Isaac Barrow (London 1630 - Cambridge 1677) mathematician and scholar, holder of the chair of geometry at the University of Gresham, was the first to be assigned the "Lucasian Chair of Mathematics" at the University of Cambridge. He played a leading role in the English scientific world, in particular he is remembered for his work on the calculation of the tangent. He was the author of important treatises including these two editions, of the first four books on the conic sections of Apollonius of Tyana and on the sphere of Theodosius accompanied by his observations.