## American Practical NavigatorU.S. Government Printing Office, 1821 - Nautical astronomy |

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I think this book is wonderful with rich talents of a boy and the way he looks at things.

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### Common terms and phrases

a-head Aldebaran anchor angle apparent altitude arch bearing and distance brace cable calculated centre Co-secant co-sine Co-tang column compass correction corresponding Degrees Degs Diff difference of latitude difference of longitude Dist Distſ equal EXAMPLE feet Funchal given Greenwich haul head sails horizon glass Horizontal Parallax larboard Latitude and Departure lee-way line of numbers logarithm mast meridian altitude method middle latitude miles mizen moon moon's Nautical Almanac nearly noon º º observed altitude ºc ºc ºil parallel perpendicular plane Plane Sailing radius refraction rope round sails sea account Secant semi-diameter sextant ship ship's side sine star starboard staysail subtracted sun's declination sun's right ascension Table tack Tangent telescope tide topsails triangle true tude variation veer wind windward yard zenith distance

### Popular passages

Page 6 - In any triangle, the sum of the three angles is equal to two right angles, or 180°.

Page 116 - ... or taking their difference when of contrary names ; the altitude to be reckoned from the south point of the horizon, when the latitude is north, and the contrary when south ; but when the sum exceeds 90°, it is to be taken from 180°...

Page 182 - To find the solidity of a pyramid and of a cone. RULE. — Multiply the area of the base by one third of its altitude, and the product will be its solidity.

Page 199 - The cause of the. tides is the unequal attraction of the sun and moon upon different parts of the earth. . For they attract the parts of the earth's surface nearest to them, with a greater force than they do its centre : and attract the centre more than they do the opposite surface. To restore this equilibrium the waters take a spheroidal figure, whose longer axis is directed towards the attracting luminary.

Page 28 - To find the logarithm of a vulgar fraction. RULE. Subtract the logarithm of the denominator from the logarithm of the numerator...

Page 204 - ... the miles the current sets per hour, and the bearing of the log will show the set of it. There is a very remarkable current, called the GULF STREAM, which sets in a north-east direction along the coast of America, * From Nathaniel Bowditch, THE NEW AMERICAN PRACTICAL NAVIGATOR, E.

Page 13 - TO THEIR DIFFERENCE ; So IS THE TANGENT OF HALF THE SUM OF THE OPPOSITE ANGLES', To THE TANGENT OF HALF THEIR DIFFERENCE.

Page 584 - In spherical triangles, whether right angled or oblique angled, the sines of the sides are proportional to the sines of the angles opposite to them.

Page 183 - If the vessel be double-decked, take the length thereof from the fore part of the main stem, to the after part of the stern post, above the upper deck ; the breadth thereof at the broadest part above the main wales...