thereupon the said patent shall have the same effect in law as though it had been originally granted for the term of twenty-one years; and the benefit of such renewal shall extend to assignees and grantees of the right to use the thing patented, to the extent of their respective interests therein; Provided, however, That no extension of a patent shall be granted after the expiration of the term for which it was originally issued." [Sect. 18, act 1836, and sect. 1, act 1848.

2. The authority, formerly vested in a Board, to extend patents, having been, by the act of 1848, transferred to the Commissioner of patents, that functionary alone exercises the power in such cases. And in this connection, Justice Story has virtually decided that the decisions of the Commissioner cannot be inquired into and corrected elsewhere. [Woodworth v. Stone, 3 Story's Rep., 789; and Allen v. Blunt, ib., 742.

3. The law [Sect. 12, act 1839,] authorizes the Commissioner to prescribe the rules and regulations for taking testimony in contested cases, of which applications for extending patents (when contested) are among the most important class. These rules and regulations, including depositions, and oaths or affirmations, are the same as are prescribed and required in "Interfering Patents," [see XXII., page 90,]"Appeals," [see XIX., page 88,] &c., &c. They are given in their order. [See "Rules for Taking and Transmitting Evidence to the Commissioner," &c., marked XXVI., page 99, and

"Rules on Extending Patents," marked XXVII., page 101.

4. "As the extension cannot be granted after the patent expires, the application should be made early enough to allow not only for advertising sixty days, but for giving the case due consideration after hearing. Without ample opportunity for

doing this, it cannot be expected that the Commissioner will undertake to decide so important a matter, and grant an extension. He may be bound to receive the application, and act upon it, whenever it is in season for advertising a hearing before the patent expires; but unless he can appoint the day, so as to secure time for deliberation afterward, he will not feel bound to grant it." [Rules of the Patent Office.

5. The applicant must make oath to his statement of receipts and expenditures, as required by law, and witnesses will be examined to show whether or not he has used due diligence in the bringing of his invention into use. And when parties desire to resist the extension, a notice of their intention with a statement of their reasons, should be filed twenty days before the time appointed for the hearing. "They will then be entitled to a copy of the application [for extension] and of the account, [as rendered,] and of any other papers in the case on file. They will also be entitled to a list of the names and residences of the witnesses whose depositions have been taken by the applicant previously, and they must be notified

of the time and place of taking testimony afterward. And they may proceed to take testimony themselves, giving like notice to the applicant." [Rules of the Patent Office.

XXVI. Rules for Taking and Transmitting Evidence to the Commissioner.

1. All statements, declarations, evidence, &c., shall be in writing, setting forth minutely and particularly the point or points at issue, and shall be verified by oath or affirmation.

2. All statements, declarations, proofs, and evidence, shall be filed in the Patent Office by the parties, respectively, before the day of hearing.

3. Before the deposition of a witness or witnesses be taken by either party, notice shall [or should] be given to the opposite party of the time and place when and where such deposition or depositions will be taken, so that the opposite party, either in person or by attorney, shall have full opportunity to cross examine the witness or witnesses. [See "Form of Deposition," marked XXVIII., page 103.] And such notice shall, with proof of service of the same, be attached to the deposition or depositions, whether the party cross examine or not; and such notice shall be given in sufficient time for the appearance of the opposite party, and for the transmission of the evidence to the Patent Office before the day of hearing.

4. No evidence, statement, or declaration, touching the matter at issue, will be considered upon

the said day of hearing, which shall not have been taken and filed in compliance with these rules; provided, that if either party shall be unable, from good and sufficient reasons, to procure the testimony of a witness or witnesses, within the above stipulated time, then it shall be the duty of the said party to give notice of the same to the Commissioner of Patents, accompanied with statements of the cause of such inability, which last mentioned notice to the Commissioner shall be received by him on or before the day of hearing.

5. All evidence, &c., shall be sealed up, and addressed to the Commissioner of Patents, by the persons before whom it shall be taken, and so certified thereon.

6. The certificate of the magistrate taking the evidence, shall be substantially in the following form, and written upon the envelope, viz:

"I hereby certify that the depositions of A. B., C. D., &c., relating to the matter of interference between E. F. and G. H., were taken, sealed up, and addressed to the Commissioner of Patents by ine,

7. The notice of taking testimony should be signed by the party, or the magistrate before whom it is taken, and should contain the names of the witnesses to be examined.

8. It must be served by delivering the adverse party a copy, and exhibiting the original, if he

desires it. If he cannot be found, it may be served upon his agent, or attorney of record in the Patent Office, or by leaving a copy at the party's usual place of business, proof being adduced that it was so left; and it must be annexed to the deposition.

9. The testimony, taken in interrogatories, must be committed to writing by the magistrate, or under his direction, by some one not interested in the issue, nor the agent of one who is. The deposition, when complete, must be signed by the witness.

10. The magistrate must append to the deposition his certificate, stating the time and place of taking it, the names of the witnesses, the administration of the oath, at whose request the testimony is taken, the occasion on which it is intended to be used, and the names of the adverse parties, if any, and whether they were notified and attended.

XXVII. Rules on Extending Patents.

1. The questions which arise on each application for an extension are

(1.) Is the invention novel?

(2.) Is it useful?

(3.) Is it valuable and important to the public? (4.) Has the inventor been adequately remunerated for his time and expense in originating and perfecting it?

(5.) Has he used due diligence in introducing his invention into general use?

2. The first two questions will be determined