> Imagine taking a time machine back to 1750—a time when ... all transportation ran on hay wait, what? weren't ocean-going ships using wind power in 1750? come

> Imagine taking a time machine back to 1750—a time when ... all transportation ran on hay wait, what? weren't ocean-going ships using wind power in 1750? come to think of it, weren't ships using wind power in 1750 BC?