Show how sand dunce travel trav in the desert of la joys joya peru here heie are dikou thousands of cressent shaped cand dunes formed by the winds and slowly advancing across the level surface one investigator measured one of these lioe lio e dunes the points 0 of f whose ca 4 ent ere feet apart while the auba the convex side bide was ati fa width at the widest part of 01 t re scent was more than feet J weight glit of the sand composing the 1 trine ans its estimated at tons yet it moved 12 feet in a year all AH the dunes have the same form unil and nil 1111 have the convex side toward the hie pio ahl south i winds wind |