5 - A differential leveling circuit began at BM Rock ( elv . 543. 202 ) and closed at BM Manhole ( elv . 542.551 ) . The BS and FS distances were kept approximately equal . Readings listed in the order taken are : BM Rock ( BS = 1.59.9 ), TP1 ( FS = 0. 987, BS = 1. 105 ), BMIZ ( FS = 0. 842, BS = 0. 679 ). BMB ( FS = 1. 846, BS = 0. 849 ), TPZ ( FS = 1. 895, BS = 1. 436 ), and BM Manhole* ( FS = 0. 704 ). Prepare , check , and adjust the notes . Point BS FS Elevation BM Rock 1.59.9 543. 202 TP 1 1. 105 0. 987 BMIZ 0. 679 0. 842 BM3 0. 849 1.846 TP Z 1.436 1. 895 BM Manhole* 0. 704 542.551