Sec. III.-ADMISSIBILITY OF WITNESSES AND TES

TIMONY.

It is held that persons who have used the machine for which the patent is taken out, are not thereby rendered incompetent as witnesses, on account of interest; even where the object of the defence was not merely to defeat the claim for damages, but also to have the patent declared void.75

A witness, being patentee in another patent, had sold to the defendant the right to use the machine, the use of which was complained of as an infringement; held that he was a competent witness notwithstanding, since any verdict that the plaintiff might recover, could not be given in evidence by the plaintiff in a suit against the witness.74

On a scire facias to repeal a patent for a machine, for the roving, preparing and spinning of wool, on the ground that it was not new; a witness testified that he had long before the patent, constructed a machine for the same purposes; and to show that it was similar to the defendant's machine, the counsel for the prosecution put into the hands of the witness a drawing of the machine constructed by him; the drawing, however, was not made by the witness. It

73 Evans v. Eaton, 7.Wheat. R. 356; Evans v. Hettich, 7 Wheat. R. 453.

74 Treadwell and Watson v. Bladen, 4 Wash. C. C. R. 704.

was objected that he ought not to look at it, but should describe the machine he had constructed. Bayley J. "I think the witness may look at the drawing, and you may ask him whether he has such a recollection of the machine he made, as to be able to say that that is a correct drawing of it."75

CHAPTER XXI.

Law and Fact.

THERE is nothing peculiar to patent causes as distinguishing them from others, as to the respective provinces of the court and jury.

It is a general rule, applicable in trials of actions for the infringement of patents, as well as in other trials, that the construction of a written instrument, is matter for the court, as far as the construction is to be determined by the instrument itself, or by a reference to statutes and principles of law merely, but the meaning of particular words and phrases, as governed by custom, is matter of fact for the jury. This rule applies to the patent and specification."

75 Rex v. Hadden, 2 Car. and P. 184.

1 The King v. Wheeler, 2 B. & A. 348.

Accordingly, where the inquiry is whether the invention be sufficiently described in the specification, where it can be decided only by an examination of the machine, this is a question for the jury. But if the question be, whether the specification is susceptible of any sensible construction, there being no dispute about the meaning of the words and phrases, it should seem to be a matter for the determination of the court, since the court must decide on a construction, and it seems to follow that they must decide whether the instrument admits of any sensible construction. Whether the invention be described with reasonable certainty was accordingly ruled by Mr. Justice Story to be for the court." Though Lord Eldon intimates that the question of the intelligibility of the specification is for the jury. And Mr. Justice Washington, in a case where he professed that he could make no sense of the specification and drawings, submitted them to the jury, to make what they could of them.5

Whether a specification be so clear and full, as to enable a person of ordinary skill in the art or science of which it is a branch, or with which it is most nearly connected, to make, compound and use the same, is a question of fact; since what is, or is not

6

2 Evans v. Eaton, 7 Wheat. 428.

31 Mason's R. 190.

* Hill v. Thompson, 3 Meriv. 630.

Gray and Osgood v. James, 1 Pet. C. C. R. 400.

• Per Story J. Lowell v. Lewis, 1 Mason, 190.

ordinary skill, is so. But this is a different question from that whether the language in connexion with the drawings and other helps to the meaning which it is allowable to resort to, such as dictionaries and the common usage, is sense or nonsense.

The question of infringement or no infringement is generally, if not invariably, for the jury. Whether the patentee is the inventor of any part, or of the whole machine, is matter of fact; and the jury must, accordingly, determine on the identity of the machine with, or its diversity from, one before known.9 So Mr. Justice Story ruled that "whether the principles of a machine are altogether new, or whether the machine be an improvement only, on those which have been in use before the invention, is a question for the jury to decide.10

In an action for an infringement of a patent for an improvement in the construction of pumps, Mr. Justice Story held that the question, whether the differences between the pumps constructed by the plaintiff, and those by the defendant, were mere change of form, without any material alteration in the structure, or whether they were substantially

7 Boulton v. Bull, 2 H. Bl. 4.

8 Whittemore v. Cutter, 1 Gallis. 478.

' Pennock and Sellers v. Dialogue, 4 Wash. C. C. R. 538.

10 Whittemore v. Cutter, 1 Gallison, 478.

different combinations of mechanical parts, to effect the same purposes, was a question of fact."

But in a case before Lord Wynford for an infringement of Barton's patent for an improvement in metallic pistons of steam-engines, the court took upon itself to decide that the pistons, which were alleged to be infringements, were not the same invention as that described in the plaintiff's specification.12 The doctrine of this case is directly inconsistent with that of those above cited.

Whether the invention be useful, has been held, in some cases, to be for the court, in others for the jury. It must depend upon the ground upon which the utility is impeached; if upon the ground that the specification itself, without going further, shows that the invention is against law or good morals, the court decides the question. Mr. Justice Livingston says that, "where it becomes a matter of inquiry whether the benefits of an invention are of sufficient consequence to be protected by the arm of the government, it may be proper to leave such question with the jury. But where the objection raised is, that the invention, on the plaintiff's own showing, is not only of no use, but an imposition on the public, it may be doubted whether a court transcends its

11 Lowell v. Lewis, 1 Mason, 191.

12 Barton v. Hale, Godson's Supplement, p. 65.