On a recent Wednesday morning, a dozen 8-by-10 black-and-white glossy photographs of Black history giants Muhammad Ali, Billie Holiday, and W.E.B. Du Bois were fanned out on a table in Temple University’s Charles L. Blockson Afro-American Collection. They are among the hundreds of images and 300,000 negatives captured by mid-20th century photographer John W. Mosley at the original Pyramid Club, a social network of Philadelphia’s prominent Black men who, from the late 1930s through the early 1960