Judgment

GROVER, J.: This judgment will dispose of two sets of cross appeals Nos. 1153-1160 and 1161-1168/68 which are from a common judgment of the Madhya Pradesh High Court and have been entertained by special leave.

2. The relevant assessment years for the purpose of levy of sales tax are from April 1, 1957 to March 31, 1958 and April 1, 1964 to March 31, 1965. For the assessment years prior to April 1, 1959 the enactment in force was the C. P. and Berar Sales Tax Act, 1947 (No. XXI of 194) and for the subsequent two years it is the Madhya Pradesh General Sales Tax Act (Act. No. 2 of 1959), which would be applicable. The material facts may be shortly stated. The assessee- Madhya Pradesh Electricity Board-hereinafter called the "Electricity Board" is a body constituted under Section 5 of the electricity Supply Act 1948. Under Sec. 18 of that Act it was the general duty of the Electricity Board to promote co-ordinated development of the generation, supply and distribution of electric energy within the State of Madhya Pradesh in the most efficient and economical manner. In the assessment years in question the Electricity Board sold, supplied and distributed electric energy to various