All companies or associations of persons incorporated or organized for the purpose of constructing telegraph or telephone lines shall be authorized to construct the same, and to set up and erect their posts and fixtures along and across any of the public highways, streets, or waters, and along and across all turnpikes, railroads, and canals, and also through any of the public lands. Such lines, posts and fixtures shall be so constructed and placed as not to be dangerous to persons or property, and as not to interfere with the common use of such roads, streets, or waters, or with the convenience of any landowner more than may be unavoidable. In case it shall be necessary to cross any highway, such lines, posts and fixtures shall be so constructed as to cross such highway at right angles.