An epitome of navigation, and nautical astronomy, with the improved lunar tables
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Common terms and phrases
angle Answer Apparent Altitude applied bodies called Cape centre chronometer circle Co-secant Co-sine column compass contained correction corresponding course decimal declination departure describe determined diameter Diff difference of latitude difference of longitude direction Dist Dep Dist Lat distance divided draw earth east eclipse equal equator error Examples exceed feet figure given greater Greenwich half head height horizon Horizontal Parallax island latter less logarithm Long longitude lower limb mean meridian method miles minutes month moon moon's motion Nautical Almanac noon object observed orbit parallel passing perp planet polar pole reduce remainder rising RULE sails scale secant seconds ship side sine star subtract sun's Suppose surface Table taken Tangent triangle true variation watch
Page 4 - An improper fraction is one in which the numerator is equal to or greater than the denominator, such as ^ , ^ , or ^ . 4.
Page 171 - To find the logarithm of a number consisting of more than four figures; Take out the logarithm of two numbers, one greater, and the other less, than the number proposed : Find the differ'ence of the two numbers, and the difference of their logarithms : Take also the difference between the least of the two numbers, and the proposed number. Then say, As the difference of...
Page 4 - The number under the line is called the denominator, because it gives name to the fraction ; and the number above the line is called the numerator, because it shows the number of parts used. Thus T\, 10 is the denominator and 3 the numerator.
Page 73 - The earth revolves on its axis in about twentyfour hours : if the moon were stationary, therefore, the same part of our globe would, every twentyfour hours, return beneath the moon ; but as during our daily revolution the moon advances in her orbit, the earth must make more than a complete rotation in order to bring the same meridian opposite the moon : we are three-quarters of an hour in overtaking her.
Page 23 - If a straight line be drawn parallel to one of the sides of a triangle, it shall cut the other sides, or those sides produced, proportionally; and if the sides, or the sides produced, be cut proportionally, the straight '.line which joint the points of section, shall be parallel to the remaining side of the triangle.
Page 6 - RULE. Divide as in whole numbers, and from the right hand of the quotient point off as many places for decimals as the decimal places in the dividend exceed those in the divisor.
Page 52 - The latitudes of places are reckoned from the equator northward and southward, and the longitudes are reckoned upon it eastward and westward. The equator, when referred to the heavens, is called the equinoctial, because, when the sun appears in it, the days and nights are equal all over the world, viz., 12 hours each. The...
Page 53 - ... upon which the rays of the sun fall vertically at the two solstices. These limits, at which the sun appears to stop and then return in the same course, have received the name of tropics.
Page 177 - Then with the latitude and declination, find in the table, the time the star takes in ascending from the horizon to the meridian, and descending from the meridian to the horizon, when the latitude and the declination are of the same name.
Page 7 - The log-line is divided into equal portions, called knots, at each of which a bit of string, with the number of knots upon it, is put through the strands. The length of a knot depends on the number of seconds which the glasses measure, and is thus determined : The No.