Upon this subject, Mr. Justice Washington, speaking of the continued use of such previously erected machine, after the issuing of the patent, remarks, that it was objected to the construction, that a party had no right to such continued use; "that it would render the law ex post facto in its operation, in respect to one who has erected his improvement prior to the granting of the patent to the plaintiff."

"It must be admitted that cases of great hardship may occur, if, after a man shall have gone to the expense of erecting a machine, for which the inventor has not then, and never may obtain a patent, he shall be prevented from using it by the grant of a subsequent patent, and its relation back to the patentee's prior invention. But the law, in this case, cannot be termed ex post facto, or even retrospective in its operation, because the general law declares, before hand, that the right of the patent belongs to him who is the first inventor, even before the patent is granted; and, therefore, any person, who, knowing that another is the first inventor, yet, doubting whether the other will ever apply for a patent, proceeds to construct a machine, of which it may afterwards appear he is not the first inventor, acts at his peril, and with a full knowledge of the law, that by relation back to the first invention, a subsequent patent may cut him out of the use of the machine thus erected."

"Not only may individuals be injured by a liberal construction of the words in the law, but the public

may suffer, if an obstinate or negligent inventor should decline obtaining a patent, and at the same time keep others at arms' length, so as to prevent them from profiting by the invention for a length of time, during which the fourteen years are not running on. But all these hardships must rest with Congress to correct. It is beyond our power to apply a remedy."

9910

So where a patent, first taken out, is void, on account of a formal defect in the specification, and on this account is surrendered and a new one taken out, but previously to the granting of the new patent, a machine is erected by another person, the party so erecting the machine, cannot continue to use it after the second patent is taken out, and his so continuing to use it will be an infringement." That is, he stands upon precisely the same footing as a person who erects and uses a machine before the first patent is taken out, when such first patent is valid.

Nor is any notice necessary, in such case, from the patentee to the party who has erected and begun to use the machine before the granting of the new patent. Where a patent for an improvement in a machine for making paper first taken out, was surrendered, and a new one taken out, and before the

10 Evans v. Weiss, 3 Hall's Law Journal, 180. Wash. C. C. R. 12; Fessenden's Patents, 52.

11 Ames v. Howard, 1 Sumner's R. 482,

second patent was issued, another person had erected the machine, and continued to use it after the second patent was issued; in an action for an infringement of the patent-right, the defendants objected that they were not liable until after notice from the patentee. Mr. Justice Story, however, ruled otherwise, and, on a motion for a new trial, said, "I am by no means prepared to say that any notice is, in cases of this sort, ever necessary to any party who is actually using a machine in violation of a patent right." But supposing notice to be necessary, he considered the knowledge by the defendants that the first patent had been taken out, to be, in effect, such notice. He said, "whoever erects and uses a patented machine, does it at his peril; he takes upon himself all the chances of its being originally valid, or of its being afterwards made so, by a surrender of it, and granting of a new patent, which may cure any defects, and is grantable according to the principles of law."'12

The judges considered that the above construction, as to the use of a machine, erected after the expiration of the old, and before grant of the new patent, was forced upon them by the law.13 But it does not appear why a doctrine evidently so inequitable, is imposed upon the court, since, on the ex

12 Ames v. Howard, 1 Sumner's R. 482.

13 Evans v. Weiss, Fessenden on Patents, 52; Wash. C. C. 12; 3 Hall's L. J. 180; Evans v. Eaton, 1 Pet. S. C. R. 337.

piration of a patent, the right is merged in the community, and every man has a license from the public to make, use and vend the article. His right in respect to such article is not distinguishable from that which he has in respect to any other which has been in use immemorially without patent. The reason is not shown why the public should not be entitled, under these circumstances, to use the machines that had been made before the renewal of the patent, at least. The more grave question is, whether the patent could, upon any sound principle of legislation, be renewed under these circumstances. Under the act of 1836, patents cannot be prolonged under the provision of the eighteenth section, unless the grant of prolongation is made before the expiration of the first term.

Sec. IV.-SELLING.

What is a sale of the patented article so as to be an infringement of the patent, needs not to be dwelt upon at great length. Though questions may be made as to what amounts to a sale, and as to the party who is to be considered the vendor, it would be a digression to go into a minute investigation of the subject in this place. Undoubtedly, the principal, who authorizes his agent to sell for his benefit, is an infringer of the patent. And so, also, is the

agent, for the orders of the principal are no excuse to him for the violation of another's right.

It has already been noticed, that a sale by operation or authority of law, as in case of bankruptcy, insolvency, and sale on execution, is not an infringement of the patentee's right."

Sec. V.-IDENTITY OF THING MADE, USED OR SOLD, WITH THAT PATENTED. DIFFERENCE IN FORM AND PROPORTIONS MERELY. INFRINGEMENT OF A COMBINATION OF A PART.

The making, using or selling of a thing, is, of course, not a violation of a patent, unless it be the thing, or one of the things patented. If it vary from the patented article, merely in form or proportions, but be substantially and essentially the same, it will be a violation of the patentee's right. This doctrine was directly involved in the provision of the act of 1793, by which a variation merely in form or proportions, was declared not to be a new invention, and so not patentable; that is, conversely, it is, within the meaning of the law, the same thing, and so is an infringement.

"What constitues form, and what principle," Mr. Justice Washington remarks, "is often a nice

14 Supra. ch. xvi.