( 1 ) THESE two references relate to the assessment year 1981-82 for which the relevant accounting year ended on March 31, 1981. The assessee, a registered firm, purchased machinery worth Rs. 16,23,348 for use and claimed investment allowance of Rs. 4,05,812 under Section 32a of the Income-tax Act, 1961. The assessee-firm was engaged in removing overburdens and raising of coal in Rajpura Colliery under the Eastern Coalfields Ltd. It was claimed that the work undertaken by the assessee-firm was a process which was normally carried on by a coal miner engaged in open cast mining and further claimed to be treated as an industrial undertaking eligible for investment allowance under Section 32a of the Act. The assessee also filed a letter of intent dated December 27, 1980, and a certificate dated February 22, 1984, from the agent of Rajpura Colliery. The Income-tax Officer found that the letter of intent indicated that the assessee would be paid at certain rate as hiring charges of heavy earth moving machinery. It was pointed out that from the tax deduction certificate issued by the collieries it was noticed that the payments were made against the contract for hirin