Statement of the case. chine, the other for the process. In the spring of 1860 these patents were extended, and afterwards, December 3, of that year, they were surrendered and reissued with what were alleged to be amended specifications; the bill being filed on these reissues of 1860, numbered respectively No. 1086 and No. 1087; the former for process, and the latter for machinery. The court below dismissed the bill, and the case came here by appeal. These reissues, with the amended specifications, were conceived by the appellant Burr, to have been justified in his case by the terms of the Patent Act of 1836 (§ 13), allowing such reissues in certain cases, and among them in the following one, to wit: "Whenever any patent shall be inoperative or invalid by reason of a defective or insufficient description or specification." The chief questions in this court were in effect,— 1. Whether a certain machine, patented to one Seth Boyden, infringed in terms the machine part of the patent originally granted to Wells? 2. If it did not, whether, under the right given by the Patent Act of 1836 (§ 13), to surrender and have a reissue in certain cases provided for by the act, the owner of the original patent could, by such surrender and reissue of a patent, enlarge its operation in a way which the present complainant sought to do, and which is stated farther on? 3. Whether Wells was the original inventor of the process part of his patent? In their more general aspect, however, the first two questions involved some of the fundamental principles in the law of the issue and reissue of patents; and they were argned elaborately and with great ability on both sides. The learned Justice GRIER, J., who delivered the opinion in one of the cases here reported (see postea), refers to the "large museum of exhibits in the shape of machines and models" which had "been presented to the court," and which, he states, were "absolutely necessary to give the court a proper understanding of the merits of the contro Statement of the case. versy." Most of them were introduced by the defendant, and they were arranged and explained with admirable clearness by one of his counsel, Mr. George Harding.* Drawings-of which but three can here be given-supply imperfectly originals thus advantageously presented. Without them, however, no idea at all can be had of the case; and the reporter trusts that while, from the special difficulty above referred to of understanding the case perfectly, without an inspection of actual machines, he will be pardoned for a statement of it which may be not intelligible to all; he will, on the other hand, be excused for incumbering a book of law reports with drawings, which, in the eyes of a casual observer, will give to it the aspect of a treatise on physical science, more than the aspect of one on the science of jurisprudence. Any complete understanding of the principles which the case embraces and settles requires some preliminary explanation of the particular art which happened to be the one in which the questions were presented to this court; the art, to wit, of the hatter. EXPLANATION OF THE art. Hat-bodies are manufactured out of fibres of fur or wool felted together. The fact that when the fibres of wool or fur are moistened and rubbed together, they would interweave spontaneously and form the fabric called felt, has been known from a remote antiquity. The process of felting is believed to have been anterior to the art of weaving. In Asia felted wool was used at a very early day for making tents, cushions, and carpets. It was known to the Greeks as early as the age of Homer, and is mentioned by him, and also by Xenophon and Herodotus. Its use was introduced into Rome from the Greeks, and it is mentioned by Pliny. Felt hat-makers appeared in France, in Nuremberg, and in Bavaria, early in the fourteenth century. It had been con * The whole business of making hats, from the disintegrating of the fur to the production of a hat-body, was actually carried on and exhibited in the court-room. Statement of the case. jectured by Monge, a French savant, in 1790, that felting was probably due to small scales on the fibres of fur or wocl, but, as nothing of the kind was found by the aid of the microscope, the idea was set aside by Dr. Young and other philosophers. Mr. Youatt, an intelligent English naturalist, in 1835, in investigating the subject of felting, carefully re-examined the fibres of wool, and the fur of rabbits and other animals, under a powerful achromatic microscope, and found that each fibre of fur or wool has its surface covered with serrations or sawlike projections, and that all these serrations pointed in a direction from the root towards the Fig. 1. Fig. 2. point of the hair. The appearance of a short piece of a fibre of wool under the microscope is shown in figure 1, and the wool or fur of the rabbit in figure 2.* The fur of the rabbit does not exceed in diameter the one-thousandth part of an inch; and in an inch of length of each fibre there are found to be 2880 of these serrations. In order that the fibres of fur or wool should felt, it is H necessary that the relative position which they occupy in nature should be changed, and the direction of the serrations on the fibres shall be reversed to each other, as shown in figure 3, instead of being pointed in the same direction as in nature. The thorough separation of the individual fibres of fur from each other is one of the first essentials in manufacturing fine felted fabrics; not only for the purpose just mentioned, but also to prevent the formation of lumps. The well-known instruments for separating or disintegrating Fig. 3. The great majority of hat-bodies are made of the fur of the Russiar hare, the English or the American rabbit, the coney (a small species of rab bit) the nutria and the beaver. Statement of the case. fibrous material are the carding engine, the picker, and the bowstring. The carding engine is the most complete and generally used instrument for separating all fibrous material, as wool, cotton, fur, and silk. It is shown on the body of the instru ment, drawn in figure 6 (page 538); that part of the instrument on the left of the dotted line, and marked F, 2, c, e, b, D, being left off. The carding machine is composed of one central main cylinder, covered with an almost infinite num ber of fine wire teeth. On the finer qualities of cards there are 79,000 teeth in every square foot of surface. This fine wire-pointed surface turns in contact with a succession of fine wire-teethed surfaces, and between these points the fibrous material is thoroughly disintegrated or scratched apart and separated. When operating on fur a fan (F)-in this plate a rotary fan-wheel-is attached to it, to throw the fur after it has been so separated. Another mechanism ordinarily used for disintegrating fibrous substances in the arts is the "picker" or "devil," D, which is shown in figure 10 (page 549), and consists of a series of very short, stiff, metallic teeth or studs, arranged at intervals on the periphery of a cylinder, and which is revolved with great rapidity. It acts by striking or whipping the fibrous material into or against the air with great velocity, and thus scatters it into distinct fibres. The bowstring is a vibrating cord, which also acts on the fur in a similar manner to the picker. being twanged it vibrates, and it whips By Fig. 4 Statement of the case. or strikes the fibres of the fur or wool a sharp and rapid blow against the air. Felt was merely used as the foundation or body for the hat, which body was first stiffened and then shaped into the figure of the ordinary stiff cylindrical hat; and finally, its exterior surface was made to have the appearance of a glossy fur. A finished hat was formerly made in the following manner: The "body" or foundation was first made of beaver, or rabbit, or coney fur; first, by the fibres being deposited in the form of two triangular pieces by means of the hatter's bow, as shown in figure 4, and then felted by rubbing by hand. In forming the body the skill of the workman directed the fur towards the brim or tip, as was required; it being generally necessary to make the brim thick. The bodies were then taken to the kettle, or battery, containing boiling water, where, by the workman's repeatedly immersing the body in hot water, and rubbing it on the shelf with his hands for about the space of an hour, the fibres of fur were forced to interlock or felt. The operation is seen in figure 5. Under this process of "sizing," as it is called, the |