Why G sounds lower than F harmonica

In many books I have read specify that G harmonica is the lowest sound and F key harmonica has the highest .Why is it ? If in the music staff is only one note appart Besides F is before G .So F should have lowest sound than G . I have played both harps and is true . But why?

I believe this is a question for JP and his Staff!
Good question! I know below G is called Low F and there are keys lower available!
Yes??? Why does it start with G?

Oh yeah .You just gave me a clue. Maybe it’s low G and hi F