দিয়ারা আঞ্চলিক সেটেলমেন্ট অফিস, বরিশাল Ramsden's theodolite represented an excellent phase forward from the instrument's precision. William Gascoigne invented an instrument that used a telescope with the installed crosshair to be a target machine, in 1640. James Watt developed an optical meter to the measuring of length in 1771; https://charlesk308bks5.life3dblog.com/profile