By Author
Gamal Adnan
the Arabs used these stars, which seemed fixed in the measurement, which was considered the foundation of the art of navigation in the Indian sea, the captain defined the position by stars and measured the distance by zam, it was mental science and it transferred supported by experiments, Arab concluded astronomy from astrology, and astronomical knowledge spread, which led to measurement exactly so that site of Equator was agreed the zijs and maps today, they invented the collections of wood to measure the height of the star, they drew circle of compass and set with stars then divided to two halves the right half for the sunrise and the other for sunset, and just every star was far away from the other eleven and a quarter degree or standard seven fingers, and set conditions for the measure in order to avoid error and fear of difference of measurement.
In spite of the arrange of travel dates, but it was full of surprises as typhoons whirlwind and high waves, when the wind is blowing in the reserve direction the water turned to revolving water, which destroyed ships, the ships met the dangers of shallow bays and difficult turnings eruptive waves and the strike the fire, the revolving water carried ships over the highest mountain, suddenly they descended quickly and destroyed, the sky became dark, the colors and marks faded, the sailors could not use the compass the service asterisk useless, they were attacked by the ships of pirates, human flesh eaters and large fierce animals in the sea and land. It was put pyramidal system, the master captain sat on the top who richened naval knowledge by practical experiences knowledge oceanography, which led to the long distance voyage was known as absolute circle, which was considered the foundations of pure experimental navigation liberated, so they rescued their knowledge of classical theories and took their experiences and expertise as foundation, they knew the signs, that told about occurrence of difficult or easy navigation this science led them to invent the star circle, which drove them to penetrate into the sea because it was a map of the sky, the people experts of the sea had been guided and supported thus by wooden pieces for measurement, which was made on the basis of the finger as an unit of measurement, which led to
compile the guide books [rahmanagate], ordinary captains studied, worked and executed them. they transferred pictures of societies and aspects of holidays, celebrations and sorrows for us, the sailors represented the base of pyramid, who carried the real effort on their shoulders and was defined for each member a function precisely.
The Omani sailors Permanent gained the experience so that they became skilled navigators because they practiced many times, these long travel of sailing, the experiences and science enabled them to know the kind of wood that was suit for the shipping industry, timbers, masts, or oars, teak was used for making the ships, coconut wood to make masts, coconut coir was used for sewing craft, ships and caulking by gum powder and whale oil, thick cottony cloth or Doum palm fronds were used for making sails and straw mats thick leather was used to cover deck ships, granite was used for making anchors, iron was used for making rings in order to fix the sail, arrows and axes, Marco polo said: that ships had continue more than a hundred years, contributed to the experience in engineering of shipbuilding, they know the nature their seas, that had got high temperature and salinity, which led to the corrosion of iron ,nails were broken when the .coral reef collided the ships, so they used coconut fiber instead of nails
