Section 7(2)(c) in The Assam Agricultural Income-Tax Rules, 1939
(c)in the ease of assets acquired before the commencement of the Assam Agricultural Income-tax Act, the actual cost to the assessee less for each financial year since the acquisition, the amount of depreciation applicable to the assets at the rate prescribed for the purposes of the Indian Income-tax Act for each such year since the 1st April, 1922 at the Income-tax rates in force on the 1st April, 1922 for each year prior to the date :