Trip to California. Diary of the mathematician Oskar Bolza

In April 1913, a small party set off to America from Freiburg. A short stop in Rotterdam allowed for enough time to buy tickets for the passage, and a photograph was taken: It shows the group crowded into a mock-up of an airplane – a little joke and an idle wish considering the nine-day sea journey that lay ahead of them. The photograph is in an album created by the mathematician Oskar Bolza, which also includes diary entries, postcards and similar items. With it he sought to commemorate his trip from New York to Washington and on to the Yosemite Valley in California.