The mathematical iewel, [electronic resource] : shewing the making, and most excellent vse of a singuler instrument so called: in that it performeth with wonderfull dexteritie, whatsoeuer is to be done, either by quadrant, ship, circle, cylinder, ring, dyall, horoscope, astrolabe, sphere, globe, or any such like heretofore deuised: yea or by most tables commonly extant: and that generally to all places from pole to pole. The vse of which iewel, is so aboundant and ample, that it leadeth any man practising thereon, the direct pathway (from the first steppe to the last) through the whole artes of astronomy, cosmography, geography, topography, nauigation, longitudes of regions, dyalling, sphericall triangles, setting figures, and briefely of whatsoeuer concerneth the globe or sphere: with great and incredible speede, plainenesse, facilitie, and pleasure: the most part newly founde out by the author, compiled and published for the furtherance, as well of gentlemen and others desirous of speculatiue knowledge, and priuate practise: as also for the furnishing of such worthy mindes, nauigators, and traueylers, that pretend long voyages or new discoueries: / by John Blagraue of Reading gentleman and well willer to the mathematickes, who hath cut all the prints or pictures of the whole worke with his owne hands. 1585.