(c)fix the minimum rate [per kilometre] [Substituted by Act 35 of 1977, Section 25, for "per mile" (w.e.f. 1.5.178).] which may be charged for freight on goods of any description carried in inland [Mechanically Propelled Vessels] [Substituted by Act 35 of 1977, Section 5, for "steam-veseel" (w.e.f. 1.5.1978).]; and