nˈuːkoʊm ɹˈiːəlaɪzd ðætðɪ ˈɜːθz mˈæs ɪz pˈɑːɹtli ɹˈɪdʒɪd ænd pˈɑːɹtli ᵻlˈæstɪk, ænd ðætðɪ ᵻlˈæstɪk kəmpˈoʊnənt hɐz nˈoʊ ɪfˈɛkt ɔnðɪ ˈɜːθz pˈɑːlhoʊd pˈiəɹɪəd, bɪkˈʌz ðɪ ᵻlˈæstɪk pˈɑːɹt ʌvðɪ ˈɜːθz mˈæs stɹˈɛtʃᵻz sˌoʊ ðˌɐɾɪt ɪz ˈɔːlweɪz sɪmˈɛtɹɪkəl ɐbˌaʊt ðɪ ˈɜːθz spˈɪn ˈæksɪs.
Newcomb realized that the Earth’s mass is partly rigid and partly elastic, and that the elastic component has no effect on the Earth’s polhode period, because the elastic part of the Earth’s mass stretches so that it is always symmetrical about the Earth’s spin axis.