3U 
Bul. 300, U. S. Dept. of Agriculture. PEATE IY. 
D-3281 
FiG. 1.—DRAG-LINE EXCAVATOR ON SKID-AND-ROLLER MOUNTING 
TRANSFERRING A SECTION OF TRACK AHEAD. 
Fic. 2.—DRAG-LINE EXCAVATOR MOUNTED ON TWO CATERPILLARS. 
