trial of all issues so demanded shall be by jury, unless (1) the parties or their attorneys of record, by written stipulation filed with the court or by an oral stipulation made in open court and entered in the record, consent to trial by the court sitting without a jury or (2) the court upon motion or of its own initiative finds that a right of trial by jury of some or all of those issues does not exist under the Constitution or statutes of the United States.

(b) BY THE COURT. Issues not demanded for trial by jury as provided in Rule 38 shall be tried by the court; but, notwithstanding the failure of a party to demand a jury in an action in which such a demand might have been made of right, the court in its discretion upon motion may order a trial by a jury of any or all issues.

(c) ADVISORY JURY AND TRIAL BY CONSENT. In all actions not triable of right by a jury the court upon motion or of its own initiative may try any issue with an advisory jury or, except in actions against the United States when a statute of the United States provides for trial without a jury, the court, with the consent of both parties, may order a trial with a jury whose verdict has the same effect as if trial by jury had been a matter of right.

Rule 40. Assignment of Cases for Trial. The district courts shall provide by rule for the placing of actions upon the trial calendar (1) without request of the parties or (2) upon request of a party and notice to the other parties or (3) in such other manner as the courts deem expedient. Precedence shall be given to actions entitled thereto by any statute of the United States.

Rule 41. Dismissal of Actions.
(a) VOLUNTARY DISMISSAL: EFFECT THEREOF.

(1) By Plaintiff; By Stipulation. Subject to the provisions of Rule 23 (c) and of any statute of the United States, an action may be dismissed by the plaintiff without order of court (i) by filing a notice of dismissal at any time before service of the answer or (ii) by filing a stipulation of dismissal signed by all the parties who have appeared generally in the action. Unless otherwise stated in the notice of dismissal or stipulation, the dismissal is without prejudice, except that a notice of dismissal operates as an adjudication upon the merits when filed by a plaintiff who has once dismissed in any court of the United States or of any state an action based on or including the same claim.

(2) By Order of Court. Except as provided in paragraph (1) of this subdivision of this rule, an action shall not be dismissed at the plaintiff's instance save upon order of the court and upon such terms and conditions as the court deems proper. If a counterclaim has been pleaded by a defendant prior to the service upon him of the plaintiff's motion to dismiss, the action shall not be dismissed against the defendant's objection unless the counterclaim can remain pending for independent adjudication by the court. Unless otherwise specified in the order, a dismissal under this paragraph is without prejudice.

(b) INVOLUNTARY DISMISSAL: EFFECT THEREOF. For failure of the plaintiff to prosecute or to comply with these rules or any order of court, a defendant may move for dismissal of an action or of any claim against him. After the plaintiff has completed the presentation of his evidence, the defendant, without

waiving his right to offer evidence in the event the motion is not granted, may move for a dismissal on the ground that upon the facts and the law the plaintiff has shown no right to relief. Unless the court in its order for dismissal otherwise specifies, a dismissal under this subdivision and any dismissal not provided for in this rule, other than a dismissal for lack of jurisdiction or for improper venue, operates as an adjudication upon the merits.

(c) DISMISSAL OF COUNTERCLAIM, CROSS-CLAIM, OR THIRD-PARTY CLAIM. The provisions of this rule apply to the dismissal of any counterclaim, crossclaim, or third-party claim. A voluntary dismissal by the claimant alone pursuant to paragraph (1) of subdivision (a) of this rule shall be made before a responsive pleading is served or, if there is none, before the introduction of evidence at the trial or hearing.

(d) COSTS OF PREVIOUSLY-DISMISSED ACTION. If a plaintiff who has once dismissed an action in any court commences an action based upon or including the same claim against the same defendant, the court may make such order for the payment of costs of the action previously dismissed as it may deem proper and may stay the proceedings in the action until the plaintiff has complied with the order.

Rule 42. Consolidation; Separate Trials.

(a) CONSOLIDATION. When actions When actions involving a common question of law or fact are pending before the court, it may order a joint hearing or trial of any or all the matters in issue in the actions; it may order all the actions consolidated; and it may make such orders concerning proceedings therein as may tend to avoid unnecessary costs or delay.

(b) SEPARATE TRIALS. The court in furtherance of convenience or to avoid prejudice may order a

separate trial of any claim, cross-claim, counterclaim, or third-party claim, or of any separate issue or of any number of claims, cross-claims, counterclaims, third-party claims, or issues.

Rule 43. Evidence.

(a) FORM AND ADMISSIBILITY. In all trials the testimony of witnesses shall be taken orally in open court, unless otherwise provided by these rules. All evidence shall be admitted which is admissible under the statutes of the United States, or under the rules of evidence heretofore applied in the courts of the United States on the hearing of suits in equity, or under the rules of evidence applied in the courts of general jurisdiction of the state in which the United States court is held. In any case, the statute or rule which favors the reception of the evidence governs and the evidence shall be presented according to the most convenient method prescribed in any of the statutes or rules to which reference is herein made. The competency of a witness to testify shall be determined in like manner.

(b) SCOPE OF EXAMINATION AND CROSS-EXAMINATION. A party may interrogate any unwilling or hostile witness by leading questions. A party may call an adverse party or an officer, director, or managing agent of a public or private corporation or of a partnership or association which is an adverse party, and interrogate him by leading questions and contradict and impeach him in all respects as if he had been called by the adverse party, and the witness thus called may be contradicted and impeached by or on behalf of the adverse party also, and may be crossexamined by the adverse party only upon the subject matter of his examination in chief.

(c) RECORD OF EXCLUDED EVIDENCE. In an action tried by a jury, if an objection to a question

propounded to a witness is sustained by the court, the examining attorney may make a specific offer of what he expects to prove by the answer of the witness. The court may require the offer to be made out of the hearing of the jury. The court may add such other or further statement as clearly shows the character of the evidence, the form in which it was offered, the objection made, and the ruling thereon. In actions tried without a jury the same procedure may be followed, except that the court upon request shall take and report the evidence in full, unless it clearly appears that the evidence is not admissible on any ground or that the witness is privileged.

(d) AFFIRMATION IN LIEU OF OATH. Whenever under these rules an oath is required to be taken, a solemn affirmation may be accepted in lieu thereof.

(e) EVIDENCE ON MOTIONS. When a motion is based on facts not appearing of record the court may hear the matter on affidavits presented by the respective parties, but the court may direct that the matter be heard wholly or partly on oral testimony or depositions.

Rule 44. Proof of Official Record.

(a) AUTHENTICATION OF COPY. An official record or an entry therein, when admissible for any purpose, may be evidenced by an official publication thereof or by a copy attested by the officer having the legal custody of the record, or by his deputy, and accompanied with a certificate that such officer has the custody. If the office in which the record is kept is within the United States or within a territory or insular possession subject to the dominion of the United States, the certificate may be made by a judge of a court of record of the district or political subdivision in which the record is kept, authenticated