The patent is granted on condition that a specification be enrolled.

I give no opinion on the questions which arise. from the admission of certain witnesses, who were supposed to be disqualified, on the score of being interested; for if the patent for the Hopperboy be void, for a defect in its specification, and that question is not to be referred to the jury, and such I understand to be the opinion of four of the judges, it is very unimportant, whether any error was committed in this respect by the Court before which the cause was tried; as a verdict must ever be rendered against the representatives of the patentee, on this ground, whatever may be the state of the evidence.

Mr. Justice JOHNSON, and Mr. Justice DUVALL, also dissented.

Judgment affirmed with costs.

(COMMON LAW,)

EVANS V. HETTICH.

It is no objection to the competency of a witness in a patent cause that he is sued in another action for an infringement of the same patent.

The 6th section of the patent act of 1793, c. 156 which requires a notice of the special matter to be given in evidence by the defendant under the general issue, does not include all the matters of defence which the defendant may be legally entitled to make. And where the witness was asked, whether the machine used by the defendant was like the model exhibited in Court of the plaintiff's patented machine, held, that no notice was necessary to authorize the inquiry. Where a deposition has once been read in evidence without opposition, it cannot be afterwards objected to as being irregularly taken. It is no objection to the competency or credibility of a witness, that he is subject to fits of derangement, if he is sane at the time of giving his testimony.

ERROR to the Circuit Court of Pennsylvania.

This was an action for the infringement of the same patent as in the preceding case of Evans v. Eaton, and was argued by the same counsel. The points involved will be found to be fully discussed in the argument of that case, to which the learned reader is referred. The following is the charge delivered to the jury in the Court below, which it is thought necessary here to insert.

After stating the evidence on both sides, Mr. Justice WASHINGTON proceeded as follows:

The facts intended to be proved by the evidence given in this cause, may be arranged under the following heads.

1822.

Evans

V.

Hettich

1822.

Evans

Hettich.

(1.) Such as respect the value of the plaintiff's Hop perboy. (2.) The time of its discovery. (3.) The kind of machine used by the defendant. (4.) The time of its discovery and use.

1st. As to the first, the Court has no observations to make, except that if you should find a verdict for the plaintiff, you will give the actual damages which the plaintiff has sustained, by reason of the defendant's use of his invention, which the Court will treble.

2d. The evidence applicable to this head, if believed by the jury, proves, that in 1783, Oliver Evans commenced his investigation of the subject of an improvement in the manufactory of flour; and in the summer of the same year, he declared that he had accomplished it. In 1784, he made a model of his Hopperboy, which had no cords, weight, or pulley; and consequently the lower arm was, for the sake of the experiment, turned by the hand. In 1785 it was in operation in a mill, in as perfect a state as it now is.

3d. If the witness who was called to prove the kind of machine used by the defendant is believed by the jury, it consists of an upright square shaft, with a cog that turns it, and which is moved by the water power of the mill. This shaft is inserted into a square mortice, in an arm or board somewhat resembling an S, with strips of wood fixed on its under side, and so arranged as to turn the meal below it, cool, dry, and conduct it to the bolting chest. This arm slips, with ease, up and down the shaft and must be raised by hand, and kept suspended un

til the meal is put under it. It has no upper arm, pulley, weight, or leading lines; and the strips below the arm are like the rake, as it is called, in the plaintiff's Hopperboy. This machine has acquired the name of the S. or the Stouffer Hopperboy.

4th. The witnesses examined to prove the originality, and use of the defendant's Hopperboy, if believed by the jury, date it as early as about the year 1765; and its erection and actual use in mills, in 1775 and 1778; and progressively to later periods. Objections have been made, on both sides, to the credit of some of the witnesses who have been examined, not on the ground of want of veracity, or of character, but of interest, short of that which can affect their competency. These objections have been pressed so far beyond their just limits, as to require from the Court an explanation of their real value. Where the evidence of witnesses opposed by other witnesses is relied upon, by either side, to prove a particular fact, the jury must necessarily weigh their credit, in order to satisfy their own minds on which side the truth is most likely to be; and in making this inquiry, every circumstance which can affect the veracity of the witnesses, whether it concern their moral character, or whether it arise from some interest which they may have in the question, or from feelings favourable to one or the other of the parties, should be taken into the calculation. But if the fact in controversy may exist, without a violation of probability, and the proof is by witnesses exclusively on th side, there is nothing to put into the opposite scale, against which to weigh the credit of those witnesses:

1822.

Evans

V.

Hettich.

1822.

Evans

V.

Hettich.

and if the objection to their credit be worth any thing, it must be to the full extent of rejecting their testimony altogether, or else it is worth nothing. The jury cannot compromise the matter, or halt between two opinions ;-they must decide that the fact is so, or is not so; and if the latter be cause of objection to the credit of the witnesses, it would amount to the confounding of the questions of competency, and credibility; for the effect would be the same, whether the Court refused to permit the witnesses to testify on the ground of incompetency, or the jury should reject their testimony, when given, on that of want of credibility. I have thought it proper to submit these general observations to the consideration of the jury.

We come now to the question of law, which arises out of these facts, which is,

What are the things in which the plaintiff alleges, and has proved, he has an exclusive property, which he asserts the defendant has used, and which the defendant denies?

The first claim is for an improved Hopperboy, which the plaintiff insists is granted by his patent, which has received the sanction of the Supreme Court; and which the defendant acknowledges. This being, then, conceded ground, the Court will proceed to examine it; and the inquiry will be, whether the plaintiff is entitled to a verdict for an mfringement of his patent for his improved Hopperboy. The objection relied upon by the defendant is, that the plaintiff has, not set forth in his specification what are the improvements of which he claims to be