William Rutherford

William Rutherford (1798–1871) was an English mathematician famous for his calculation of 208 digits of the mathematical constant π in 1841. Only the first 152 calculated digits were later found to be correct; but that broke the record of the time, which was held by the Slovenian mathematician Jurij Vega since 1789 (126 first digits correct) For the current record, see Chronology of computation of π. Rutherford used the following formula: π 4 = 4 arctan ⁡ ( 1 5 ) − arctan ⁡ ( 1 70 ) + arctan ⁡ ( 1 99 ) {\displaystyle {\pi \over 4}=4\arctan \left({1 \over 5}\right)-\arctan \left({1 \over 70}\right)+\arctan \left({1 \over 99}\right)}