Sakamoto Tenzan
Sakamoto Toshiyasu, better known as Sakamoto Tenzan, was a Japanese samurai, master of hōjutsu, and scholar of kokugaku. He established the Tenzan Ryū of gunnery.
Biography
Sakamoto Tenzan was born the eldest son of Sakamoto Unshirō Hideomi, a retainer of the Naitō clan and master of the Ogino school of gunnery.In 1767, when he was 22 years old, Sakamoto traveled to Osaka to study under the instruction of Ogino Rokubee Terukiyo.
In 1778, Sakamoto published an advanced design for a portable swivel gun called a shūhatsudai. He explained the gun using concepts from the Yijing.
In his later years, Sakamoto investigated measures for erosion and flood control. Earning the ire of his colleagues, he was ordered into house arrest for several years before being released. He died in 1803.