Libra astronomica ac philosophica : qua Galilaei Galilaei opiniones de cometis a Mario Gvidvcio in Florentina Academia expositae, atque in lucem nuper editae, examinantur
Libra astronomica ac philosophica is a 1619 Latin treatise printed at Perugia by Orazio Grassi, a Jesuit astronomer, answering Galileo's views on comets for scholars of natural philosophy. Its pictures are small woodcut ornaments and diagrams: a decorated initial, a roundel of a bird, a sealed-sphere apparatus with lettered points, and a hand adjusting a stand-mounted instrument. A designer could draw on the crisp black line work and the tidy diagram lettering.
