delivered the opinion of the Court:

On the 24th of August, 1875, Frederick Q. Dubois obtained a patent for: 1, an improvement in the art of making lead traps for plumbers’ use; and, 2, for the improved apparatus therein described, to be used in the manufacture of lead traps for plumbers’ use.

On March 8,1878, he applied for a patent fora plumbers’ trap of soft metal, compressed and seamless, etc., as a new article of manufacture; being the same trap he had claimed was to be produced by the machine or apparatus described in his patent of August, 1875.

The application was rejected on the 13th of March, 1878, by the examiner; again on the 22d of March, again on the 13th of April, 1878, and again on the 15th of February, 1886. In the last ruling the examiner states at large the grounds of his rejection: 1, that the Commissioner, and Judges Ship-man and Wheeler of the United States Courts, had decided that the trap described was not patentable. He refers to the second reason in these terms:

*141“It is unnecessary to mention the numerous decisions which have been rendered of late years, to the effect that the extension of the monopoly, which would result from the granting of a patent for an article which was the necessary product of a machine previously patented, is not provided for by the statute, and. should not be patented.”

This decision, on appeal, was affirmed by the board of examiners in chief; and their ruling, in turn, was approved by the Acting Commissioner.

We have examined carefully all the proceedings in the case, including the several careful arguments made before these successive tribunals, during a litigation of eight years, and that addressed to this Court in the present hearing; but we have found no reason sufficient to induce us to overrule those decisions.

The ruling of the Acting Commissioner is, accordingly, affirmed.