Even the least reli­gious among us speak, at least on occa­sion, of the cir­cles of hell. When we do so, we may or may not be think­ing of where the con­cept orig­i­nat­ed: Dan­te’s Div­ina Com­me­dia, or Divine Com­e­dy. We each imag­ine the cir­cles in our own way — usu­al­ly fill­ing them with sin­ners and pun­ish­ments inspired by our own dis­tastes — but some of Dan­te’s ear­li­er read­ers did so with a seri­ous­ness and pre­ci­sion that may now seem extreme. “The first cos­mo­g­ra­ph­er of Dante’s uni­verse was the Flo­ren­tine poly­math Anto­nio Manet­ti,” writes the Pub­lic Domain Review’s Hunter Dukes, who “con­clud­ed that hell was 3246 miles wide and 408 miles deep.” A young Galileo sug­gest­ed that “the Inferno’s vault­ed ceil­ing was sup­port­ed by the same phys­i­cal prin­ci­ples as Brunelleschi’s dome.” In 1855, the aris­to­crat sculp­tor-politi­cian-Dante schol­ar Michelan­ge­lo Cae­tani pub­lished his own pre­cise artis­tic ren­der­ings of not just the Infer­no, but also the Pur­ga­to­rio and Par­adiso, in La mate­ria del­la Div­ina com­me­dia di Dante Alighieri dichiara­ta in VI tav­ole, or The Divine Com­e­dy of Dante Alighieri Described in …