farmer for his crops, a mechanic, artisan, or laborer for his work, a lawyer or doctor for his professional services. But railroad companies cannot do this. They may be regulated in the matter of their charges by the public, acting through its proper agents. All these facts, and others which it is not necessary to enumerate, place railroads in a different class by themselves, differing from every other person and individual, and make them legitimate objects of special legislation; as, for instance, the imposing upon them, as employers, of a different rule of liability to any employe for injury received by the negligence of a fellow servant from that governing employers generally (Railroad Co. v. Mackey, 127 U. 8. 205, 8 Sup. Ct. Rep. 1161;) subjecting them to a special law to determine, for purposes of taxation, the value of their property (Kentucky Railroad Tax Cases, 115 U. 8. 321, 6 Sup. Ct. Rep. 57;) the regulation of the charges which they may make for their services (Munn v. Illinois, 94 U. S. 113; the Granger Cases, Id 155; Stone v. Trust Co., 116 U. S. 307, 6 Sup. Ct. Rep. 334, 388, 1191;) requiring them to fence their railroad tracks, and, in case of failure 80 to do, to be liable to any person aggrieved in double damages (Railroad Co. v. Humes, 115 U. 8. 513, 6 Sup. Ct Rep. 110;) and compelling one railroad company operating a certain number of miles of railroad to charge one maximum rate for the carriage of passengers, and another company operating another number of miles of railroad to charge another maximum rate (Dow v. Beidelman, 125 U. S. 680, 8 Sup. Ct. Rep. 1028.) We are therefore clearly of opinion that railroad companies may be classified by themselves for the purposes of legislation, and it follows that, as taxation is a legitimate subject of legislation, they may be classified for purposes of taxation. We do not understand that respondent denies this proposition in so far as railroad property actually used in the operation of railroads is concerned. It is, however, earnestly argued that the appellant, in respect of its land grant, is in precisely the same position as any other owner of land, and that to exempt this land grant is, in effect, to cast additional burdens upon such other property owner, and to deny to him the equal protection of the law. The exemption of appellant's land grant
