This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 Excerpt: ...is the same as the latitude of the point on the line A', R/J 25 19'.4 S. B115 31.5 W. We now have two Sumner linee, A'and B', under Case I, whose common latitude is 25 19MS., and whose longitudes on the common parallel are 114 61K.7 and 115 31'.5. Hence, the difference of longitude on the common parallel is 115 31'.5 W. 114 59'.7 W. CHAPTER XVI. THE PEAOTIOE 01 NAVIGATION AT SEA. 381. Having set forth in previous chapters the methods of working dead reckoning and of solving problems to find the latitude, longitude, chronometer correction, and azimuth from astronomical observations, it will be the aim of the present chapter to describe the conditions which govern the choice and employment of the various problems, together with certain considerations by which the navigator may be guided in his practical work at sea. 382. Departure And Dead Reckoning.--On beginning a voyage, a good departure must, be taken while landmarks are still in view and favorably located for the purpose; this becomes the origin of the dead reckoning, which, with frequent new departures from positions by observation, is kept up to the completion of the voyage, thus enabling the mariner to know, with a fair degree of accuracy, the position of his vessel at any instant. At the moment of taking the departure, the reading of the patent log (which should have been put over at least long enough previously to be regularly running) must be recorded, and thereafter at the time of taking each sight and at every other time when a position is required for any purpose, the log reading must also be noted. It is likewise well to read the log each hour; for general information as to the speed of the vessel as well as to observe that it is in proper running order and that the rotator has not been fouled ...

used for study of celestial navigation. This is the 1981 edition volume 2.

used for study of celestial navigation. This is the 1981 edition volume 2.

This is the completely NEW EDITION of The American Practical Navigator Vol 2. "I am honored to welcome you to the 2017 edition of Publication No. 9, The American Practical Navigator, or as most mariners refer to it, "Bowditch." As a young Surface Warfare Officer serving in my first ship, I quickly learned Bowditch should be my first resource for all things related to navigation, oceanography and meteorology. I never imagined that 25 years later, I would be privileged to lead the team entrusted with updating this incredible document. One can hardly imagine the time, effort, and pressure involved in undertaking such a task--this is Bowditch, after all. None of us alone can equal the talent, experience and skill of Nathaniel Bowditch, as expressed in his first edition of 1802. As a result, this edition is the outcome of countless hours of hard work by many dedicated, passionate, and skilled colleagues from a variety of disciplines. And it was this team of scientific and operational navigation experts, led by Dr. Jerry Clifford, which has created this contemporary edition that stands ready to address the challenges faced by today's navigators and mariners. Please take the time to read the long list of contributors to this edition, I know you will be impressed by the depth and quality of our team. Since the last edition, there have been huge advancements in positioning methodologies and navigation systems. In some cases, what was old is new again, so we focused considerable effort into improving the celestial navigation and piloting chapters. Hand-plotting latent fixes on paper charts has been overtaken by Electronic Chart Display and Information Systems that continuously tell you where you are, provide warnings when standing into danger, and display radar and Automatic Identification System information to heighten situational awareness. Older graphics have been replaced by newer, higher resolution images to better illustrate the purpose of the text. Needless to say, we are justifiably proud of this 2017 edition and equally honored to continue such a noteworthy legacy of the navigational expertise first introduced by Nathaniel Bowditch 215 years ago. Wherever you may sail, I trust this fine resource will assure your safe passage. I wish you all fair winds and following seas. CAPT Brian D. Connon, CAPTAIN U.S. NAVY" EXPLANATION OF NAVIGATION TABLES. Mathematical Tables Table 1. Logarithms of Numbers TABLE 2. NATURAL TRIGONOMETRIC FUNCTIONS TABLE 3. COMMON LOGARITHMS TABLE 4. TRAVERSE TABLES CARTOGRAPHIC TABLES TABLE 5. NUMERICAL CHART SCALES TABLE 6. MERIDIONAL PARTS TABLE 7. LENGTH OF A DEGREE OF LATITUDE AND LONGITUDE PILOTING TABLES TABLE 8. METERS, FEET, AND FATHOMS TABLE 9. C NAUTICAL AND STATUTE MILES TABLE 10. SPEED TABLE FOR MEASURED MILE TABLE 11. SPEED, TIME, AND DISTANCE TABLE 12. DISTANCE OF THE HORIZON TABLE 13. GEOGRAPHIC RANGE TABLE 14. DIP OF THE SEA TABLE 15. DISTANCE BY VERTICAL ANGLE OBJECT BEYOND SEA HORIZON TABLE 16. WATERLINE AT OBJECT AND TOP OF OBJECT TABLE 17. DISTANCE BY VERTICAL ANGLE TABLE 18. DISTANCE OF AN OBJECT CELESTIAL NAVIGATION TABLES TABLE 19. TABLE OF OFFSETS TABLE 20. MERIDIAN ANGLE AND ALTITUDE TABLE 21. LATITUDE AND LONGITUDE FACTORS TABLE 22. AMPLITUDES TABLE 23. CORRECTION OF AMPLITUDE TABLE 24. ALTITUDE FACTORS TABLE 25. CHANGE OF ALTITUDE IN TABLE 26. TIME ZONES, TABLE 27. CORRECTION FOR AIR TEMPERATURE TABLE 28. ALTITUDE CORRECTION METEOROLOGICAL TABLES TABLE 29. THERMOMETER SCALES TABLE 30. DIRECTION AND SPEED OF TRUE WIND IN UNITS OF SHIP'S SPEED TABLE 31. CORRECTION OF BAROMETER READING FOR HEIGHT TABLE 32. CORRECTION OF BAROMETER TABLE 33. CORRECTION OF BAROMETER READING TABLE 34. CONVERSION TABLE TABLE 35. RELATIVE HUMIDITY TABLE 36. DEW POINT CHAPTER 1. MATHEMATICS CHAPTER 2. INTERPOLATION CHAPTER 3. NAVIGATIONAL ERRORS CHAPTER 4. CALCULATIONS AND CONVERSIONS CHAPTER 5. COMPASS CONVERSIONS CHAPTER 6. COMPASS ERROR

Data in this book are no longer valid for navigation. It is preserved in print because many training programs (including USCG and US Navy ) use examples from 1981 to teach celestial navigation. USCG license exams require data from this almanac. These exams also require Sight Reduction Tables, Pub 229, Vol. 2 and a 2102-D Star Finder.