In the days of the ancient Romans one land mile is equal to 1,000 steps. Later it was established a specific number - 1609 meters. Length nautical mile amounted to 1,852 meters. Where did such a difference?
In order to measure the speed of the vessel, the sailors were uncomfortable to use land miles. Especially, unnecessary risks during emergency operations. From the raging elements during a storm, the lives of seafarers were subjected to great danger. Under such conditions it was not possible to use ground measurements.
So I found a more suitable option. He took a heavy log with a rope and threw it overboard. Then count how many knots pass through the hands of a sailor for a certain period of time until the tension on the rope.
Empirically determined distance between the nodes and the length of time. There are different versions about the precise definition. One of them, when the distance between nodes, averaged 15 meters. In time takes 30 seconds.
It was practical and rational. The countdown was measured by hourglass. It remained only to count the nodes and look at the sand in hours. A task can execute even the illiterate sailor.
Summarized these studies and found. Length from one node to another until the tension on the rope is 15 meters, the time is 30 seconds. Simple arithmetic calculated average vehicle speed. Thus, one nautical mile amounted to 1,852 meters per hour.
With the development of navigation was introduced even greater convenience. One nautical mile equal to one minute of the Meridian. 1 degree equals 60 minutes. On the map it will be 60 nautical miles. The nautical mile became easy to calculate the navigation task.
Therefore, navigators began to measure the distance on the map compass. Attaching it to the degree scale, was used to determine the distance in nautical miles. For example, to get the distance in 30 miles, enough to measure with compasses 30 minutes of arc on any Meridian, marked on the map.
Now, of course, all the equipment is computerized. No need to use deprecated methods, but the nautical mile as unit of distance, remained unchanged and amounted to 1,852 meters. It is called geographic or navigation.
Node is used in navigation as the basic unit of speed. Nautical miles and knots are clear and familiar measurements at sea, such as kilometres and metres on land.
A bit of history...
In order to measure the speed of the vessel, the sailors were uncomfortable to use land miles. Especially, unnecessary risks during emergency operations. From the raging elements during a storm, the lives of seafarers were subjected to great danger. Under such conditions it was not possible to use ground measurements.
So I found a more suitable option. He took a heavy log with a rope and threw it overboard. Then count how many knots pass through the hands of a sailor for a certain period of time until the tension on the rope.
Empirically determined distance between the nodes and the length of time. There are different versions about the precise definition. One of them, when the distance between nodes, averaged 15 meters. In time takes 30 seconds.
It was practical and rational. The countdown was measured by hourglass. It remained only to count the nodes and look at the sand in hours. A task can execute even the illiterate sailor.
Summarized these studies and found. Length from one node to another until the tension on the rope is 15 meters, the time is 30 seconds. Simple arithmetic calculated average vehicle speed. Thus, one nautical mile amounted to 1,852 meters per hour.
Further developments
With the development of navigation was introduced even greater convenience. One nautical mile equal to one minute of the Meridian. 1 degree equals 60 minutes. On the map it will be 60 nautical miles. The nautical mile became easy to calculate the navigation task.
Therefore, navigators began to measure the distance on the map compass. Attaching it to the degree scale, was used to determine the distance in nautical miles. For example, to get the distance in 30 miles, enough to measure with compasses 30 minutes of arc on any Meridian, marked on the map.
Now, of course, all the equipment is computerized. No need to use deprecated methods, but the nautical mile as unit of distance, remained unchanged and amounted to 1,852 meters. It is called geographic or navigation.
Node is used in navigation as the basic unit of speed. Nautical miles and knots are clear and familiar measurements at sea, such as kilometres and metres on land.
