1. To block up; to interpose obstacles; to render impassable; to fill with barriers or impediments; as to obstruct a road or way. U. S. v. Williams, 23 Fed. Cas. 033; Chase v. Oshkosh, 81 Wis. 313, 51 N. W. 5G0, 15 L. R. A. 553, 29 Am. St. Rep. S98; Overhouser v. American Cereal Co., 118 Iowa, 417, 92 N. W. 74; Gor- ham v. Withey, 52 Mich. 50, 17 N. W. 272. 2. To impede or hinder; to interpose obstacles or impediments, to the hindrance or frustration of some act or service; as to obstruct an officer in the execution of his duty. Davis v. State, 70 Ga. 722. 3. As applied to navigable waters, to “obstruct” them is to interpose such impedi- ments in the way of free and open navigation that vessels are thereby prevented from going where ordinarily they have a right to go or where they may find it necessary to go in their maneuvers. See In re City of Richmond (D. C.) 43 Fed. 88; Terre Haute Drawbridge Co. v. Halliday, 4 Ind. 30; The Vancouver, 28 Fed. Cas. 960. As applied to the operation of railroads, an “obstruction” may be either that which obstructs or hinders the free and safe passage of a train, or that which may re- ceive an injury or damage, such as it would be unlawful to inflict, if run over or against by the train, as in the case of cattle or a man approaching on the track. Nashville & C. R. Co. v. Carroll, 6 Heisk. (Tenn.) 368; Louisville N. & G. R. Co. v. Reidmond, 11 Lea (Tenn.) 205; South & North Alabama R. Co. v. Williams, 65 Ala. 77.