### Instruction: From the passage provided, extract when Susanna started as a principal.
### Input: Susanna Gossweiler (1740–1793), was a Swiss educator. She was appointed the first principal of the girls' school Töchterschule in Zürich in 1774, and regarded a pioneer of women's education in Switzerland.
### Response: Susanna started as a principal of Töchterschule in 1774.