Srinivasan, J.

Defendants 1 to 4 have preferred this appeal against the judgment and decree in O.S. No.228 of 1981 on the file of the Subordinate Judge’s Court, Periyakulam. The parties will be referred to hereinafter in accordance with their rank in the suit.

2. The first plaintiff is a partnership firm carrying on business in engineering jobs and construction works. The second plaintiff is the managing partner thereof. The plaintiffs entered into an agreement with the first defendant on 2. 1974 for the execution of Suruliyar Hydro Electric Project Highways Dam excavation for foundation from Chainage 55 Metres to end of Dam, i.e., Chainage 165 metres upto the top of Highways Dam in Suruliyar Upper Cam -Specification No. SMH.37 Tender dated 18. 1973. The plaintiffs took over the site on 2. 1974 and started excavation work. The agreement was engrossed on stamp paper and signed by the parties on 111. 1974, which is marked as Ex.B-1. The plaintiffs commenced the masonry work on 7. 1976. Since then the excavation as well as masonry work were simultaneously carried out. According to the plaintiffs the work was completed by the end of the year 1978 and the last payment made b