What's the difference between i.e. and e.g.?
the use of undressed, rough stone, generally in the construction of walls. Dry-stone random rubble walls, for which rough stones are piled up without mortar, are the most basic form. An intermediate method is coursed rubble walling, for which stones are roughly dressed and laid in courses. Snecked rubble features stones of varying sizes with small fillers or snecks between them.