RECIPROCAL LEVELING. In reciprocal leveling across a deep ravine the following sets of rod readings were takent: Instr Near A: BS on A=1.719 m, Average Fs on B=2.578 m Instr Near B: Average BS on A=1.335 m, FS n B=2.176 m Point A is on one side of the ravine and has a known éle- vation of 197.428 m. Point B is on the other side. Deter- mine the elevation of point B.