ðeɪ fˈɔːɹm ɐ pˈɑːɹt əvən ˈɑːɹtʃ ɪnðə mˈɪdəl, tə ɹᵻsˈiːv ɐ θˈɜːd pˈɑːɹt ʌvðə θˈɪknəs ʌvðə tɹˈʌniənz; fɔːɹ tˈuː θˈɜːdz ʌv ðˌɛm ɑːɹ lˈɛt ˌɪntʊ ðə kˈæɹɪdʒ, ænd ðɪ ˈʌðɚɹ ˈɛnd ɪz fˈæsənd baɪ tˈuː ˈaɪɚn wˈɛdʒᵻz, wˌɪtʃ ɑːɹ kˈɔːld ðə fˈɔːɹlɑːks, ænd kˈiːz.
They form a part of an arch in the middle, to receive a third part of the thickness of the trunnions; for two thirds of them are let into the carriage, and the other end is fastened by two iron wedges, which are called the forelocks, and keys.