( c) Rise/fall of B with respect to A = 2435 165 ( Lower staff reading being higher) = 0785m, = with compare to A, the station point B being 0785m higher 13 Compare height of collimation method and rise and fall method a Height of collimation method bRise and fall methodFirst one is rise and fall method, and the height of instrument method is the other one The letters of HI means height of instrument, in other terms its called height of collimation BS FS = if the answer is above 0, is called rise At the answer is below zero is called fallAug 11, 08 · its done in table form & is basically BS FS to give a rise or a fall if its a rise add it to the reduced level If its a fall take it away (you should have been given a bench mark for a level for the starting point ie the reduced level starting point metres in this example) Ppt Booking Calculations Rise Fall Method Powerpoint Presentation Id 4142 Rise and fall method questions and answers