As a boy, Harrison Tyler (chemical engineering '51) never gave much thought to his grandfather, John Tyler, the 10th president of the United States. "I grew up during World War II," he told Subaru Drive Magazine in 2002, "and surviving the war and the shortages was what was on everybody's mind. Being related to a president was never a thought." Such a view may seem astonishing, but President Tyler died in 1862, 66 years before his grandson was born. In fact, Harrison Tyler's father, Lyon Gardiner Tyler, was born in 1853 and died in 1935, so there were very few...