In Mir Mohamlnad's case on which the High Court based .its decisions, the assessee,. ·a bus-owner and transport operator, replaced the petrol B engines in two of his buses incurring expenditure in that connection during the year of account ending with March 31, 1950, relevant to the assessment year 1950-51. This Court bv a majority held .that the same meaning ought to be given to the word "machinery" in all the clauses, namely, clauses (iv), ( v), (vi) and (vi-a) of sec. 10 (2) of the Income-Tax Act, 1922 as then in force, that a diesel engine was clearly machinery, and that when an engine was fixed in a vehicle it c was installed within the meaning of the expression in clauses (vi) and (vi-a) of sec. 10( 2) as it then stood. This Court accordingly held that the assessee was entitled to tl).e extra depreciation allowances under the second paragraph of clause (vi) and clause (vi-a) of sec. 10( 2) as in force at the relevant time.