Navigational Instruments found on Ships
Eventually someone noticed that the lodestones were better at pointing out real directions, leading to the first compasses. They designed the compass on a square slab which had markings for the cardinal points and the constellations. The pointing needle was a lodestone spoon-shaped device, with a handle that would always point south. Magnetized needles used as direction pointers instead of the spoon-shaped lodestones appeared in the 8th century AD, again in China, and between 850 and 1050 they seem to have become common as navigational devices on ships. The first person recorded to have used the compass as a navigational aid was Zheng He (1371-1435), from the Yunnan province in China, who made seven ocean voyages between 1405 and 1433.
Compasses were common devices for travelers because they were necessary and practical items. The design of the compass did not change much between the 1600ís and the 1800ís. The compass also was known as a surveying compass or instrument, which was made by some clock makers. The surveying compass was a solar compass, which was different from the magnetic compass. Some compasses were made with wooden supports at the bottom and brass fittings on top. As with many other articles the emigrants had with them, compasses were made in New England states such as Pennsylvania (Schiffer, 352). Compasses were also imported from France and Germany.
The magnetic compass is the oldest instrument for navigation and has been a vital tool for navigators at sea for centuries. The compass allows ships to steer a selected course. By taking bearings of visible objects with a compass, the navigator is also able to fix a ship's position on a chart.
Sextants have been used by numerous nations throughout the world. The sextant was a tool that was used consistently for navigation. Today, it is still being used to navigate the most difficult conditions. The sextant was designed with the knowledge of the weather and ocean currents. With the sextant sailors opened new highly profitable routes for trading, and business.
The lead line was one of the most primitive tools used on clipper ships.
It consisted of a rope or chain with a weighted bucket on the end.
It was dropped off the ship until it hit the bottom. The sailor measured the
rope by fathoms as he let it down. When it hit bottom it collected a small sample
of the sea bottom. They then determined about where they were by
what it picked off the bottom and how deep it was. This also helped them
not to hit the bottom. This device saved many sailor's lives when they
got lost at sea.
The chronometer was a very accurate clock used on clipper ships to
determine their position. Clock makers usually set it to the UTC
(Universal Time Coordinated). To figure their position on the ocean
the navigator noted the time and calculated the position of certain stars.
They then compare these positions with tables that show the star's
position at UTC. It was also called an atomic clock.
The most common navigation instrument found on ships
is the weather vane. They show the wind direction. The
weather vane is very helpful when you lose sight of land.
Sometimes when the wind changed direction the vane
would point a different direction and set the ship off
The Vikings were one of the first to invent the
bearing circle. It was marked with the position
of the sun at sunrise and sunset. It was used to
find the latitude of a ship using a shadow from
a pin. The course was marked by a pointer on
The sun stone was used to find the location of the
sun on days that were very cloudy or stormy. One
disadvantage of the sun stone was that it could only be
used when there was still a little bit of blue sky left. If
there wasn't any clear sky left the sun stone was
The sun board was an instrument used to measure
the height of the sun. By figuring out the angle of the
sun compared to the time of the day sailors could
figure out their position in the sea. During cloudy
weather this instrument was impossible to use
making it hard to navigate.
The anchor was a heavy metal object used on ships. It was used to stop the ship or keep the in one place over night. It was connected to a large chain or rope which was connected to the ship. It was put out and retrieved by a capstan (a large drum turned by wheel-like spokes) which was turned by members of the crew. Without the anchor many ships would float away.