Do you know how many scientists or mathematicians were born in Ojiya? “HIROKAWA SEIKEN” is one of them. He was born as the second son of a wealthy merchant in Ojiya in 1803. He became a disciple of “SATOU SETSUZAN” and studied Japanese mathematics and went to “EDO” to learn Western learning.

He wrote many books. “SANGENSO RYAKUSETSU” is one of his books. “SANGENSO” means three elements of heat, light and electricity. He insisted these three elements were intrinsically equal against Western idea, in which the three elements were considered as different kinds of elements. Unfortunately, his book had been neglected until “KANOU KOUKICHI” praised him for his work and original mind in the middle of Meiji period. He also proposed the solar calendar to parliament of those days but it was not adopted.

He tried to earn his living by managing his private schools in Edo and in Ojiya. Disappointedly, few students joined and he failed. He spent the rest of his life quietly at the head family. It also seems that his name is far from Ojiyan people’s memory and forgotten faintly.

“HIROKAWA SEIKEN” succeeded to “TOKUSABUROU” and now sleeping on a hill where you can see “SINANO GAWA”. I would like to thank a priest of “CHORAKUJI” for kindly telling me a place of his grave and fascinating related stories. His materials and surveying apparatus, which are designated as cultural properties by Niigata pref., are preserved by the educational committee of Ojiya.

参考：小千谷市ホームページ

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