Navigational+Tools-EM

Latitude Hook

The latitude hook is a device that can show you which way to go to get to another island if that island is in your same latitude. Sailors used it to sail from one island to another. This device is made up of two bamboo sticks. One stick is longer than the other. The longer stick is also split and it ends in a hook. The two sticks are tied together at a right angle. The reason the latitude hook worked is because of the stars. If the sailor could see Polaris while looking the right way, then he knew he was on the same latitude as when he had started. That meant he knew he was going the right way.

Kamal

The kamal was used by the Arabs. The kamal is a small wooden board with a hole drilled through the middle. A knotted string would be strung through the hole. The lengths of the string stood for different latitudes. It worked the same as the latitude hook but was much more efficient.

Astrolabe

The astrolabe was also used by the Arabs. This device worked the same as the latitude hook and kamal but was much more elaborate. This device was said to be the first scientific instrument used for navigation. The astrolabe is believed to originate from Greece. Later on, the Arabs refined it into a more sophisticated device. This device is a disk with the degrees of an arc marked around its circumfrence. Other parts of the astrolabe are the sight vanes and the alidade which is commonly made of brass. This device is hung vertically from a ring. The person using the device holds it above his head. He then aligns the alidade so the star or planet he is measuring by can be seen in a straight line through the sight vanes. The angle of this line of view was then read by the alidade and converted in to the latitude.