21.   This is needed for electron microprobe or back-scattered Scanning Electron Microscope work where a perfect surface is required.

22.   Thousands of years ago the surface was barren desert.

23.   Use a heavy-duty solvent-based type instead if the roof surface is in very poor condition.

24.   When using glue, make sure both surfaces are completely clean.

25.   Why should there be a surface to get beneath, a skin to get under?

26.   The surface of wood was rough.

27.   The surface is cool to the touch.

28.   The surface initially will be whindust but eventually there is the possibility of asphalt.

29.   The radiating ribs are crossed by lierne ribs and the whole surface is then, like the windows, walls and buttresses, panelled and cusped.