It's missing so much, like the know used to be defined at 42 fathoms per 30 seconds, giving 5040 ft per hour, which was close to the original definition of the mile. Then when the nautical mile was more useful it became 47'3" in 28 seconds, which equates to 6075 ft/hr, which is pretty close to the idea of 1 NM/hr.

There's more, but it's pretty good. A fun read.

Challenge question, a snail's pace is a furlong/fortnight. How fast is that in SI units?