 19, to the first of the series of driers 21. This is still standard practice for heavy papers, which have sufficient body and tensile strength to permit their being scraped from the upper roll 18 by a doctor knife, and then pass the gap to the first of the series of driers without danger of breaking. With very light tissue paper, however, the wet pulp sheet is so tender that it does not scrape readily from upper press roll 18 and breaks continually between press roll 18 and the first of the series of driers 21. When the paper breaks at this point it is necessary to stop the machine and carry the paper on to the drier by hand or by a sheet of cardboard. This lowers the quality of the product, and also diminishes the output, as the machines must be run at a comparatively low speed, so that in case of a break the amount of paper wasted before the machine can be stopped will not be too great. Notwithstanding these disadvantages, this practice was common in the manufacture of tissue paper until the attachment of the patent in suit was placed on the market, although many attempts were made to overcome the difficulty. The practical attempts to overcome the difficulty consisted of various devices and modifications to upper press roll 18 to prevent the wet pulp sheet from sticking thereto.

The attachment of the patent in suit cured the difficulty by running an upper continuous band called an upper felt 20 between the press rolls and onto the first drier 21, against which the felt was pressed directly by a pressure roller 22. Pressure at this point by the roller is essential to make the paper leave the felt and stick to the first drier and the pressure of pressure roller 22 on the first drier 21 was made adjustable so that the pressure could be varied to suit varying conditions. The exact position of pressure roller 22 on first drier 21 is not essential, so long as the pressure roll 22 is above the center of first drier 21. Its position is changed according to the particular work in hand. Some mills run first drier 21 hot and other mills run it unheated. It is obvious that with an unheated first drier the arc of contact which felt 20 makes with first drier 21 may be greater than if the drier is hot, as the heat bakes the felt and destroys its life. In case the machine is stopped, moreover, a hot first drier' would injure the felt, which is prevented by having the first drier unheated.

Among the advantages of having pressure roller 22 above the center of first drier 21 is the aid afforded by gravity in causing the sheet of wet pulp to leave the felt and adhere to the drier and the benefit derived from having the pressure roller (which is more than 10 feet in length and weighs approximately a ton) supported throughout its length instead of by its ends only. When a roller of this size is supported only by its ends it tends to sag and tremble at high speeds and spring out of line, thus drawing the paper unevenly. Although the invention of the patent in suit added to a standard type of machine only the upper felt 20 and the pressure roller 22, some of the claims cover these parts in combination with the parts with which they coact including the lower felt 15 and the couch roll 16 around which the lower felt runs, as the entire machine is made automatic thereby. The machine is so completely automatic with the attachment that in case a break does occur it is not necessary to stop the machine, as the broken end, no matter where It occurs, is carried over by the felt onto the first of the series of driers.

The invention has been a commercial success. The principal tissue mills of the country use it, paying royalties to the plaintiff therefor. The largest mill machinery builders in the world are licensees under the patent in suit. A number of the oldest, most experienced, and most

successful paper manufacturers in the country testified that the plaintiff's device is standard practice in paper mills making light-weight tissue paper, and that they did not know of any other device which was satisfactory. Their testimony shows that the device enables the machines to be operated at an increased speed of from 20 to 50 per cent., and that it accomplishes automatically a particular part of the work which previously had to be done by hand. A paper manufacturer of 40 years' experience, the president of the Victoria Paper Mills Company, which operates its plant night and day 6 days in the week, testified that all the machines in his plant had been equipped with the plaintiff's device, which he began to use 4 years before, and that he did not know of any device which would work as satisfactorily as the device of the patent. He was asked whether it was standard practice, and answered: "Yes; I do not know of anything else." He was corroborated by other witnesses of almost as wide an experience. There is no testimony in the record which contradicts them. There can be no doubt as to the

utility of the device.

[2] The courts hold that it is not essential to patentability that an invention should be the best of its kind. Lamb Knit Goods Co. v. Lamb Glove, etc., Co., 120 Fed. 267, 56 C. C. A. 547; Crown Cork & Seal Co. v. Aluminum Stopper Co., 108 Fed. 845, 48 C. C. A. 72; Wheeler v. Clipper Mower, etc., Co., 10 Blatchf. 181, Fed. Cas. No. 17,493. But the record in this case makes it evident that prior to this device there was no way of running a thin sheet of paper through the machines without having it break at the press rolls, and it had to be carried over by hand. This device obviated both difficulties. The paper did not break, the device operated automatically, and the speed of the machines was increased from 20 to 50 per cent. Its evident utility, its absence of other competing devices, and its extensive use strongly attest its patentable merit. Lorillard v. McDowell, 15 Fed. Cas. 893, No. 8,510.

[3]. The court below held that the plaintiff failed on the issue of infringement for two reasons: (1) Because he thought that Fuller probably meant by "drier" only a hot drum. (2) Because, if Fuller meant to include a cold drum, his patent would have been invalid. We have no way of judging Fuller's intentions, except by what he said. In an application for a patent, and basing it upon a specification which the applicant declares to be "a full, clear, and exact description of the invention," we think that the inventor has clearly indicated his intention by the language he has used, and that no reason really exists for speculating as to what he meant by what he said.

[4, 5] A patent is subject to the same general rules of construction that apply to other contracts; for a patent is a contract made by the acceptance by the government of the proposition made by the inventor in his application. O. H. Jewell Filter Co. v. Jackson, 140 Fed. 340, 72 C. C. A. 304. Patents are to be liberally construed, so as to secure to an inventor the real invention which he intends to secure by his patent. There are cases in which an element described in the specification of a combination or device claimed has been read into the claim from the specification. This court has held that the specification may be