4Rating of plant and machinery
(1)For the purpose of exempting from, or including in, any assessment or rate a class or classes of machinery, machines or plant, the Secretary of State may, in the definition of " lands and heritages " in section 42 of the [1854 c. 91.] Lands Valuation (Scotland) Act 1854, amend by order that proviso which relates to the construction of the expression " machinery fixed or attached"; and without prejudice to the generality of the foregoing provisions of this subsection, such amendment may be as regards—
(a)any plant fixed or attached to the lands and heritages; and
(b)any building which is an integral part of such plant.
(2)An order under subsection (1) above shall have no effect until approved by resolution of each House of Parliament.