CBS' 60 Minutes, celebrating its 40th year on the air, has seen its signature clock logo evolve over the years. Image 1 of 4 81086-18906_200x155.jpg Image 2 of 4 78811-18907_200x255.jpg Image 3 of 4 80549-18908_200x279.jpg Image 4 of 4 79121-18909_200x247.jpg
