On December 3, 1954, taxpayer, Kutner, and counsel for the Commissioner filed with the Tax Court a stipulation that deficiencies and penalty in a certain amount were owing from taxpayer for 1949 and 1950. Based upon this stipulation the Tax Court entered decision for the amount of the deficiencies and penalty agreed upon. The decision of the Tax Court was entered on December 6, 1954, and served December 8, 1954. The time within which to file a petition for review by the Court of Appeals expired March 6, 1955 and, no petition for review having been filed, the decision of the Tax Court became final. Taxpayer filed with the Tax Court, on August 1, 1956, a motion to vacate the order nunc pro tunc and for a reconsideration of the decision dated December 6, 1954. Upon denial by the Tax Court of that motion, August 22, 1956, taxpayer petitioned for review by this Court. This taxpayer insisted in his motion, and before our court, that a gross injustice had been done owing to facts becoming known subsequent to the December 1954 order and stipulation. The alleged deprivation of justice asserted by this taxpayer, confers no jurisdiction upon the Tax Court, after its decision of December 6, 1954 became final to further consider this case. Internal Revenue Code of 1954, § 7481, 26 U.S.C. § 7481 (Supp. II, 1952 ed.). Finality and timeliness are twin prongs of the Tax Court's power circumscribed by the relevant Code provision. Lasky v. Commissioner, 9 Cir., 1956, 235 F.2d 97, affirmed 1957, 352 U.S. 1027, 77 S. Ct. 594, 1 L. Ed. 2d 598; Lentin v. Commissioner, 7 Cir., 243 F.2d 907.