The practice of navigation and nautical astronomy. [With] Tables [and] Supplement to the first ed, Volume 261870 |
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Page xi
Henry Raper. The aecessarily too vague to be effective in shaping the course . same applies to Currents , and also to the Marine Barometer ; which , though matters of important consideration in sea - voyages , are not concerned in the ...
Henry Raper. The aecessarily too vague to be effective in shaping the course . same applies to Currents , and also to the Marine Barometer ; which , though matters of important consideration in sea - voyages , are not concerned in the ...
Page 59
... COURSE steered is the angle between the meridian and the ship's head . The course made good is the angle between the meridian and the ship's real track on the surface of the sphere . The course is reckoned from the north , towards the ...
... COURSE steered is the angle between the meridian and the ship's head . The course made good is the angle between the meridian and the ship's real track on the surface of the sphere . The course is reckoned from the north , towards the ...
Page 60
... course steered ( No. 197 ) is the angle NC B , NC being the meridian ; the course made good is NCD , the line CD being determined by producing LC . 203. The DEAD RECKONING is the account kept of the ship's place , without reference to ...
... course steered ( No. 197 ) is the angle NC B , NC being the meridian ; the course made good is NCD , the line CD being determined by producing LC . 203. The DEAD RECKONING is the account kept of the ship's place , without reference to ...
Page 65
... course , which is sometimes expressed in points and sometimes in degrees , is always reckoned from the north or south point , the seaman has to refer at once , in using the Tables , to the number of points , or degrees , in any course ...
... course , which is sometimes expressed in points and sometimes in degrees , is always reckoned from the north or south point , the seaman has to refer at once , in using the Tables , to the number of points , or degrees , in any course ...
Page 68
... course or bearing we have this rule . Rule . When the variation is easterly , apply it to the right of the compass course or bearing ; when westerly , apply it to the left , looking from the centre of the card over the point to be ...
... course or bearing we have this rule . Rule . When the variation is easterly , apply it to the right of the compass course or bearing ; when westerly , apply it to the left , looking from the centre of the card over the point to be ...
Other editions - View all
The Practice Of Navigation And Nautical Astronomy. [with] Tables [and ... Henry Raper No preview available - 2019 |
The Practice Of Navigation And Nautical Astronomy. [with] Tables [and ... Henry Raper No preview available - 2022 |
Common terms and phrases
add the log altitude alts appears azim azimuth bearing called celestial body celestial equator centre chart chronometer circle colat compass Computation corr correction cosec Course and Distance D.Lat decimal decl declination deviation diff difference direction Dist divided employed equal equator error exceeds feet find the Course fraction given gives greater Greenwich Date height of eye Hence horizon interval latitude less logarithms longitude magnetic magnetic bearing measured meridian miles minutes moon moon's multiplied Nautical Almanac nearly observation parallax parallel Parallel Sailing passes Plane Sailing planet pole prime vertical prop quantity radius reckoned reduce refraction result rhumb line right angles Right Ascension sailing Semid sextant shews ship side sine star subtract sum rejecting tens sun's Traverse Table triangle true true alt variation watch
Popular passages
Page 41 - The angle in a semicircle is a right angle ; the angle in a segment greater than a semicircle is less than a right angle; and the angle in a segment less than a semicircle is greater than a right angle.
Page 147 - Since the apparent altitude is too great on account of refraction, and too small on account of parallax, the diff. between these quantities is the diff. between the true and apparent altitudes. This difference, or the combined effect of parallax and refraction, is called the Correction of Altitude. The moon's Corr. of Alt. is given in Table 39; that of a star is merely its refraction. 439. The SEMI-DIAMETER of a celestial body is half the angle subtended by the diameter of the visible disc. Thus...
Page 38 - A parallelogram is a four.sided figure, of which the opposite sides are parallel; and the diameter is the straight line joining two of its opposite angles.
Page 19 - The characteristic of a number less than 1 is found by subtracting from 9 the number of ciphers between the decimal point and the first significant digit, and writing — 10 after the result.
Page 43 - ... section shall be parallel to the remaining side of the triangle. Let DE be drawn parallel to BC, one of the sides of the triangle ABC: then BD shall be to DA, as CE to EA. Join BE, CD; then the triangle BDE is equal...
Page 105 - The distance between two points on the surface of a sphere is the length of the minor arc of a great circle between them.
Page 186 - A line drawn from Polaris perpendicular to the line of the Pointers, and on the opposite side to the Great Bear, passes, at 48° distance, through CAPELLA, one of the brightest stars. In this same line, about the same distance on the opposite side of the pole, is a.
Page 145 - ... of Altitude are circles parallel to the horizon. 431. ZENITH DISTANCE is the arc included between the zenith and the celestial body, or the angular distance of a body from the zenith of which that arc is the measure. The zenith distance is, therefore, the complement of the altitude to 90°, as Z A.
Page 4 - RULE. Multiply all the numerators together for a new numerator, and all the denominators for a new denominator: then reduce the new fraction to its lowest terms.
Page 358 - Frigate La Venus, 1836-9, vol. iii. p. 419) paid particular attention to this indication, and remarks that the observations generally shew a lowering of the thermometer on approaching land, but they disprove that the water on a bank is always colder.* 1039. The temperature of the sea has been observed to change several degrees, in intervals of time varying from a few hours to a day and a half previous to a change of wind, the water becoming gradually warmer when the wind was about to blow from a...