opinion: COLGROVE v. BATTIN, U. S. DISTRICT JUDGE
  No. 71-1442.
  Argued January 17, 1973 —
  Decided June 21, 1973
  BrennaN, J., delivered the opinion of the Court, in which Burger, C. J., and White, BlackmuN, and RehNquist, JJ., joined. Douglas, J., filed a dissenting opinion, in which Powell, J., joined, post, p. 165. Marshall, J., filed a dissenting opinion, in which Stewart, J., joined, post, p. 166. Powell, J., filed a dissenting opinion, post, p. 188.
  Lloyd J. Skedd argued the cause and filed a brief for petitioner.
  Cále Crowley argued the cause and filed a brief for respondent.
  Briefs of amici curiae were filed by William A. Wick, Alston Jennings, and John C. Elam for the International Association of Insurance Counsel; by Joseph W. Cotchett, David Daar, Leonard Sacks, Siegfried Hesse, Edward I. Pollock, Theodore A. Horn, and Marvin E. Lewis for the California Trial Lawyers Assn.; by Leonard Boudin and Alan Scheflin for the National Emergency Civil Liberties Committee; and by the Nooter Corp.
  Mr. Justice Brennan
  delivered the opinion of the Court.
  Local Rule 13(d)(1) of the Revised Rules of Procedure of the United States District Court for the District of Montana provides that a jury for the trial of civil cases shall consist of six persons. When respondent District Court Judge set this diversity case for trial before a jury of six in compliance with the Rule, petitioner sought mandamus from the Court of Appeals for the Ninth Circuit to direct respondent to impanel a 12-mem-ber jury. Petitioner contended that the local Rule (1) violated the Seventh Amendment; (2) violated the statutory provision, 28 U. S. C. § 2072, that rules “shall preserve the right of trial by jury as at common law and as declared by the Seventh Amendment . . and (3) was rendered invalid by Fed. Rule Civ. Proc. 83 because “inconsistent with” Fed. Rule Civ. Proc. 48 that provides for juries of less than 12 when stipulated by the parties. The Court of Appeals found no merit in these contentions, sustained the validity of local Rule 13 (d) (1), and denied the writ, 456 F. 2d 1379 (1972). We granted certiorari, 409 U. S. 841 (1972). We affirm.
  I
  In Williams v. Florida, 399 U. S. 78 (1970), the Court sustained the constitutionality of a Florida statute providing for six-member juries in certain criminal cases. The constitutional challenge rejected in that case relied on the guarantees of jury trial secured the accused by Art. Ill, § 2, cl. 3, of the Constitution and by the Sixth Amendment. We expressly reserved, however, the question whether “additional references to the 'common law’ that occur in the Seventh Amendment might support a different interpretation” with respect to jury trial in civil cases. Id., at 92 n. 30. We conclude that they do not.
  The pertinent words of the Seventh Amendment are: “In Suits at common law . . . the right of trial by jury shall be preserved ...” On its face, this language is not directed to jury characteristics, such as size, but rather defines the kind of cases for which jury trial is preserved, namely, “suits at common law.” And while it is true that “[w]e have almost no direct evidence concerning the intention of the framers of the seventh amendment itself,” the historical setting in which the Seventh Amendment was adopted highlighted a controversy that was generated, not by concern for preservation of jury characteristics at common law, but by fear that the civil jury itself would be abolished unless protected in express words. Almost a century and a half ago, this Court recognized that “[o]ne of the strongest objections originally taken against the constitution of the United States, was the want of an express provision securing the right of trial by jury in civil cases.” Parsons v. Bedford, 3 Pet. 433, 445 (1830). But the omission of a protective clause from the Constitution was not because an effort was not made to include one. On the contrary, a proposal was made to include a provision in the Constitution to guarantee the right of trial by jury in civil cases but the proposal failed because the States varied widely as to the cases in which civil jury trial was provided, and the proponents of a civil jury guarantee found too difficult the task of fashioning words appropriate to cover the different state practices. The strong pressures for a civil jury provision in the Bill of Rights encountered the same difficulty. Thus, it was agreed that, with no federal practice to draw on and since state practices varied so widely, any compromising language would necessarily have to be general. As a result, although the Seventh Amendment achieved the primary goal of jury trial adherents to incorporate an explicit constitutional protection of the right of trial by jury in civil cases, the right was limited in general words to “suits at common law.” We can only conclude, therefore, that by referring to the “common law,” the Framers of the Seventh Amendment were concerned with preserving the right of trial by jury in civil cases where it existed at common law, rather than the various incidents of trial by jury. In short, what was said in Williams with respect to the criminal jury is equally applicable here: constitutional history reveals no intention on the part of the Framers “to equate the constitutional and common-law characteristics of the jury.” 399 U. S., at 99.
  Consistently with the historical objective of the Seventh Amendment, our decisions have defined the jury right preserved in cases covered by the Amendment, as “the substance of the common-law right of trial by jury, as distinguished from mere matters of form or procedure . . . .” Baltimore & Carolina Line, Inc. v. Redman, 295 U. S. 654, 657 (1935). The Amendment, therefore, does not “bind the federal courts to the exact procedural incidents or details of jury trial according to the common law in 1791,” Galloway v. United States, 319 U. S. 372, 390 (1943); see also Ex parte Peterson, 253 U. S. 300, 309 (1920); Walker v. New Mexico & S. P. R. Co., 165 U. S. 593, 596 (1897), and “[n]ew devices may be used to adapt the ancient institution to present needs and to make of it an efficient instrument in the administration of justice. . ..” Ex parte Peterson, supra, at 309-310; Funk v. United States, 290 U. S. 371, 382 (1933).
  Our inquiry turns, then, to whether a jury of 12 is of the substance of the common-law right of trial by jury. Keeping in mind the purpose of the jury trial in criminal cases to prevent government oppression, Williams, 399 U. S., at 100, and, in criminal and civil cases, to assure a fair and equitable resolution of factual issues, Gasoline Products Co. v. Champlin Co., 283 U. S. 494, 498 (1931), the question comes down to whether jury performance is a function of jury size. In Williams, we rejected the no-, tion that “the reliability of the jury as a factfinder . . . [is] a function of its size,” 399 U. S., at 100-101, and nothing has been suggested to lead us to alter that conclusion. Accordingly, we think it cannot be said that 12 members is a substantive aspect of the right of trial by jury.
  It is true, of course, that several earlier decisions of this Court have made the statement that “trial by jury” means “a trial by a jury of twelve ....” Capital Traction Co. v. Hof, 174 U. S. 1, 13 (1899); see also American Publishing Co. v. Fisher, 166 U. S. 464 (1897); Maxwell v. Dow, 176 U. S. 581, 586 (1900). But in each case, the reference to “a jury of twelve” was clearly dictum and not a decision upon a question presented or litigated. Thus, in Capital Traction Co. v. Hof, supra, the case most often cited, the question presented was whether a civil action brought before a justice of the peace of the District of Columbia was triable by jury, and. that question turned on whether the justice of the peace was a judge empowered to instruct them on the law and advise them on the facts. Insofar as the Hof statement implied that the Seventh Amendment required a jury of 12, it was at best an assumption. And even if that assumption had support in common-law doctrine, our canvass of the relevant constitutional history, like the history canvassed in Williams concerning the criminal jury, "casts considerable doubt on the easy assumption in our past decisions that if a given feature existed in a jury at common law . . . then it was necessarily preserved in the Constitution.” 399 U. S., at 92-93. We cannot, therefore, accord the unsupported dicta of these earlier decisions the authority of decided precedents.
  There remains, however, the question whether a jury of six satisfies the Seventh Amendment guarantee of “trial by jury.” We had no difficulty reaching the conclusion in Williams that a jury of six would guarantee an accused the trial by jury secured by Art. Ill and the Sixth Amendment. Significantly, our determination that there was "no discernible difference between the results reached by the two different-sized juries,” 399 U. S., at 101, drew largely upon the results of studies of the operations of juries of six in civil cases. Since then, much has been written about the six-member jury, but nothing that persuades us to depart from the conclusion reached in Williams. Thus, while we express no view as to whether any number less than six would suffice, we conclude that a jury of six satisfies the Seventh Amendment's guarantee of trial by jury in civil cases.
  II
  The statute, 28 U. S. C. § 2072, authorizes this Court to promulgate the Federal Rules of Civil Procedure but provides that “[s]uch rules . . . shall preserve the right of trial by jury as at common law and as declared by the Seventh Amendment to the Constitution.” Petitioner argues that in securing trial by jury “as at common law” and also “as declared by the Seventh Amendment,” Congress meant to provide a jury having the characteristics of the common-law jury even if the Seventh Amendment did not require a jury with those characteristics. As the Court of Appeals observed, “[t]his would indeed be a sweeping limitation.” 456 F. 2d, at 1380. Petitioner would impute to Congress an intention to saddle archaic and presently unworkable common-law procedures upon the federal courts and thereby to nullify innovative changes approved by this Court over the years that have now become commonplace and, for all practical purposes, “essential to the preservation of the right” of trial by jury in our modern society. Ex parte Peterson, 253 U. S., at 310; Galloway v. United States, 319 U. S., at 390-391. For to say that Congress chose this means to render our system of civil jury trial immutable as of 1791, or some other date, is to say the Congress meant to deny the judiciary the “flexibility and capacity for growth and adaptation [which] is the peculiar boast and excellence of the common law.” Hurtado v. California, 110 U. S. 516, 530 (1884); Funk v. United States, 290 U. S., at 382.
  But petitioner’s extravagant contention has not the slightest support in the legislative history of the provision. Section 2072 is derived from the Enabling Act of 1934, 48 Stat. 1064. Section 2 of that Act gave this Court the “power to unite the general rules prescribed ... for cases in equity with those in actions at law so as to secure one form of civil action and procedure for both.” H. R. Rep. No. 1829, 73d Cong., 2d Sess., 1 (1934). As emphasized by the Court of Appeals, the language of § 2 preserving the right of trial by jury was included “to assure that with such union [of law and equity] the right of trial by jury would be neither expanded nor contracted.” 456 F. 2d, at 1381, citing 5 J. Moore, Federal Practice ¶ 38.06, p. 44 (2d ed. 1971). See also Cooley v. Strickland Transportation Co., 459 F. 2d 779, 785 (CA5 1972). In other words, Congress used the language in question for the sole purpose of creating a statutory right coextensive with that under the Seventh Amendment itself. If Congress had meant to prescribe a jury number or to legislate common-law features generally, "it knew how to use express language to that effect.” Williams v. Florida, 399 U. S., at 97.
  Ill
  Petitioner’s argument that local Rule 13 (d)(1) is inconsistent with Fed. Rule Civ. Proc. 48 rests on the proposition that Rule 48 implies a direction to impanel a jury of 12 in the absence of a stipulation of the parties for a lesser number. Rule 48 was drafted at the time the statement in Capital Traction Co. v. Hoj, supra, that trial by jury means a “jury of twelve,” was generally accepted. Plainly the assumption of the draftsmen that such was the case cannot be transmuted into an implied direction to impanel juries of 12 without regard to whether a jury of 12 was required by the Seventh Amendment. Our conclusion that the Hoj statement lacks prec-edential weight leaves Rule 48 without the support even of the draftsmen’s assumption and thus there is nothing in the Rule with which the local Rule is inconsistent. See Cooley v. Strickland Transportation Co., supra, at 783-785; Devitt, The Six Man Jury in the Federal Court, 53 F. R. D. 273, 274 n. 1 (1971).
  Similarly, we reject the argument that the local Rule conflicts with Rule 48 because it deprives petitioner of the right to stipulate to a jury of “any number less than twelve.” Aside from the fact that there is no indication in the record that petitioner ever sought a jury of less than 12, Rule 48 “deals only with a stipulation by ‘[t]he parties.’ It does not purport to prevent court rules which provide for civil juries of reduced size.” Cooley v. Strickland Transportation Co., supra, at 784.
  Affirmed.
  Rule 13(d)(1) provides:
  "A jury for the trial of civil cases shall consist of six persons plus such alternate jurors as may be impaneled.”
  Similar local rules have been adopted by 54 other federal district courts, at least as to some civil cases. See the appendix to Fisher, The Seventh Amendment and the Common Law: No Magic in Numbers, 56 F. R. D. 507, 535-542 (1973) (the District Court of Delaware has since adopted a rule effective January 1, 1973). In addition, two bills were introduced in the 92d Congress to reduce to six the number of jurors in all federal civil cases. H. R. 7800, 92d Cong., 1st Sess. (1971); H. R. 13496, 92d Cong., 2d Sess. (1972). H. R. 7800, insofar as it related to civil juries, has received the approval of the Committee on the Operation of the Jury System of the Judicial Conference of the United States. 1971 Annual Report of the Director of the Administrative Office of the United States Courts 41. That Conference itself at its March 1971 meeting endorsed “in principle” a reduction in the size of civil juries. Ibid.
  The Seventh Amendment provides :
  “In Suits at common law, where the value in controversy shall exceed twenty dollars, the right of trial by jury shall be preserved, and no fact tried by a jury, shall be otherwise reexamined in any Court of the United States, than according to the rules of the common law.”
  State court decisions have usually turned on the interpretation of state constitutional provisions. See Ann., 47 A. L. R. 3d 895 (1973).
  Title 28 U. S. C. §2072 provides:
  “The Supreme Court shall have the power to prescribe by general rules, the forms of process, writs, pleadings, and motions, and the practice and procedure of the district courts and courts of appeals of the United States in civil actions ....
  “Such rules shall not abridge, enlarge or modify any substantive right and shall preserve the right of trial by jury as at common law and as declared by the Seventh Amendment to the Constitution.”
  Fed. Rule Civ. Proc. 48 provides:
  “The parties may stipulate that the jury shall consist of any number less than twelve or that a verdict or a finding of a stated majority of the jurors shall be taken as the verdict or finding of the jury.”
  Fed. Rule Civ. Proc. 83 provides:
  “Each district court by action of a majority of the judges thereof may from time to time make and amend rules governing its practice not inconsistent with these rules. ... In all cases not provided for by rule, the district courts may regulate their practice in any manner not inconsistent with these rules.”
  Art. Ill, §2, cl. 3, provides:
  “The Trial of all Crimes, except in Cases of Impeachment, shall be by Jury; and such Trial shall be held in the State where the said Crimes shall have been committed; but when not committed within any State, the Trial shall be at such Place or Places as the Congress may by Law have directed.”
  The Sixth Amendment provides:
  “In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defence.”
  The reference to “common law” contained in the second clause of the Seventh Amendment is. irrelevant to our present inquiry because it deals exclusively with the prohibition contained in that clause against the indirect impairment of the right of trial by jury through judicial re-examination of factfindings of a jury other than as permitted in 1791. Baltimore & Carolina Line, Inc. v. Redman, 295 U. S. 654, 657 (1935); Parsons v. Bedford, 3 Pet. 433, 447-448 (1830); 5 J. Moore, Federal Practice ¶ 38.08 [5], pp. 86-90 (2d ed. 1971).
  Henderson, The Background of the Seventh Amendment, 80 Harv. L. Rev. 289, 291 (1966).
  See 2 M. Farrand, Records of the Federal Convention 587 (1911). See also Henderson, supra, n. 7, at 292-294.
  The question of a provision for the protection of the right to trial by jury in civil eases apparently was not presented at the Constitutional Convention until a proposed final draft of the Constitution was reported out of the Committee on Style and Arrangement. At that point, Mr. Williamson of North Carolina “observed to the House that no provision was yet made for juries in Civil cases and suggested the necessity of it.” 2 Farrand, supra, at 587. This provoked the following discussion:
  “Mr. Gorham. It is not possible to discriminate equity eases from those in which juries are proper. The Representatives of the people may be safely trusted in this matter.
  “Mr. Gerry urged the necessity of Juries to guard [against] corrupt Judges. He proposed that the Committee last appointed should be directed to provide a clause for securing the trial by Juries.
  “Col. Mason perceived the difficulty mentioned by Mr. Gorham. The jury cases cannot be specified. A general principle laid down on this and some other points would be sufficient. He wished the plan had been prefaced with a Bill of Rights, & would second a Motion if made for the purpose . . . .” Ibid.
  Three days later, a proposal was made by Mr. Gerry and Mr. Pinckney to add the following language to the Art. Ill guarantee of trial by jury in criminal cases: “And a trial by jury shall be preserved as usual in civil cases.” This proposal prompted the following reaction:
  “Mr. Gorham. The constitution of Juries is different in different States and the trial itself is usual in different cases in different States.
  “Mr. King urged the same objections.
  “Geni. Pinckney also. He thought such a clause in the Constitution would be pregnant with embarrassments.
  “The motion was disagreed to nem. con.” Id., at 628.
  James Wilson of Pennsylvania defended the omission at the Penn-sylvánia Convention convened to ratify the Constitution:
  “The cases open to a jury, differed in the different states; it was therefore impracticable, on that ground, to have made a general rule. The want of uniformity would have rendered any reference to the practice of the states idle and useless: and it could not, with any propriety, be said, that ‘the trial by jury shall be as heretofore:’ since there has never existed any foederal system of jurisprudence, to which the declaration could relate. Besides, it is not in all cases that the trial by jury is adopted in civil questions: for causes depending in courts of admiralty, such as relate to maritime captures, and such as are agitated in the courts of equity, do not require the intervention of that tribunal. How, then, was the line of discrimination to be drawn? The convention found the task too difficult for them; and they left the business as it stands — in the fullest confidence, that no danger would possibly ensue, since the proceedings of the supreme court are to be regulated by the congress, which is a faithful representation of the people: and the oppression of govern-' ment is effectually barred, by declaring that in all criminal cases, the trial by jury shall be preserved.” 3 M. Farrand, Records of the Federal Convention 101 (1911).
  A proponent of a guarantee responded:
  “The second and most important objection to the federal plan, which Mr. Wilson pretends to be made in a disingenuous form, is the entire abolition of the trial by jury in civil cases. It seems to me that Mr. Wilson’s pretended answer is much more disingenuous than the objection itself .... He says, ‘that the cases open to trial by jury differing in the different States, it was therefore impracticable to have made a general rule.’ This answer is extremely futile, because a reference might easily have been made to the common law of England, which obtains through every State, and cases in the maritime and civil law courts would, of course, be excepted. . . .” Quoted in Henderson, swpra, n. 7, at 296-297. See also 1 J. Elliot, The Debates in the Several State Conventions, on the Adoption of the Federal Constitution (2d ed. 183-6).
  That the words “common law” were used merely to establish a general rule of trial by jury in civil cases was the view of Mr. Justice Story in the discussion in his Commentaries of the Seventh Amendment and the Judiciary Act of 1789:
  “The phrase, 'common law,’ found in this clause, is used in contradistinction to equity, and admiralty, and maritime jurisprudence. The constitution had declared, in the third article, 'that the judicial power shall extend to all cases in law and equity arising under this constitution, the laws of the United States, and treaties made, or which shall be made under their authority,’ &c., and 'to all cases of admiralty and maritime jurisdiction.’ It is well known, that in civil causes, in courts of equity and admiralty, juries do not intervene; and that courts of equity use the trial by jury only in extraordinary cases to inform the conscience of the court. When, therefore, we find, that the amendment requires, that the right of trial by jury shall be preserved in suits at common law, the natural conclusion is, that the distinction was present to the minds of the framers of the amendment. By common law they meant, what the constitution denominated in the third article ‘law’ .... And congress seem to have acted with reference to this exposition in the judiciary act of 1789, ch. 20, (which was contemporaneous with the proposal of this amendment;) . . . .” 3 J. Story, Commentaries on the Constitution of the United States 645-646 (1833).
  Constitutional history does not reveal a single instance where concern was expressed for preservation of the traditional number 12. Indeed, James Wilson of Pennsylvania, a member of the Constitutional Convention and later a Justice of this Court, stated: “When I speak of juries, I feel no peculiar predilection for the number twelve . . . 2 The Works of James Wilson 503 (R. McCloskey ed. 1967).
  See also Scott, Trial by Jury and the Reform of Civil Procedure, 31 Harv. L. Rev. 669, 671 (1918):
  “Although the incidents of trial by jury which existed at the time of the adoption of the constitutional guaranty are not thereby abolished, yet those incidents are not necessarily made unalterable. Only those incidents which are regarded as fundamental, as inherent in and of the essence of the system of trial by jury, are placed beyond the reach of the legislature. The question of the constitutionality of any particular modification of the law as to trial by jury resolves itself into a question of what requirements are fundamental and what are unessential, a question which is necessarily, in the last analysis, one of degree. The question, it is submitted, should be approached in a spirit of open-mindedness, of readiness to accept any changes which do not impair the fundamentals of trial by jury. It is a question of substance, not of form.”
  Although Williams proceeded on the premise that the common-law jury was composed of 12 members, juries of less than 12 were common in this country throughout colonial times. See the cases and statutes cited in Fisher, supra, n. 1, at 529-532.
  See Devitt, The Six Man Jury in the Federal Court, 53 F. R. D. 273, 274 (1971); Augelli, Six-Member Juries in Civil Actions in the Federal Judicial System, 3 Seton Hall L. Rev. 281, 285 (1972) ; Croake, Memorandum on the Advisability and Constitutionality of Six Man Juries and 5/6 Verdicts in Civil Cases, 44 N. Y. State B. J. 385 (1972). See also Leger v. Westinghouse Electric Corp., 54 F. R. D. 574 (WD La. 1972); contra, Winsby v. John Oster Mfg. Co., 336 F. Supp. 663 (WD Pa. 1972).
  Williams v. Florida, 399 U. S. 78, 101 n. 48 (1970).
  Arguments, pro and con, on the effectiveness of a jury of six compared to a jury of 12 will be found in Devitt, supra, n. 13; Augelli, supra, n. 13; Croake, supra, n. 13; Fisher, supra, n. 1; Bogue & Fritz, The Six-Man Jury, 17 S. D. L. Rev. 285 (1972); Moss, The Twelve Member Jury in Massachusetts — Can it be Reduced?, 56 Mass. L. Q. 65 (1971); Zeisel, . . . And Then There Were None: The Diminution of the Federal Jury, 38 U. Chi. L. Rev. 710 (1971) ; Zeisel, The Waning of the American Jury, 58 A. B. A. J. 367 (1972) ; Gibbons, The New Minijuries: Panacea or Pandora's Box?, 58 A. B. A. J. 594 (1972); Kaufman, The Harbingers of Jury Reform, 58 A. B. A. J. 695 (1972); Whalen, Remarks on Resolution of 7th Amendment Jury Trial Requirement, 54 F. R. D. 148 (1972); Note, Right to Twelve-Man Jury, 84 Harv. L. Rev. 165 (1970); Note, Reducing the Size of Juries, 5 U. Mich. J. L. Reform 87 (1971); Note, The Effect of Jury Size on the Probability of Conviction: An Evaluation of Williams v. Florida, 22 Case W. Res. L. Rev. 529 (1971); Comment, Defendant’s Right to a Jury Trial — Is Six Enough?, 59 Ky. L. J. 997 (1971).
  Professor Zeisel has suggested that the six-member jury is more limited than the 12-member jury in representing the full spectrum of the community, and this in turn may result in differences between the verdicts reached by the two panels. Zeisel, supra, 38 U. Chi. L. Rev., at 716-719.
  On the other hand, one study suggests that the decrease in the size of the jury from 12 to six is conducive to a more open discussion among the jurors, thereby improving the quality of the deliberative process. Note, supra, 5 U. Mich. J. L. Reform, at 99-106. See also C. Joiner, Civil Justice and the Jury 31, 83 (1962) (concluding prior to Williams that the deliberative process should be the same in either six- or 12-member juries).
  In addition, four very recent studies have provided convincing empirical evidence of the correctness of the Williams conclusion that “there is no discernible difference between the results reached by the two different-sized juries.” Note, Six-Member and Twelve-Member Juries: An Empirical Study of Trial Results, 6 U. Mich. J. L. Reform 671 (1973); Institute of Judicial Administration, A Comparison of Six- and Twelve-Member Civil Juries in New Jersey Superior and County Courts (1972); Note, An Empirical Study of Six- and Twelve-Member Jury Decision-Making Processes, 6 U. Mich. J. L. Reform 712 (1973); Bermant & Coppock, Outcomes of Six- and Twelve-Member Jury Trials: An Analysis of 128 Civil Cases in the State of Washington, 48 Wash. L. Rev. 593 (1973).
  What is required for a “jury” is a number large enough to facilitate group deliberation combined with a likelihood of obtaining a representative cross section of the community. Williams v. Florida, 399 U. S., at 100. It is undoubtedly true that at some point the number becomes too small to accomplish these goals, but, on the basis of presently available data, that cannot be concluded as to the number six. See Tamm, A Proposal for Five-Member Civil Juries in the Federal Courts, 50 A. B. A. J. 162 (1964); Tamm, The Five-Man Civil Jury: A Proposed Constitutional Amendment, 51 Geo. L. J. 120 (1962).
  My Brother Marshall argues in dissent that the various incidents of trial by jury as they existed at common law are immutably saved by the Seventh Amendment's use of the word “preserved.” But obviously the Amendment commands only that the right of trial by jury be “preserved.” Since a jury of 12 is, as has been shown, not of the substance of the common-law right of trial by jury and since there is “no discernible difference between the results reached by the two different-sized juries,” Williams v. Florida, supra, at 101, the use of a six-member civil jury does not impair the right “preserved” by the Seventh Amendment. Indeed, as my Brother Marshall himself recognizes, post, at 179, several devices designed to improve the jury system and unknown to the common law have been approved by this Court over the years. See also Henderson, supra, n. 7; Scott, supra, n. 11. In each case, the determining factor was that the new device did not impair the right preserved by the Seventh Amendment. As Mr. Justice Brandéis aptly stated in response to the argument that a federal court was prevented by the Seventh Amendment from utilizing a special master because it would infringe upon the right of trial by jury:
  “The command of the Seventh Amendment that ‘the right of trial by jury shall be preserved’ . . . does not prohibit the introduction of new methods for determining what facts are actually in issue, nor does it prohibit the introduction of new rules of evidence. Changes in these may be made. New devices may be used to adapt the ancient institution to present needs and to make of it an efficient instrument in the administration of justice. Indeed, such changes are essential to the preservation of the right. The limitation imposed by the Amendment is merely that enjoyment of the right of trial by jury be not obstructed, and that the ultimate determination of issues of fact by the jury be not interfered with.” Ex parte Peterson, 253 U. S. 300, 309-310 (1920).
  Section 2072 is in terms applicable only to the general Federal Rules of Civil Procedure prescribed by this Court. However, 28 U. S. C. § 2071, which authorizes federal district courts to prescribe local rules of practice and procedure, see Part III, infra, requires such rules to be “consistent with Acts of Congress” as well as the general Federal Rules. Thus, if § 2072 prohibits a jury of less than 12, the local rule in question would conflict with an Act of Congress and would therefore be invalid. See 3A W. Barron & A. Holtzoff, Federal Practice and Procedure § 1171, p. 179 (C. Wright ed. 1958).
  See Henderson, supra, n. 7; Scott, supra, n. 11.
  See 5 J. Moore, Federal Practice ¶ 38.06 (2d ed. 1971). The pertinent provisions of the Enabling Act of 1934 were carried forward by the codifying act of 1948, 62 Stat. 961, and later became § 2072 of the Judicial Code, 28 XJ. S. C. § 1 et seq. Section 2072 has been amended several times since 1947, but none of the amendments is relevant to our present discussion.
  Cf. Sibbach v. Wilson & Co., 312 U. S. 1, 10 (1941): “The second [proviso of the Enabling Act of 1934] is that if the rules are to prescribe a single form of action for cases at law and suits in equity, the constitutional right to jury trial inherent in the former must be preserved.”
  This Rule was adopted pursuant to Fed. Rule Civ. Proc. 83, which in turn is derived from 28 U. S. C. § 2071:
  “The Supreme Court and all courts established by Act of Congress may from time to time prescribe rules for the conduct of their business. Such rules shall be consistent with Acts of Congress and rules of practice and procedure prescribed by the Supreme Court.”
  An amicus argues that the local Rule is invalid under our decision in Miner v. Atlass, 363 U. S. 641 (1960). That argument is misplaced. Miner struck down a local rule authorizing discovery-deposition practice in admiralty cases. A court of admiralty had no inherent power, independent of statute or rule, to order the taking of depositions for the purpose of discovery. In 1939, this Court omitted this “basic procedural innovation” from among the Civil Rules adopted as part of the Admiralty Rules. Miner held that this omission “must be taken as an advertent declination of the opportunity to institute the discovery-deposition procedure of Civil Rule 26 (a) throughout courts of admiralty,” id,., at 648, and therefore, for this and additional reasons stated in the opinion, that the local rule “is not consistent with the present General Admiralty Rules . . . .” Id., at 647. In contrast, we hold in this case that Local Rule 13 (d) (1) is not inconsistent with Fed. Rule Civ. Proc. 48.
  Amicus also suggests that Miner should be read to hold that all “basic procedural innovations” are beyond local rulemaking power and are exclusively matters for general rulemaking. We need not consider the suggestion because, in any event, we conclude that the requirement of a six-member jury is not a “basic procedural innovation.” The “basic procedural innovations” to which Miner referred are those aspects of the litigatory process which bear upon the ultimate outcome of the litigation and thus, “though concededly 'procedural,’ may be of as great importance to litigants as many a ‘substantive’ doctrine . . . .” 363 U. S., at 650. Since there has been shown to be “no discernible difference between the results reached by the two different-sized juries,” Williams v. Florida, supra, at 101 (see also n. 15, supra), a reduction in the size of the civil jury from 12 to six plainly does not bear on the ultimate outcome of the litigation.