In describing headgear, Julius explains that a hat should have ventilation to permit the free flow of air by convection.
ɪn dᵻskɹˈaɪbɪŋ hˈɛdɡɪɹ, dʒˈuːlɪəs ɛksplˈeɪnz ðˌæɾə hˈæt ʃˌʊdəv vˌɛntɪlˈeɪʃən tə pɚmˈɪt ðə fɹˈiː flˈoʊ ʌv ˈɛɹ baɪ kənvˈɛkʃən.