Tenpō Tsūhō (Honza chōkaku)

First cast in the sixth year of Tenpō. An oval that recalls the koban, with a square hole cut through it, and cast on the back 'tō hyaku', worth one hundred, with the cipher of the Gotō house of the gold mint. About 50 millimetres long, weight 5 monme 5 bu, about 20.6 grams. The metal in it is only that of five or six one-mon pieces, and in the town it passed at 80 mon. It is the coin with which the shogunate itself tried out, in the crudest form of all, the argument that writing a hundred makes it a hundred.