The sector on a quadrant, or, A treatise containing the description and use of three several quadrants; : each rendred many wayes both general and particular. Accommodated for dyalling, for the resolving of all proportions instrumentally, and for the ready finding the hour and azimuth universally, in the equal limb. Of great use to seamen, and practitioners in the mathematiques. Written by John Collins accountant, and student in the mathematiques. Also an appendix touching reflected dyalling, from a glass however posited. With large cuts of each quadrant, printed from the original plates graved by Henry Sutton, either loose, or pasted upon boards.