The yearly Rent or Value, in Terms of this Act, of the Lands and Heritages in any Parish, County, or Burgh belonging to or leased by any Railway or Canal Company, and forming Part of the Undertaking of such Company, shall be ascertained as follows; that is to say, there shall be deducted, in the first place, from the cumulo yearly Rent or Value of the whole Lands and Heritages in Scotland as aforesaid of each such Railway or Canal Company, a Sum equal to Three Pounds per Centum of the whole Cost as aforesaid of the Stations, Wharfs, Docks, Depots, Counting-houses, and other Houses and Places of Business in Scotland of and connected with the Undertaking of such Railway or Canal Company (including as aforesaid); and the Proportion of such diminished cumulo Rent or Value corresponding to the lineal Measurement of the Portion of the Line, including Ferries attached thereto, of such Railway or Canal Company, situated in such Parish, County, or Burgh, as compared with the lineal Measurement of the entire Line, including Ferries as aforesaid, of such Railway or Canal Company, with the Addition of a Sum equal to Three Pounds per Centum of the Cost as aforesaid of any Station, Wharf, Dock, Dep6t, Counting-house, or other House or Place of Business, within such Parish, County, or Burgh, or of or connected with the Undertaking of such Railway or Canal Company (including as aforesaid), shall be deemed and taken to be the yearly Rent or Value, in Terms of this Act, of the Lands and Heritages in such Parish, County, or Burgh belonging to or leased by such Railway or Canal Company, and forming Part of its Undertaking.