separate inventions and machines, the joint patent was for that reason void; but that the parties might procure its repeal and obtain separate patents for each machine."

In regard to the case put by Mr. Justice Story, of joining the invention of an improvement of one machine in the same patent with an invention of a combination of the machine, so improved with others, I cannot but think they may be joined, where the improvement in the separate machine, and the combination, have the same object; for, suppose the combination to be of two machines, one of which is improved ; the improvement is one addition, or modification, and the combining it with the other, is a second modification or addition. The case cannot easily be distinguished from divers improvements of the same machine, and that such divers improvements may be joined in one patent, there seems to be no ground to doubt.

A case decided in the English Court of King's Bench, presents a combination of things in the same patent, of very considerable diversity, though all the different things were used in connexion, viz. an improvement in ships' anchors, cables, and windlasses."

7 Stearns v. Barrett, 1 Pick. 448.

See Hill v. Thompson, 2 J. B. Moore, 424.

The objection was not made to this patent that it embraced distinct subjects of patents, so that on this point the case has only the feeble authority arising from the fact that the counsel did not raise the objection, and that the court did not, of its own motion, notice it.

Sec. IV.-PATENT FOR A PART OF A MACHINE.

We next consider whether a patent may be taken out for a part of a machine. A patent for an improvement is usually for a part of an entire thing, and often at least, if not most frequently, for something that cannot be used separately to any practical purpose. It is not necessary, then, that the subject of the patent or exclusive right should be capable of an independent separate use. But suppose the case of two persons, independently of each other, inventing the parts of a new machine, are they entitled to separate patents? Mr. Justice Story says, "if two persons invent several parts of a machine capable of a distinct use, then those parts might be considered as separate inventions, for which such inventor might perhaps be entitled to a separate patent."

9 Stearns v. Barrett, 1 Mason, 153

This qualification that the inventions should be capable of a separate use, seems to present a pretty clear case of a right to separate patents. But if the parts belong essentially together, and are useless when separate, this is a plain case of joint invention; though the inventors may have had no communication with each other; and so a case in which separate patents cannot be taken out. Neither inventor could reduce his invention to use independently of the other, and as we have seen, the inventor must, in order to entitle himself to a patent, reduce his invention to

use.

CHAPTER X.

Title of the Patent. Form. Difference in Form between English and American Patents. Construction of Patents.

WE come now to the inquiry, what steps and forms are necessary in order to secure the exclusive privilege granted by the patent acts. The principal subjects to be considered in this connexion, are the specification, the drawings, models, and specimens, the

oath of the inventor, the petition, the payment of the tax or fee, the reference to arbitration in case of interfering claims, the letter patent. It is proposed to notice here the different modes of granting patents in England and the United States, and as consequent upon this difference, a diversity in the rules of construction of patents. Unless this diversity is first noticed and kept in view, there will be some confusion and obscurity between the English and American cases on the subject of the specification.

The form of American patents was prescribed by the act of Congress of 1793, s. 1, which provided, among other things, that on a petition for the purpose, the secretary might cause letters patent to be granted, "reciting the allegations and suggestions of the said petition." Mr. Justice Washington ruled that a compliance with this requisition was material. In an action for an infringement of Evans's patent for the Hopperboy, it was objected that the patent did not recite the allegations and suggestions of the petition. Washington J. "If the allegations and suggestions of the petition are substantially recited, it will be sufficient. But in this case they are not." He said the patent gave no description of the hopperboy and its use, and the manner in which it worked. The petition gave a minute and full description of it, which

The

ought to have been substantially recited.' English law contains no similar express provision, but the practice is to recite the allegations of the petition, and the provision of the American statute in this respect, was, no doubt, borrowed from the English practice. The act of congress of July 4th, 1826, c. 357, s. 5, prescribes the form of the patent, omitting the provision that it shall recite the allegations and suggestions of the petition, and providing instead that it shall contain "a short description or title of the invention, correctly indicating its nature and design, referring to the specification for the particulars thereof," so that the above decision is not applicable to patents granted under this act.

In England the patent is granted before the specification is made, a certain time being allowed by the patent for enrolling the specification, varying from two to six months or longer, according to the circumstances, it being left to the discretion of the executive officers to fix the time. Though in one case in England Mr. Justice Grose is reported to have said, that the specification was fairly to be considered a part of the patent itself, the cases are entirely otherwise, and

1 Evans v. Chambers, 2 Wash. C. C. R. 125. 28 T. R. 105.