Two zigzag lines in phase : a beautiful street, (Lombard Street, San Francisco, California)
Two zigzag lines out of phase : a beautiful pier ( 14th Street pier, Myrtle Beach, South Carolina
Two zigzag lines in phase : a beautiful street, (Lombard Street, San Francisco, California)
Two zigzag lines out of phase : a beautiful pier ( 14th Street pier, Myrtle Beach, South Carolina