02 July 1971
Vol 173, Issue 3991

About The Cover

Holographic interferogram revealing dangerous bonding defect located deep inside an automabile tire. By combining lasers and holography, the nondestructive method of ``holographic interferometry'' has introduced a new form of interferometry into optics, capable of revealing microscopic deformations on large-size objects. see page 11 [GC-OPTRONICS, Ann Arbor,Michigan]