<div class="htmlview paragraph">Direct and indirect evidence for the nature of lunar surface materials are examined and compared with theoretical predictions. Conclusions are then drawn concerning the most probable character of these materials. It is concluded that the lunar surface is covered with a layer of rubble of highly variable thickness and block size. The rubble in turn is mantled with a thin layer of highly porous dust with a complex surface and no significant coherence. Surface roughness at a meter scale remains in doubt.</div>