The bill recites the grant and issue, on December 16, 1890, of letters patent No. 442,855, for improvement in apparatus for reheating and finishing glassware, to A. J. Beatty & Sons, as assignees of M. R. Caldwell, and the assignment of the title thereto to George Beatty, one of the complainants; the grant and issue, on March 14, 1893, of letters patent No. 493,302, for improvement in apparatus for manufacturing glassware, to Herman Schulze-Berge, and the assignment of the title thereto to the National Glass Company, another of the complainants; alleges that the inventions of said patents are capable of conjoint use, and have been so used by the defendants, and prays in the usual form for an injunction and account.

The answer admits the grant and issue of the letters patent aforesaid, but denies infringement, and denies that it has used the said alleged inventions conjointly, or that they are capable of conjoint use. Replication was duly filed, and thereafter, and after proofs had been taken by complainants, an amendment to the bill was filed, adding paragraphs which recited the grant and issue, on September 17, 1889, of letters patent No. 411,131, for improvement in furnace for heating glassware, to Herman Schulze-Berge, and the grant and issue, on February 18, 1890, of letters patent No. 421,621, for improvement in the manufacture of glassware, to said Herman Schulze-Berge.

The answers of Bryce Bros. Company and of Andrew H. Bryce, president, to said amended bill, are to the same effect as the answers to the original bill.

Subsequently to the closing of the proofs, to wit, on June 13, 1901, notice in writing was given by complainants' counsel that he would not, at the hearing, insist upon any recovery from defendants upon the claims of letters patent No. 421,621, granted to Herman SchulzeBerge.

The case came on regularly for hearing, and an opinion was filed sustaining the charge of infringement as to patents Nos. 411,131 and 442,855, and finding that infringement of patent No. 493,302 had not been shown. Patent No. 421,621 was not considered or passed upon by the court. A decree was entered accordingly for an injunction and account. An appeal was allowed from so much and such parts of the decree as award an injunction and account in respect to the first claim of patent No. 411,131, and the fifth and sixth claims of patent No. 442,855.

The broad contention of appellants, underlying their assignments. of error, is that the state of the art at the date of the application for both of the patents, with which we are here concerned, was such that neither of them was entitled to the character of being primary or pioneer, and should not be dealt with as such, nor be entitled to a broad range of equivalents in considering the question of alleged infringement, but that the claims of each of the patents must be limited to the specific combination and precise improvement described; and that as the appellants did not make or use the specific form of device shown in the patents in suit, the plaintiffs below have no just cause of complaint.

Both patents relate to improvements in furnaces for reheating parts. of glassware up to the melting point. The earliest of the patents here

involved, No. 411,131, purports to cover such an improvement. The art involved is that of "fire finishing" blown or pressed glass articles, by subjecting them to a high temperature, in which their sharp edges are melted and smoothed down, and imperfections, such as mould marks in their original manufacture, removed. Previous to the devices embodied in the patents in suit, a pressed or blown glass article, the top edges of which needed to be melted and smoothed down, were inserted into what is called a "glory hole" in the side walls of a reheating glass furnace, where they were revolved until sufficiently smoothed and polished. This was generally done by a man or boy, who fastened the glass article on the top of a rod, by a small lump or ball of soft glass, the glass article being inserted in the glory hole. horizontally, and revolved by the turning of the rod in the hands of the one holding it. This hand method was somewhat crude and had certain obvious disadvantages, among which was the necessity of inserting the glass article (a tumbler, for instance) horizontally through the glory hole, which position in itself tended, in the softening of the glass, to deflect the structural axis of the article from a right line at its outer rim, unless great care was exercised by the one who handled and revolved the rod or warming in punty, as it was called. It is upon this view of the art alone that the learned judge of the court below based his opinion, in considering the advance made by the devices of the patent in suit. By this view, a change per saltum was assumed, from the hand method as just described to the mechanical method and device of the patents in suit.

In relation to such a conception of the state of the art, the first of the patents decreed to be infringed, called the Schulze-Berge patent, No. 411,131, describes an improved glass-finishing furnace, the floor of the combustion chamber of which extends out laterally, beyond the combustion flue of the furnace, so as to form projecting ledges which are accessible from below. In these ledges or projections of the floor, there are openings or glory holes, through which the glass articles to be reheated are raised vertically, by means of rods or similar instruments, and inserted into the combustion chamber, to be rotated thereon while supported in a vertical position. As set forth in the specifications of the patent, this furnace comprises an eye or combustion flue of refractory material. Above the flue is a combustion chamber, surmounted by an arched crown of the same material, which covers the floor of the chamber, and at the ends of the crown are openings which afford to the combustion chamber communication with flues which lead to a stack. The crown is said to be constructed after the manner of a reverberatory furnace, so as to deflect the burning gases as they emerge from the combustion flue down upon the floor. This device provided for the raising of the article, which was placed upon a holder, to which was attached a vertical rod, actuated by mechanical means for lifting it to, and into, the glory hole and withdrawing it, and also appliances for revolving it while subjecting it to the heat. There are undoubted advantages in this mechanical method over the hand method already described. Among the advantages, is that of raising the article vertically, requiring no gripping process, as the warming in punty did. The vertical

position had another advantage in presenting the article to the locus of heat, without the tendency to distortion that existed in the horizontal position, and as the article could be pushed up any required distance, and be easily withdrawn, only so much thereof as required fire polishing need be exposed to the heat. The first claim of this patent, decreed by the court below to have been infringed by the appellants, is as follows:

"1. A furnace for heating glassware, consisting in a combustion chamber provided with a floor over which the gases of combustion pass and which is provided with a glory hole or glory holes accessible from below for the introduction and withdrawal of a glass article, substantially as and for the purposes described."

The essential feature of this claim is a furnace, so constructed that it may have a floor, in which there may be a glory hole, or glory holes, accessible from below, for the introduction and withdrawal of glass articles. The apparatus set forth in the descriptive matter and claim, can be best understood by a reference to an illustration taken from Fig. 1 of the patent, in which unimportant reference symbols are omitted for the purpose of clearness. A reference thereto shows an apparatus consisting of a reheating furnace, having a combustion flue, a, gas burner, b, combustion chamber, c1, and glory holes, e, in combination with mechanism for presenting glassware from below to, and withdrawing it from, the glory holes, and for reheating it while exposed to the heat of the furnace.

The obvious purpose of the patentee was to design a furnace that would admit of the vertical presentation of the glass article to be reheated. As this could not be so readily accomplished at a glory hole in the side of the furnace, the construction must be such as to permit a glory hole through its floor. The essential structural peculiarity, therefore, is a furnace with a laterally projecting floor, c2, of

the combustion chamber, in which floor the glory holes are placed, so that a glass article may be vertically raised or lowered, in presenting it to them and withdrawing it therefrom. To make the floor of the combustion chamber in a glass-heating furnace accessible from below, was the problem to be solved, and such a floor, in combination with the mechanism for vertically raising the ware to be heated to, and withdrawing it from, the glory holes, constitutes the apparatus described in the patent and set forth in the claim quoted.

The specific reheating furnace described and set forth in claim 1 (which is the claim declared to be infringed by the court below) is the patented device with which we are here concerned. It embodies, as was stated by the court below, the "substance of the patent." The improvement claimed is appurtenant to a glass-heating furnace. Something that may properly be called "a furnace," is predicated by the description of the improvement. The prominent indispensable concept of such a structure, is some sort of inclosed combustion chamber, with top, sides and bottom, or floor. Indeed, the improvement described could not be applicable to a structure without a floor, as it consists in a floor made laterally projecting beyond the combustion flue, so as to be accessible from below. So, too, a combustion chamber necessarily implies an inclosed space, within which the gases of combustion may be confined. The terms "furnace," "combustion chamber," and "laterally projecting floor," in which glory holes accessible from below are situated, necessarily imply the definite structure presented to an ordinarily intelligent mind by such a description. These terms have a well-understood meaning in the vocabulary of the industrial arts. It is hardly necessary to refer to the definitions of the word "furnace," taken from standard authorities, as quoted by appellants. To the well-understood general structure of a glass furnace, the alleged improvement of the patent related, and consisted in the lateral projection of the floor of such a structure.

The other patent held to be infringed by the court below, conjointly with the one just described, is the so-called Caldwell patent, being No. 442,855. The patentee says in his specifications:

"My invention is directed to improvements in glory-hole furnaces, particularly designed for reheating glassware, for melting the edges and fire polishing the surface of such articles as tumblers, goblets, and other ware pressed or blown."

Claims 5 and 6 of the patent are those which are claimed to have been infringed. They are as follows:

"(5) In a glass reheating or melting furnace, a fire chamber having vertical wall openings and coincident bottom openings extending through the fire chamber and connecting two of said wall openings, in combination with a table arranged beneath the bottom of the fire chamber, having vertical ware carrying supports arranged in the line of said openings, and means for rotating said table for carrying the ware into the fire chamber through one wall opening and out at the other.

"(6) In a furnace for reheating and finishing glassware, the combination, with the furnace having vertical wall openings, and segmental bottom slotformed openings extending through the fire chamber and connecting two of said wall openings, of a table arranged beneath the said bottom openings and having several revoluble vertical ware carrying supports arranged to travel through said bottom slots, and means for rotating said table."

It will be seen that there is described and shown a glass furnace and combustion chamber, having the essential characteristic of that patented in No. 411,131, to wit, the laterally projecting floor, with the glory holes therein, and thus accessible from below. So far, the requirements of the two patents are identical. Both require a glassheating furnace, and both require that that furnace should be so constructed as to have a laterally projecting floor that would admit of a glory hole therein and be accessible from below. Instead, however, of a simple glory hole, into which glassware could be introduced or withdrawn vertically, we have a segmental slot through the floor of the furnace, connecting the wall openings therein, in combination with the table revolving on a center outside the furnace, and a little below the floor thereof. This table is so centered, that an arc of its circumference always coincides with the slot in the floor of the furnace, so that glass articles can be placed upon carriers situated on the circumference, in such manner as to reach up through the slot into the combustion chamber. Thus arranged, by the revolution of the table they can be carried successively and continuously through the heat of said chamber, an independent mechanism rotating the glass articles as they are carried through.

The validity of these patents is not directly attacked, but the contention is made by the defendant, that the inventions are not of a pioneer or primary character, and that therefore they must be confined