The mayor and aldermen of cities and selectmen of towns cannot lawfully lay out and establish a town way across a railroad, without first obtaining authority therefor from the county commissioners. Gen. Sts. c. 63, § 59. The word “ railroad,” as used in this section, is to be interpreted as meaning all the land, not exceeding five rods in width, taken by a railroad corporation for their road, which is included within the location thereof, filed according to law with the commissioners of the county within which the land is situate. The track or iron rails on which cars and carriages are to pass and travel may be laid down on any part of the surface of the land within the limits of the location, and they may be changed and shifted from place to place thereon, as may be required for the convenience or reasonable accommodation of the company, which may also erect on the land such structures and buildings as are reasonably incident to the support of the road. Worcester v. Western Railroad, 4 Met. 564. These are very important rights and privileges, and it is obvious that the legislature did not intend that they should be interfered with or in effect taken away from the corporation, by the laying out of a town way, unless the public convenience and necessity therefor should appear to the county commissioners to be so plain and manifest as to induce them to authorize the municipal authorities to make the location.

No such authority was given by the commissioners of the county of Essex to the selectmen of the town of Haverhill to lay out the way called Washington Avenue over the railroad. If, therefore, the description of the town way, as laid out by the selectmen, does cover or include any part of the land within the limits of the location of the railroad, to that extent the laying *525out of the town way was unauthorized, and is void. The instructions to the jury should have been to that effect. Having been otherwise, they were erroneous, and the defendants’ exceptions thereto must be sustained.