দিয়ারা আঞ্চলিক সেটেলমেন্ট অফিস, বরিশাল Ramsden's theodolite represented a great action forward inside the instrument's accuracy. William Gascoigne invented an instrument that utilised a telescope with an put in crosshair to be a goal product, in 1640. James Watt developed an optical meter to the measuring of length in https://judahmkznb.bloggosite.com/36013840/fascination-about-topographic-land-survey-bangladesh