World Coin BookWorld coin encyclopedia

Cross-country learning guide

Time-Bounded Currency Conversion

Documented official, treaty, bullion, and market relationships; explicitly not a universal historical converter.

Date requiredLocation requiredRate typeUncertainty
Routes
14
Relationships
8
Ports
8
Status
Published

Not a universal converter

Every relationship requires date, place, type, and source

Official, treaty, market, and bullion relationships are not interchangeable. Missing numeric market values remain narrative rather than invented numbers.

Time-bounded conversion records
DateLocationFromToTypeRecorded rateLimit
1854–1858Shimoda and early treaty negotiationsMexican silver dollarIchibu-ginofficial1 dollar = 1 Ichibu-ginDo not project beyond this date and location.
1859–1860Opened Japanese treaty portsMexican silver dollarIchibu-gintreaty1 dollar = 3 Ichibu-ginA bounded treaty convention, not a general Asia-wide rate.
late 1850sJapangold bullion valuesilver bullion valuebullionapproximately 1:4.6 to 1:5Historical approximation used to explain incentives, not a posted retail quote.
1878ShanghaiMexican dollarShanghai tael / syceemarketdaily market value; documentary report notes premiums and variationNo single numeric rate is normalized because the cited record documents volatility.
1946TaiwanTaiwanese yenOld Taiwan dollarofficial1:1Postwar administrative conversion; banknote context only.
1949TaiwanOld Taiwan dollarNew Taiwan dollarofficial40,000:1Postwar currency reform; banknote context only.

Source trail

Institutional and contemporary evidence