How to Use Plastic Sextants with Applications to Metal Sextants and a Review of Sextant Piloting

How to Use Plastic Sextants with Applications to Metal Sextants and a Review of Sextant Piloting PDF Author: David Burch
Publisher:
ISBN: 9780914025245
Category : Sports & Recreation
Languages : en
Pages : 106

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Book Description
Sextants are used to measure angular heights of celestial bodies above the horizon to find the latitude and longitude of the observer. They can also be used on land with artificial horizons. Sextants can also be used to find the correct Universal Time by measuring the angular distance between the moon and another body along its path across the zodiac. In coastal waters or on land, sextants can be used for very accurate piloting by measuring the horizontal angles between charted landmarks. The vertical angle of a peak above its baseline determines the distance to it, which, combined with a compass bearing, yields a position fix from just one landmark. The angular dip of an object (island or vessel) below the visible horizon can also be used to determine the distance to it. This booklet explains how to get the best results from plastic sextants, and presents numerical comparisons with similar data from metal sextants. Sextant piloting techniques are also reviewed as they are an ideal use of a plastic sextant.

How to Use Plastic Sextants with Applications to Metal Sextants and a Review of Sextant Piloting

How to Use Plastic Sextants with Applications to Metal Sextants and a Review of Sextant Piloting PDF Author: David Burch
Publisher:
ISBN: 9780914025245
Category : Sports & Recreation
Languages : en
Pages : 106

Get Book Here

Book Description
Sextants are used to measure angular heights of celestial bodies above the horizon to find the latitude and longitude of the observer. They can also be used on land with artificial horizons. Sextants can also be used to find the correct Universal Time by measuring the angular distance between the moon and another body along its path across the zodiac. In coastal waters or on land, sextants can be used for very accurate piloting by measuring the horizontal angles between charted landmarks. The vertical angle of a peak above its baseline determines the distance to it, which, combined with a compass bearing, yields a position fix from just one landmark. The angular dip of an object (island or vessel) below the visible horizon can also be used to determine the distance to it. This booklet explains how to get the best results from plastic sextants, and presents numerical comparisons with similar data from metal sextants. Sextant piloting techniques are also reviewed as they are an ideal use of a plastic sextant.

The Barometer Handbook

The Barometer Handbook PDF Author: David Burch
Publisher:
ISBN: 9780914025122
Category : Nature
Languages : en
Pages : 238

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Book Description
A modern look at barometers and applications of barometric pressure.

Emergency Navigation

Emergency Navigation PDF Author: David F. Burch
Publisher: International Marine/Ragged Mountain Press
ISBN: 9780071565585
Category : Navigation
Languages : en
Pages : 0

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Book Description
"Emergency Navigation is far more generally applicable than the title indicates. It is, first and foremost, a detailed account of how to find your position anywhere in the world's oceans after your electronics fail and you lose your sextant, watch, and almanac, but that's really only the beginning. The book is chock-full of good sound navigational techniques and principles that will serve you well regardless of where and under what conditions you are sailing. Hopefully you will never be confronted by the need for emergency navigation, but even the most pleasurable sailing afternoon can be enlivened by a knowledge of the skills and methods taught in this book. Each chapter presumes a fundamental understanding of navigational principles, then deepens and expands that understanding to embrace little-known techniques and makeshfit instruments. Beginning with the assumption that preparing for a navigational emergency is good seamanship, Burch presents detailed discussions on finding time and place at sea; determining direction; steering by wind and swells; steering by the stars; steering by the sun; and steering by other objects in the sky. You will also find chapters on steering under conditions of reduced visibility; piloting in currents; dead reckoning; latitude and longitude; and no-instrument coastal piloting. A final summary tells you what to do in any situation with what you have available at the time. David Burch writes lucidly, and the text is well supported by 127 detailed illustrations. This book offers excellent insights into sound seamanship that will serve you well in all your sailing activities. "A standout in the otherwise faceless navigation texts that passthrough our offices. Anyone venturing offshore should read this book thoroughly."--"Yachting Magazine "Opens the way to pleasurable understanding in a definitive work of instant appeal to seamen of all levels of experience. Full insights into nautical astronomy rarely seen in standard works. . . . Full of sound seamanship for coastal and open water mariners alike."--"The Navigation Foundation "Gives one a deeper understanding of the basic principles of navigation . . . a great store of knowledge which may serve you well in an emergency but will also give much pleasure off watch whilst improving your seamanship in the process."--"British Cruising Association Bulletin "Thorough and authoritative. . . . chapters on steering by the stars, sun, and moon stir the imagination and make one want to be a thousand miles from land . . . Gives us a better understanding of the signposts above the horizon than we might gain from a lifetime of random gazing."--"Sea Kayaker Magazine "Far more than an essay on the principles and practice of emergency navigation, it is a particularly well-written account of the principles of navigation in general and as such cannot fail to bring fresh insights to all of us. Every section and paragraph is permeated with sound practical seamanship . . . Apart from its other virtues, this alone makes it worthwhile."--from the foreword by David Lewis (author of "We, the Navigators and "Ice Bird) "Clearly written in a readable fashion . . . the work is so well thought out and covers so many possibilities that both a beginner and the most experienced navigator will find something of value in its pages. Worth every penny of its cost."--"The Burgee Magazine

Cognition in the Wild

Cognition in the Wild PDF Author: Edwin Hutchins
Publisher: MIT Press
ISBN: 0262581469
Category : Psychology
Languages : en
Pages : 403

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Book Description
Edwin Hutchins combines his background as an anthropologist and an open ocean racing sailor and navigator in this account of how anthropological methods can be combined with cognitive theory to produce a new reading of cognitive science. His theoretical insights are grounded in an extended analysis of ship navigation—its computational basis, its historical roots, its social organization, and the details of its implementation in actual practice aboard large ships. The result is an unusual interdisciplinary approach to cognition in culturally constituted activities outside the laboratory—"in the wild." Hutchins examines a set of phenomena that have fallen in the cracks between the established disciplines of psychology and anthropology, bringing to light a new set of relationships between culture and cognition. The standard view is that culture affects the cognition of individuals. Hutchins argues instead that cultural activity systems have cognitive properties of their own that are different from the cognitive properties of the individuals who participate in them. Each action for bringing a large naval vessel into port, for example, is informed by culture: the navigation team can be seen as a cognitive and computational system. Introducing Navy life and work on the bridge, Hutchins makes a clear distinction between the cognitive properties of an individual and the cognitive properties of a system. In striking contrast to the usual laboratory tasks of research in cognitive science, he applies the principal metaphor of cognitive science—cognition as computation (adopting David Marr's paradigm)—to the navigation task. After comparing modern Western navigation with the method practiced in Micronesia, Hutchins explores the computational and cognitive properties of systems that are larger than an individual. He then turns to an analysis of learning or change in the organization of cognitive systems at several scales. Hutchins's conclusion illustrates the costs of ignoring the cultural nature of cognition, pointing to the ways in which contemporary cognitive science can be transformed by new meanings and interpretations. A Bradford Book

Lost Enlightenment

Lost Enlightenment PDF Author: S. Frederick Starr
Publisher: Princeton University Press
ISBN: 0691165858
Category : History
Languages : en
Pages : 694

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Book Description
The forgotten story of Central Asia's enlightenment—its rise, fall, and enduring legacy In this sweeping and richly illustrated history, S. Frederick Starr tells the fascinating but largely unknown story of Central Asia's medieval enlightenment through the eventful lives and astonishing accomplishments of its greatest minds—remarkable figures who built a bridge to the modern world. Because nearly all of these figures wrote in Arabic, they were long assumed to have been Arabs. In fact, they were from Central Asia—drawn from the Persianate and Turkic peoples of a region that today extends from Kazakhstan southward through Afghanistan, and from the easternmost province of Iran through Xinjiang, China. Lost Enlightenment recounts how, between the years 800 and 1200, Central Asia led the world in trade and economic development, the size and sophistication of its cities, the refinement of its arts, and, above all, in the advancement of knowledge in many fields. Central Asians achieved signal breakthroughs in astronomy, mathematics, geology, medicine, chemistry, music, social science, philosophy, and theology, among other subjects. They gave algebra its name, calculated the earth's diameter with unprecedented precision, wrote the books that later defined European medicine, and penned some of the world's greatest poetry. One scholar, working in Afghanistan, even predicted the existence of North and South America—five centuries before Columbus. Rarely in history has a more impressive group of polymaths appeared at one place and time. No wonder that their writings influenced European culture from the time of St. Thomas Aquinas down to the scientific revolution, and had a similarly deep impact in India and much of Asia. Lost Enlightenment chronicles this forgotten age of achievement, seeks to explain its rise, and explores the competing theories about the cause of its eventual demise. Informed by the latest scholarship yet written in a lively and accessible style, this is a book that will surprise general readers and specialists alike.

Fundamentals of Kayak Navigation

Fundamentals of Kayak Navigation PDF Author: David Burch
Publisher:
ISBN:
Category : Sports & Recreation
Languages : en
Pages : 296

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Book Description


The Anatomy of the Gyroscope

The Anatomy of the Gyroscope PDF Author: Frank W. Cousins
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 304

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Book Description


Far Travelers

Far Travelers PDF Author: Oran W. Nicks
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 276

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Book Description


Above the Pacific

Above the Pacific PDF Author: William Joseph Horvat
Publisher:
ISBN:
Category : Transportation
Languages : en
Pages : 234

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Book Description


Celestial Navigation

Celestial Navigation PDF Author: David Burch
Publisher:
ISBN: 9780914025511
Category : Sports & Recreation
Languages : en
Pages : 296

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Book Description
This book has been used for 30 years, updated periodically as needed. More than 20,000 students have successfully learned ocean navigation from these materials and gone on to cross oceans or circumnavigate the globe. This book covers how to find position at sea from timed sextant sights of the sun, moon, stars, and planets plus other routine and special procedures of safe, efficient offshore navigation. No previous navigation experience is required. The only math involved is arithmetic (adding and subtracting angles and times). This is a practical, how-to-do-it book, which also includes clear explanations of how it works and how to do it well. Plus this book includes other crucial factors of ocean navigation besides just finding out where you are from the stars, such as logbook procedures, dead reckoning, error analysis, route planning, and more. At the end of this book, you will be ready for ocean navigation. The book includes: text, practice problems, tables selections, detailed glossary, and full solutions. Printable work forms, plotting sheets, and other resources are available at no charge from www.starpath.com/celnavbook. Preface to the Second Edition: We are pleased to say that after ten more years of using this text we do not find reason to change the basic approach and methods of the teaching. We still use most of the same examples, which are now quite old, but that is the beauty of celestial navigation. It has not changed, so we do not benefit in any way from making all new examples, which would bring with them more chance of error in a book of many numbers. We have, however, notably improved and expanded the book. Each section has been updated and reformatted for a clearer presentation, often in response to student questions over the years. New graphics have been added and older ones all updated. There is much new content in the text, especially in the In-Depth chapter, including more detailed discussion of the sailings and more background on the principles. New sections were added on general ocean navigation and optimizing the fixes. We have also updated the electronic navigation section, as most ocean navigators will also be using other tools besides celestial.