D contracted to build a bridge. D bid out the concrete portion of 3,933 square yards. That sum was an estimate for the project. P got the subcontract and actually poured 8,100 square yards. When the work was finished, P's specification shows charges for work done aggregating $153,928.83, with credits of $106,116.74. P seeks to recover the balance of $47,812.09. P denied liability for any sum in excess of $820.09. D denied that P was due more than the payment for anything but the square yards of concrete for the upper deck, which was 4,184 square yards. The court found for D, in that the subcontract required D to pay for concrete placed on the upper deck. P excepted to a finding and ruling that the words 'concrete surface included in the bridge deck' are 'not so plain and clear that reasonable men could not differ as to their meaning,' upon the ground among others that 'read in their context and in the light of attendant circumstances [they] are not ambiguous.”