Said lands shall be entered upon said book in convenient subdivisions, as surveyed by United States deputy surveyors, with appropriate columns, showing the names of resident owners, and nonresident owners when known, of said lands, and of any person or persons holding recorded liens or encumbrances, if known to the assessor; also, the number of acres cleared and uncleared, as nearly as said assessor can ascertain the same without actual measurement, the value thereof as assessed by him, without the work, and the value thereof as improved by the work; provided, that no error in the description of any of said lands shall invalidate such assessment, if sufficient description is given to ascertain where the lands are situated.