ply with any of the terms and conditions prescribed by the law for giving a clear and exact description of the invention, and where such failure was due to inadvertence, accident, or mistake, without any fraudulent or deceptive intention. This being shown, a new patent, with a correct specification, was authorized to be issued for the same invention. The act of July 4, 1836, c. 45, enlarged the power to grant reissues by adding an additional ground for reissue; namely, that the patentee had inadvertently claimed in his specification, as his own invention, more than he had a right to claim as new. And, with that addition, the law has continued substantially the same to the present time. The fifty-third section of the act of 1870, c. 230, which'was the law on this subject.when the reissue in the present case was granted, is in the following words: “Whenever any patent is inoperative or invalid by reason of a defective or insufficient specification, or by reason of the patentee claiming as his own invention or discovery more than he had a right to claim as new, if the error has arisen by inadvertence, accident, or mistake, and without any fraudulent or deceptive intention, the commissioner shall, on the surrender of such patent, and the payment of the duty required by law, cause a.new patent for the same invention, and in accordance with the corrected specification, to be issued to the patentee.” It will be observed that whilst the law authorizes a reissue when the patentee has claimed too much, so as to enable him to contract his claim, it does not, in terms, authorize a reissue to enable him to expand his claim. The great object of the law of reissues seems to have been to enable a patentee to make the description, of his invention more clear, plain, and specific, so as to comply with the requirements of the law in that behalf, which were very Comprehensive and exacting. The third section of the act of 179Ó, c. 11, required an applicant for a patent “to deliver a written description of his invention, and of the manner of .using, or process of compounding the same, in such full, clear, and exact terms as to distinguish the same from all other things before known, and to enable any person skilled in the art or science of which it is a branch, or with which it is most nearly connected,' to make, compound, and use the same. And'in the -case of any machine, he shall fully explain the