Incidentally and on an vaguely related note, Pytheas (that I mentioned here: https://news.ycombinator.com/item?id=18801645 https://news.ycombinator.com/item?id=

Incidentally and on an vaguely related note, Pytheas (that I mentioned here: https://news.ycombinator.com/item?id=18801645 https://news.ycombinator.com/item?id=18801645 ) also was the first recorded to measure latitude using a gnomon.