23 SELF-PROPELLED AND POWERED EARTH AND MATERIAL HANDLING AND WORKING MACHINES-NAMELY, SHOVELS, LOADERS, BACKHOES, TRENCH DIGGERS, BULLDOZERS, EARTH BACK-FILLERS, AND EARTH BORERS; CABLE LAYING MACHINES AND CABLE PLOWS; TRACTOR ATTACHMENTS-NAMELY, EARTH-WORKING ATTACHMENTS, MATERIAL HANDLING ATTACHMENTS, ADN GROUND-ENGAGING ATTACHMENTS; AND PARTS FOR ALL OF THE AFORESAID GOODS