After finishing high school in 1883, Zeeman went to Delft. He studied classical languages, which he needed for admission to University. He stayed with Dr J. W. Lely, co-principal of the gymnasium. Lely was the brother of Cornelis Lely, who was responsible for the idea and building of the Zuiderzee Works. In Delft, he met Heike Kamerlingh Onnes, who was to become his thesis adviser.