In the Netherlands Indies he worked for a short term as physician at Cirebon, Java, after which he was appointed to Dejima, the Dutch trading post in Japan. He arrived there on 1 August 1853. Since the beginning of the seventeenth century, the ruling Tokugawa shogunate of Japan pursued a policy of isolating the country from outside influences. Foreign trade was maintained only with the Dutch and the Chinese and was conducted exclusively at Nagasaki. However, by the early nineteenth century, this policy of isolation was increasingly under challenge. Following the Perry Expedition and with the increased threat to Japanese sovereignty posed by the European powers and their Black ships, the Japanese government turned towards the Dutch for technical and military assistance. The Nagasaki Naval Training Center was opened in 1855 with Dutch military advisors to teach the Japanese about steam warship technology.