English mathematician. Wrote extensively on mathematical subjects. His first publication was a speech in praise of the study of mathematics and its applications to astronomy, navigation, geography, topography, hydrography, and the military art (A Copie of the Speache ..., London, 1588). Later published major works on elementary and practical geometry (Elements of Geometrie, London, 1590), and on scientific instruments including the cross-staff, proportional compasses, and celestial and terrestrial globes.