ɪt wʌz nˌɑːt ʌntˈɪl wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd nˈaɪnti wˈʌn ðætðɪ ɐmˈɛɹɪkən ɐstɹˈɑːnəmɚ, sˈɛθ kˈɑːɹloʊ tʃˈændlɚ, mˌeɪd mˈɛʒɚmənts ʃˈoʊɪŋ ðæt ðɛɹwˌʌz ɐ pˌiəɹɪˈɑːdɪk mˈoʊʃən ʌv fˈoːɹtiːn mˈʌnθs ɪnðɪ ˈɜːθz wˈɑːbəl ænd sədʒˈɛstɪŋ ðæt ðɪs wʌzðə pˈɑːlhoʊd mˈoʊʃən.
It was not until 1891 that the American astronomer, Seth Carlo Chandler, made measurements showing that there was a periodic motion of 14 months in the Earth’s wobble and suggesting that this was the polhode motion.