COMMISSIONER OF INCOME-TAX, MADRAS vs MIR MOHD. ALI, BUS OWNER, VELLORE

The Supreme Court held that the assessee was entitled to extra depreciation under Sections 10(2)(vi) and 10(2)(via) of the Indian Income-tax Act, 1922, for replacing petrol engines with diesel engines in his buses. The Court applied the Privy Council's definition of 'machinery' from Corporation of Calcutta v. Chairman, Cossipore and Chitpore Municipality, affirming that a diesel engine qualifies as machinery and its installation in a vehicle meets the statutory requirements. The dissenting opinion argued that the replacement did not constitute installation of machinery as it was merely a part without independent use in the business.