221 U. S. Argument for Plaintiff in Error. THE facts, which involve the construction of the provisions of the act of March 3, 1899, relating to the removal of obstructions from navigable waters of the United States, and the validity of proceedings taken, and orders made, thereunder in connection with plaintiff in error's bridge over the Mississippi River at Hannibal, Missouri, are stated in the opinion. Mr. R. Burnham Moffat, for plaintiff in error, Hannibal Bridge Company; Mr. Wells H. Blodgett, with whom Mr. James L. Minnis, and Mr. George A. Mahan were on the brief, for plaintiff in error, Wabash Railroad Company: The special act of July 25, 1866, under which the bridge was erected, and which reserved to Congress the power to require changes in the structure, was not repealed, or in any wise affected, by the subsequent general law of March 3, 1899, under which this proceeding was instituted. State v. Stoll, 17 Wall. 436; Rogers v. United States, 185 U. S. 87; Sedgwick on Stat. Const. 123; Bishop, Written Law, § 112-B; Commissioners v. Board of Public Works, 39 Oh. St. 628; Fosdic v. Perrysburg, 14 Oh. St. 472. The bridge having been erected in accordance with the act of 1866, it became a lawful structure, and necessarily continues so until that act shall be amended. What Congress has made lawful, only Congress can make unlawful. United States v. Keokuk Bridge Co., 45 Fed. Rep. 178. The alterations to be made in the bridge were not described, in the notice, with such certainty as to enable the defendants to know when they had complied therewith. As the only offense charged in the information consisted of a failure, on the part of defendants, to do the things required to be done by the notice, it follows that the things required to be done should have been described Argument for Plaintiff in Error. 221 U.S. in the notice with the same degree of certainty that is required in describing the things that may be done, or may not be done, in a penal statute. United States v. Keokuk Bridge Co., 45 Fed. Rep. 178; Chicago & N. W. Ry. Co. v. Dey, 35 Fed. Rep. 876; United States v. Cruikshank, 92 U. S. 557; McConville v. Myer, 39 N. J. Law, 38; Louisville & Nashville Ry. Co. v. Commissioners, 19 Fed. Rep. 679. A contract for work, of such vague description, could not be specifically enforced. If this were a suit on a contract to build a long pier, a proper guard fence, or a good house, there could be no decree for specific performance, because of insufficient description of the work to be performed. Bishop on Contracts, § 316; Beach on Contracts, § 76. Defendants should have been discharged, because it was no offense under § 18 of the act of 1899, to refuse to comply with the notice signed by the Assistant Secretary of War. That office is not mentioned in § 18, and criminal statutes cannot be enlarged by construction, nor can new, or additional words, be read into them. There is nothing in the act creating the office that advised defendants that they were required to obey a notice signed by that officer. 26 Stat. 17; United States v. Willberger, 5 Wheat. 76; United States v. Harris, 177 U. S. 305; In re Enterprise, 1 Paine, 32. The parties owning and operating the bridge were not given a reasonable opportunity to be heard, in the sense in which those words are employed in the act of 1899. The words "hearing" and "reasonable opportunity to be heard," are not new in legislative enactments. They signify the right to be present, to be represented by counsel, to have the witnesses testify under sanction of an oath, and the right of cross-examination. These rights were not accorded to defendants. Keach v. Thompson, 94 N. Y. 451; Mayor v. Nichols, 79 N. Y. 582. 221 U. S. Argument for the United States. There was a fatal variance between material allegations of the information, and the proof; the allegation being that the Secretary of War gave the notice, and the proof being that the Assistant Secretary of War gave the notice. United States v. Cantril, 4 Cranch, 167; United States v. Hardyman, 13 Pet. 176. There was absolutely no proof offered, either at the socalled "hearing" before the Secretary or at the trial of the defendants in the District Court, to support the charge in the information to the effect that the bridge was not erected in accordance with the act of July 25, 1866. Congress has not, by the act of 1866, surrendered its right to determine, for the purposes of the contract, the fact upon which alone it may require alterations; plaintiffs in error are entitled to an ascertainment of the fact by Congress, and not by an officer of one of the executive departments of the Government. United States v. Central Pacific R. R. Co., 118 U. S. 235; Walker v. Whitehead, 16 Wall. 314; People ex rel. v. Otis, 90 N. Y. 48; State v. Julow, 129 Missouri, 172. Mr. Assistant Attorney General Harr for the United States: The power conferred upon the Secretary of War by § 18 of the act of March 3, 1899, 30 Stat. 1121, 1153, may be exercised with respect to the Hannibal bridge, although constructed pursuant to the act of July 25, 1866, 14 Stat. 244. The rule generalia specialibus non derogant has no application. 25 Op. A. G. 212; United States v. Keokuk Bridge Co., 45 Fed. Rep. 178, upon which plaintiffs in error rely; Union Bridge Co. v. United States, 204 U. S. 364; Monongahela Bridge Co. v. United States, 216 U. S. 177, 194. Even if § 18 of the act of 1899, does not apply to a bridge constructed pursuant to the act of July 25, 1866, the action of the Secretary of War and the proceedings Argument for the United States. 221 U.S. in this case are none the less authorized and valid as the Hannibal bridge was constructed in accordance with the act of July 25, 1866. Hannibal Railroad Co. v. Packet Co., 125 U. S. 260, 269. The alterations specified in the notice served upon plaintiffs in error were set forth with sufficient particularity. The notice to alter, signed by the Assistant Secretary of War, met the requirements of § 18. On its face, and in legal effect, the notice is given by the Secretary of War, the Assistant Secretary, who signed it, being merely the medium for its transmittal. Miller v. Mayor, 109 U. S. 385; Wilcox v. Jackson, 13 Pet. 498; Wolsey v. Chapman, 101 U. S. 755, 769. In the absence of any proof to the contrary, it must be assumed that the statements contained in the notice were true and that the Assistant Secretary was authorized by the Secretary to send the same. United States v. Peralta, 19 How. 343, 347; Parish v. United States, 100 U. S. 500; United States v. Adams, 24 Fed. Rep. 348, 351; John Shillito Co. v. McClung, 51 Fed. Rep. 868; Re Huttman, 70 Fed. Rep. 699; Billings v. United States, 23 C. Cl. 166; Act of March 5, 1890, 26 Stat. 17; United States v. Heinszen, 206 U. S. 370, 382. The hearing accorded plaintiffs in error met the requirements of § 18. Having acquiesced not only in the manner of conducting the original hearing, but the rehearing as well, any objection by them at this time comes too late. Union Bridge Co. v. United States, 204 U. S. 364, 369; Monongahela Bridge Co. v. United States, 216 U. S. 177. Inquiry as to whether a bridge is a reasonable obstruction to navigation is a legislative and not a judicial one. Bridge Company v. United States, 105 U. S. 475. The proceeding is not the exercise of the power of eminent domain. Cooley's Const. Lim., § 564. The ac tion of Congress in requiring the alteration of bridges across navigable waterways to meet the needs of navigation is not the exercise of the power of eminent domain but of police power, to the exercise of which uncompensated obedience is required. Union Bridge Co. v. United States, 204 U. S. 364; Gibson v. United States, 166 U. S. 269; Scranton v. Wheeler, 179 U. S. 141; New Orleans Gas Light Co. v. Drainage Commissioners, 197 U. S. 453; C., B. & Q. R. R. Co. v. Drainage Commissioners, 200 U. S. 561; West Chicago Street Railroad v. Chicago, 201 U. S. 506. And see as to hearings, The Japanese Immigrant Case, 189 U. S. 86; Cooley's Const. Lim., § 496; Spencer v. Merchant, 125 U. S. 345; Hibben v. Smith, 191 U. S. 310; Cooley on Taxation, 3d ed., 59; King v. Mullins, 171 U. S. 429. The parties to this proceeding are not in a position to question the sufficiency of the hearing in this case, in the respects to which they refer, because they not only acquiesced but participated in the procedure followed without any objection whatsoever. MR. JUSTICE HARLAN delivered the opinion of the court. This is a criminal Information against the Hannibal Bridge Company, the Wabash Railroad Company, and the Missouri Pacific Railway Company, under the eighteenth section of the River and Harbor Appropriation Act of Congress of March 3, 1899, c. 425, 30 Stat. 1121. That section is as follows: "Whenever the Secretary of War shall have good reason to believe that any railroad or other bridge now constructed, or which may hereafter be constructed, over any of the navigable waterways of the United States is an unreasonable obstruction to the free navigation of such waters on account of insufficient height, width of span, or otherwise, or where there is difficulty in passing the draw opening or the draw span of such |