Final answer:
Callimachus was the first chief librarian and overseer of the Museion, also known as the Library of Alexandria, which is considered the first research university in the western world.
Step-by-step explanation:
Callimachus was the first chief librarian and overseer of the Museion, also known as the Library of Alexandria. As an intellectual hub of the Hellenistic world, the Library of Alexandria and its associated Museon often considered to be the first research university in the western world. This significant institution, directly funded by the Ptolemaic government, was not just a repository of 700,000 scrolls, but also a center of scientific research and translation of scholarly works from across the Hellenistic world, housing lecture halls and laboratories. Among its many scholars was Eratosthenes, who succeeded Callimachus and became famous for calculating the Earth's circumference with remarkable accuracy.