As with everything on this site, if you
come across anything that you think is incorrect or needs
clarification please take a minute to EMAIL ME and let me know
so that I can set it right. |
Astrolabe
A brilliant device used to determine Latitude by observing the altitude and position of the sun, stars, or other planets. |
Backstaff
The Back Staff or Back Quadrant is an navigational instrument that was used to determine latitude by measureing the altitude of the sun in the sky. |
Compass
The most influential invention ever given to the age of Exploration - The Mariner's Compass! |
Compass Rose
Brief history of how the little illustration found on a map or chart identifying the different points of direction came to be. |
Cross Staff
Simple land surveying tool adopted for navigational use at sea |
Lead Line
A weighted line, knotted at fathoms, lowered from the deck of a ship to determine water depth and to take samples from the bottom. |
Log Line
Knotted cord that runs out from a reel to a piece of wood, used to gauge the speed of a vessel at sea. |
Nocturnal
Navigational Instrument used to observe certain stars relative to the pole star in Ursa Minor,
enabling you to discover the hour at night. |
Quadrant
Rare medieval navigational instrument that combined the features of an astrolabe and a quadrant |
Reflecting Circle
19th century navigational instrument in the form of a graduated circle, used at sea to find the longitude by measuring the distance between the spotter and the moon. |
Sand Glass
(a.k.a., Hour glass, sand timer or sand clock)
Information on this clever little device, used to keep time in the age of sail. |
The Sextant
The pinnacle of nautical navigation, the sextant has been used for almost
300 years - even by NASA Gemini missions! |
Traverse Board
Early device used to calculate speed, distance, direction and other navigational essentials in the 16th century. |
The H1, H2, H3, &
ultimately the H4
The story of John Harrison and how he came to invent the tools and methodology to determine a ship's longitude while at sea.
His inventions revolutionized sea travel for more than 250 years! |