It is much more difficult to obtain the extension of a patent which is about to oxpire, than to procure a patent for a new invention. In the former case the law presupposes that the patentee has received a proper reward for his invention ; in the latter the patent is granted to assist him in obtaining a reward. The applicant for an extension must show to the Commissioner of Patents that the invention is of value ; that he has faithfully endeavored to introduce it to the public ; and that without any negleet on his part, he had failed to receive an adequate remuneration for the time, labor, and ingenuity expended. The rules of the Patent Office require that carefully-prepared statements, with proofs on these points, shall be presented to the Commissioner, who takes nothing for granted. An example of the failures to observe the rules, sometimes made by applicants for extensions, resulting in the loss of thtir cases, is seen in the following official decision : PAPEK-CUTTINS MACHINES (extension).—M. Riehl, August 27, 1869.—The applicant has fallen into a fatal error in making up his accounts, which renders it useless to consider the merits of his case on other points. He first brings down his account to 1837. Previous to that time ho had disbursed Sj87,-00 on account of his invention, and had recjh-e.1 the s a: ? ; anourit in mousy, besides $39,000 in old machines received in exchange for his own. Upon these machines he expended $7,000, and sold them afterward for $40,000. Deducting from the latter sum the estimated value of the old machines, and the expenditures upon them, $32,000 in all, he credits the invention with the balance, $8,000. He also credits it with QUO. being the profits made on new machines since 1887, besides $3,000, old iron on hand. The whole amount of the three latter sums, $10,840, is all, therefore, that he admits himself to have ever received on account of his invention. By a very moderate estimate he shows it to have been worth to the public $40,000, and relies upon this showing as entitling him to an extension. It seems not to have occurred to him that the old machines he received previous to 1807 were also clear gain, and that the invention should be charged with the sum for which he sold them, $10,003, deducting the $7,009 he expended upon them. He should, in fact, have allowed their estimated value, $25,000, in addition to the sum he credited. $10,840, making $35,840 which he has received over and above all expenditures. This approaches so near to the supposed value of the invention as to destroy his claim to a further monopoly. There is reason to believe that the applicant might with propriety have made a far more favorable exhibit of his case had he not fallen into a delusion by his manner of presenting his accounts. An opportunity was offered him, accordingly, to explain and correct them. Unfortunately, he was so situated as to be unable to prepare them anew. It is out of the Commissioner's power to remedy the mistake, and he is left without any ground for finding that the petitioner has not been pretty nearly remunerated for his ingenuity, time, and expense. The patent cannot be extended. S. H. HODGES, Acting Commissioner.