J.C.SHAH, J.

(1) THE assessees are a firm carrying on business at Kurnool, of manufacturing ground-nut oil and cake. Under the Madras General Sales Tax Act IX of 1939, the assessees were entitled to a rebate of sales tax paid on goods purchased by them and used in the manufacturing process. The assessees maintained their books of account according to the Samvat Year ending with Diwali. The system of accounting was a mixture of mercantile and cash. Purchases and sales of goods on credit were duly entered in the books of account. The sales tax actually recovered by the tax authorities was debited when paid and amounts if any refunded were credited when received. The assessees had adopted the system which was permitted by the Act of paying tax calculated on the turnover of the previous year of account. Under this system, tax was provisionally assessed by the Sales Tax Officer on the basis of the turnover of the previous year, and thereafter the liability was adjusted at the end of the year of account in the light of the actual turnover of that year, and of rebate allowed in respect of groundnuts pressed into oil. As a result of the final adjustment made by the sa