Charles Hertz, age 13, of Allentown., Penna.:
What is dead reckoning
Out in the middle of the ocean, one wave looks very like the next, Way up in the airs one cloud looks very like the next, Certainly neither one special wave nor one special cloud can show you the way home, A sailor or pilot who knows his dead reckoning does not have to ask his directions from the waves or the clouds. He has mastered the skills of finding his way by tried and tested detective work,
No, dead reckoning has nothing to do with crime detection. There is no dead body in the picture. From time to time the navigator writes the letters D.R. on his chart, Actually, they stand for deduced reckoning. He uses the term dead reckoning for short.
Magellan did not use dead reckoning to find his way around the world... He took his bearings and figured his directions from the sun and the stars, This method of keeping on course is called celestial navigation ‑ steering by the heavenly bodies, The north star always points out the north direction, the sun rises more or less in the east and sets more or less in the west.
Unlike Magellan, the modern pilot knows exactly where he is going and the shortest way to get there. He could not dream of setting forth without a carefully prepared chart of his course. He uses this chart to keep check of his dead reckoning. The‑sailor may steer himself by a familiar landmark to get clear of the harbor. This is called coasting. A pilot may guide his plane by a mountain or tall tower. This is called contact flying, But once out in the wide open spaces, the sailor or the flyer turns his attention to deduced reckoning,
He may call this detective work instrument flying. For he relies upon. instruments to guide him. A compass is there to show the directions, He uses this to steer and keep his ship on course. Another instrument tells his speed and the number of miles he has already traveled. A special clock tells how time is going. This and maybe other information is checked every few hours, The result is marked with D. R. on the chart prepared for the course,
Clouds may hide the sun and stars, making celestial navigation impossible But the skilled pilot is safely on course so long as he faithfully keeps up his dead reckoning. Suppose he is blown off course by storms and strong winds, Then he turns to other instruments to find his new position. He waits for a view of the heavens, Then he checks with the sun and stars, he has an almanac that tells his exact position from this information. His special clock tells him latitude from time, Even when lost, the skilled dead reckoner can get back on course and find his way home.