Old-Time Nautical Instruments

The essay surveys early maritime navigational instruments and their practical use from medieval astrolabes and cross-staffs through Davis quadrants to later developments, explaining how each worked, their limitations, and incremental improvements toward reflected instruments and the sextant. It discusses compasses, nocturnals, ring-dials, and shipboard adaptation, notes wood and brass construction, the craftsmanship of instrument makers, and records surviving examples and markings. Practical descriptions emphasize observational procedures, challenges of accuracy, and the gradual replacement of older tools by liquid-filled compasses and improved optical devices.