It shall not be lawful for the company to proceed in the execution of the railway, unless they shall have previously to the commencement of such work deposited in the office of the principal sheriff clerk in every county in or through which the railway is intended to pass a plan and section of all such alterations from the original plan and section as shall have been approved of by Parliament, on the same scale and containing the same particulars as the original plan and section of the railway, and shall also have deposited with the schoolmasters of the several parishes, (or in royal burghs with the town clerk,) in or through which such alterations shall have been authorized to be made, copies or extracts of or from such plans and sections as shall relate to such parishes respectively.