21 ELECTRIC HAND MANIPULATED SURFACE TREATING AND FINISHING MACHINES AND TOOLS-NAMELY, MACHINES AND PARTS THEREFOR FOR PRODUCING AND MAINTAINING A FINISH ON FLOORS OF ALL KINDS INCLUDING WOOD, TERRAZZO, MARBLE, LINOLEUM, TILE, CEMENT, COMPOSITION, OR METAL; MACHINES AND PARTS THEREFOR FOR SANDING, CLEANING, SCOURING, SCRUBBING, RUBBING, SHAPING, DRESSING, WAXING, POLISHING, AND BURNISHING SURFACES SUCH AS FLOORS OF THE FOREGOING CHARACTER, TERRAZZO BASE WORK, WAINSCOTING, WALLS, STAIRWAY TREADS, CARPETS AND RUGS; SANDER PLANES FOR REMOVING STENCIL MARKS ON SHIPPING BOXES, BARRELS, AND FOR REFINISHING DESK AND TABLE TOPS; PORTABLE HAND-MANIPULATED ELECTRIC SANDING DEVICES, PLANES AND MACHINES; ALSO FOR PORTABLE ROTARY POWER HAND SAWS