. A new treatise on the practice of navigation at sea : containing all the details necessary to enable the mariner to become a good practical navigator. . where the Course is required, consider whether the DiflTerence of Latitude or the Departor*is the ereatest. If the Depsirture is the greatewt, the Course is found at the bottom of the page; but if the Departur*Is ^he least of the two, the course will be found at the Top of the page. Because those Tables are calculated as far aa Four Points or 45 at the Top, for Distance, DiflTerence of Latitude, andDeparture; they then commence at the Bottom
. A new treatise on the practice of navigation at sea : containing all the details necessary to enable the mariner to become a good practical navigator. . where the Course is required, consider whether the DiflTerence of Latitude or the Departor*is the ereatest. If the Depsirture is the greatewt, the Course is found at the bottom of the page; but if the Departur*Is ^he least of the two, the course will be found at the Top of the page. Because those Tables are calculated as far aa Four Points or 45 at the Top, for Distance, DiflTerence of Latitude, andDeparture; they then commence at the Bottom of the page, and go backwards for tiio remaining Points or Degrees ofthe Quadrant, and the angle of the Course beips jrreater, the Latitude and Departure columns are reversed at fh<» BoV, and miUKet voordipi?!. 12 PLANE SAILING. CASE V. The Course and Departure given to find the Distance and Difference of Latitude. Example.—A Ship from Lat. 2° 7 N sails South-West by West half West until she has made 8fi0 inOtf «iDeparture. Required her Latitude in and Distance Sailed. Fig. 10. Latitude left 2° T of ~Q S. PROJECTION BY THE PLANE SCALE. Draw a horizontal line to represent the parallel of Latitude sailed from. Take the Chord of 60° in th«dividers, and with one foot on this line as a Centre, make the Arc of a Circle towards the left downwards,which will represent the South-West quarter of the Compass. Take 90° in the dividers, and with one footon the line where the Circle joins it, extend the other and mark the Circle. A line through this mark tothe Centre will form a Right Angle with the other line, and which will represent the Meridian sailed 5^ Points from the line of Chords, and lay it off from the South towards the West, and mark it on theCircle. Draw the Rhumb line through this mark to the Centre, and it will form an Angle with theMeridian or the Course. Lay off the Departure 350 miles from the Meridian towards the Wes
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectnavigat, bookyear1902
