The statute provides that railroads laid out so as to cross a turnpike road or other way shall be so made as not to obstruct it. Rev. Sts. c. 39, § 66. But when a railroad corporation has duly and legally located its road upon and across a public highway, and has acquired a right to construct and complete it there at a certain fixed grade and level, without any restriction as to the number of tracks or the place where they shall be laid, the company is authorized to put down and maintain upon any part of the premises within the limits of the location, such number of tracks as are essential to the convenient transaction of its business; and for that purpose may make any necessary alteration in the grade or surface of the *381highway there. And such alteration will not constitute a nuisance or an unlawful obstruction, if in all other respects the highway is kept in good repair, so as to be safe and convenient to passengers. The defendants therefore were entitled, upon the facts shown at the trial, to the instructions prayed for

Exceptions sustained