Appellant’s conviction of perj'ury was affirmed by this court in Christoffel v. United States, 84 U.S.App.D.C. 132, 171 F.2d 1004, but reversed by the Supreme Court, 338 U.S. 84, 69 S.Ct. 1447, 93 L.Ed. 1826. Upon retrial appellant was again convicted and we affirmed, 91 U.S. App.D.C. 241, 200 F.2d 734. He again petitioned the Supreme Court for a writ of certiorari. Without briefs on the ., , ,, „ „ , merits or argument the Supreme Court . . . . . 1 , , m a single per curiam order granted cer- . . , ,, . , , . . tioran, vacated the judgment of this . ’ , , ,, , ,, court and remanded the case to the District Court for resentencing under 18 U.S.C. § 231 (1946). 1 Christoffel v. United States, 345 U.S. 947, 73 S.Ct. 868, 97 L.Ed. 1371. This was done. Chris-toffel again appeals, raising questions not connected with the resentencing which occurred pursuant to the mandate of the Supreme Court, but directed to the earlier District Court proceedings which preceded our decision in 91 U.S.App.D.C. 241, 200 F.2d 734.

The Government urges that since the mandate of the Supreme Court required, jn addition to vacation of our j'udgment, only resentencing of Christoffel by the District Court, we are without jurisdiction on the present appeal to consider questions unrelated to the resentencing itself.

We may not review action taken as required by a mandate of the _ ,, Supreme Court. It is for that Court to ... , . . „ . construe its own mandate as to all mat- , , , T c „ , ters encompassed by it. In re Sanford Fork & Tool Co. 160 U.S. 247, 255-256, 16 S.Ct 291, 40 L.Ed. 414; Gaines v. Rugg, 148 U.S. 228, 238, 13 S.Ct. 611, 37 L.Ed. 432; Ohio Oil Co. v. Thompson, 8 Cir., 120 F.2d 831, certiorari denied, 314 U.S. 658, 62 S.Ct. 112, 86 L.Ed. 528. But the mandate is controlling only as to matters within its compass. Lower courts are free as to other matters over which they have jurisdiction. Sprague v. Ticonic Nat. Bank, 307 U.S. 161, 168, 59 S.Ct. 777, 83 L.Ed. 1184; In re Sanford Fork & Tool Co., supra; Mason v. *267 Pewabic Mining Company, 153 U.S. 361, 14 S.Ct. 847, 38 L.Ed. 745; Illinois Bell Telephone Co. v. Slattery, 7 Cir., 98 F.2d 930; Id., 7 Cir., 102 F.2d 58, certiorari denied, 307 U.S. 648, 59 S.Ct. 1045, 83 L.Ed. 1527; Ohio Oil Co. v. Thompson, supra.

The Supreme Court mandate here pro-jd d.

“ * * * It is ordered and adjudged by this Court that the judgment of the said United States Court of Appeals, in this cause, be, and the same is hereby, vacated; and that this cause be, and the same is hereby, remanded to the United States District Court for the District of Columbia for resentencing under 18 U.S.C. (1946 Ed.), Sec. 231.”

As stated, we are not asked to review the resentence as such, but only alleged errors relating to the conviction. If, however, we were to act favorably to appellant on any of his contentions, the consequence would be to reverse or set aside the sentence. For it constitutes the judgment from which the appeal is taken. Because of this it may be argued that we are powerless to en- , , . ,, , . . , tertam questions the resolution of which might entail the setting aside of action of the District Court taken in strict accordance with the mandate of the Supreme Court. But we do not think this is a true appraisal of the legal situation. It does not appear from its per curiam order that the Supreme Court reviewed in a definitive manner errors asserted to have occurred during the trial. It might not have been thought a case which required full consideration by the Supreme Court, though the sentence itself must be imposed under the applicable statute. In these circumstances we do not think the mandate is to be construed so as to dePríve US °f jurisdiction over matters not m reality embraced m the resentencing itself or in the mandate which preceded it. 2 We have jurisdiction to review errors said to undermine a conviction, and consequent sentence, notwithstanding we had already done so on a prior appeal.2 3 See Fletcher v. United states, 42 App.D.C. 511, certiorari denied, 235 U.S. 706, 35 S.Ct. 283, 59 L.Ed. 434. We are asked, in substance, to grant a rehearing of appellant’s appeal, This we have jurisdiction to do; otherwise errors which go to the validity of a judgment based upon a conviction might be left uncorrected, inconsistent with sucb provisions as 28 U.S.C. § 2255, perniitting even collateral attack, though on limited grounds.

\ye nevertheless affirm. The questions now pressed are untime!y. The cage bag been gubmitted twice be_ fore tQ thig Qn al and on ti_ ,. * , , , , , « tion for rehearing, and has been before ,. ~ ^ A .. the S"preme Court In ™ of ^ese breedings was any one of the matters now P^ented asserted as error. Upon examining each of them we conclude that *n ^bese circumstances none constitutes the kind of error which we ou^ht now to eonsi<ier.

Affirmed.