鹿児島湾
Meanwhile, Japan endeavoured to learn about foreign sciences through rangaku ("Western studies"). To reinforce Japan's capability to carry on the orders to repel Westerners, some such as the Nagasaki-based Takashima Shūhan managed to obtain weapons through the Dutch at Dejima, such as field guns, mortars and firearms. Domains sent students to learn from Takashima in Nagasaki, from Satsuma Domain after the intrusion of an American warship in 1837 in Kagoshima Bay, and from Saga Domain and Chōshū Domain, all southern domains mostly exposed to Western intrusions. These domains also studied the manufacture of Western weapons. By 1852 Satsuma and Saga had reverberatory furnaces to produce the iron necessary for firearms.