It seems impossible to determine what is meant by the “mouth” of the laver, or what by its “chapiter.”
Related Commentaries of 1 Kings 7:31
1 Kings 7:31
31 And the mouth of it within the chapiter and above was a cubit: but the mouth thereof was round after the work of the base, a cubit and an half: and also upon the mouth of it were gravings with their borders, foursquare, not round.