What’s the price of gold for 1880-1940 according to the U.S. price or London price?
What’s the exchange rate between U.S. & U.K. or U.S. & China at this time?
Interest rates – short term or long term
GDP per capita
Answer was found at:
http://www.measuringworth.com/datasets/gold/result.php
http://www.measuringworth.com/aboutus.html
