Who is this famous person?

Who is this famous person?

It is part of a larger picture taken in 1863. Seen here: The person in the center has just finished high school in 1863 and is seen with friends. He will later become a leading scientist.

It might surprise, but it is Ludwig Boltzmann. Just saw that in a nice book
“Boltzmann’s Legacy” by Giovanni Gallavotti Wolfgang L. Reiter Jakob Yngvason, Editors,
European mathematical society.

The capture of the picture is

Ludwig Boltzmann (center) with fellow students after the Matura in Linz 1863 (Courtesy of Ilse M. Fasol-Boltzmann and Gerhard Ludwig Fasol)

The book contains an other picture: