This is an appeal by an employee from a decree of the Superior Court dismissing his claim for compensation under the workmen’s compensation law. G. L. (Ter. Ed.) c. 152. The decree conformed to the findings of the reviewing board — the ultimate trier of fact. Those findings superseded the findings more favorable to the employee made by the single member. Di Giovanm’s Case, 255 Mass. 241,242. Seelig’s Case, 280 Mass. 466,467. The burden rested upon the employee to establish the facts essential to entitle him to compensation. Sluzis’s Case, 292 Mass. 351, 355. The reviewing board found that an essential fact was not established. The Superior Court had “no right ... to come to a different conclusion, unless such different conclusion was required as matter of law.” Lazarz’s Case, 293 Mass. 538, 540. Even if, as we do not decide, a different conclusion by the board as a matter of fact would have been warranted by the evidence, clearly such a different conclusion was not as matter of law required by the evidence. The Superior Court, therefore, could not reverse the findings of the reviewing board. And this court cannot do so on appeal.