delivered the opinion of the Court:

This is an interference proceeding between opposing applicants Charlie Mark and John E. Greenawalt, for a patent for a process of subjecting materials to the action of air and other gases. The process is practised by the introduction of air or other oxygen containing gas through the porous bed or hearth of a reverberatory furnace.

While an interference was depending between the same parties an application for patents for an improvement in furnaces adapted to the use of the process, Mark applied for this process patent, and the same was issued to him May 19, 1903. On January 26, 1904, Greenawalt filed a division of the application for his apparatus invention, and this interference was declared between them, on the process claims. Both parties relied on their apparatus applications as constructive reductions to practice, and, as Mark’s was the earlier one, the burden was upon Greenawalt. He attacked the operativeness of Mark’s apparatus. No tests of the same had then been made by either party. The Examiner of Interferences decided ill at Mark’s apparatus was apparently operative, and awarded priority to him. On appeal to the Examiners-in-Chief, this decision was affirmed save as to counts 6 and 7 of the issue, of the possession of the invention of which it was said that Mark had no evidence prior to the disclosure of Greenawalt’s application. Mark did not' appeal from any part of that decision, but Greenawalt did.

The appeal was heard by the Commissioner with the later ap*269peal of Mark from tlie decision of the Examiners-in-Chief in the interference proceeding relating to the apparatus. The evidence in that case of the tests of the Mark furnace, made in February, 1906, was, by stipulation, considered in this one. There was a practical consolidation of the two cases, but a separate decision was made in each, and separate appeals were taken in each case to this court. The Commissioner, having decided that the tests •of Mark’s furnace demonstrated its inoperativeness, awarded priority in that case to Greenawalt. Holding that that determination removed the foundation of Mark’s claim of that application as a constructive reduction to practice of the process invention, he reversed the decision in favor of Mark, and awarded priority to Greenawalt in this case also. The appeals numbered, respectively, in this court, as 506 and 507, were submitted together as they had been to the Commissioner. Having reversed the Commissioner’s decision holding that Mark’s apparatus was inoperative, in No. 507, \ante, p. 253] it follows that his decision in this case must also be reversed. It is so ordered, and that this decision be certified to the Commissioner of Patents as required by law. • Reversed.