A RESEARCH GRANT commits a city's workshops to the pursuit of knowledge instead of goods.
The city never finishes it. Each turn its production is converted directly into research for the whole empire.
Set it, and leave it set.
Requires WRITING.
For a city with every improvement already raised — or a people who have fallen behind and have nothing worth the building — the foundry is better spent on the library.
Nations that cannot out-produce their rivals may still out-think them.