Arrange the following description in the form of profile level notes complete to elevation. A level is set up and a reading of 3.120m is taken on a benchmark, the elevation of which is 35.780m. At the beginning of the line to be profiled the rod reading is 2.789m, 30m from the beginning, it is 1.535m, at 60m it is 0.890m, at 66m and 81m, the rod readings are 1.462m and 0.678m, respectively. On a rock that is not on the line, the rod reading is 0.777m. The level is then removed ahead, set up and a rod reading of 2.110m is observed, the rod still being held on the rock. The readings along the profile are the assumed 90m from the beginning of the line, the rod reading is 1.159m, 120m from the beginning of the line, rod reading is 1.545m, finally 150m from the beginning of the line the rod reading is 2.345m. Compute the difference in elevation at a point 150m and 81m from the beginning of the line.