PAPER IV.-Continued. G.M.T., the observed Altitude of the Sun's Sun's L.L. II° 38′ 28′′, and again A.M., the same day when the Chronometer shewed 13 21h 53m 225 G.M.T, the observed Altitude of the Sun's L.L. 45° 51′ 6", the ship having made 30 miles on a true E.S.E course in the interval, height of eye 20 feet. Required the line of position when the first Altitude was taken, also the bearing of the Sun by projection, and the position of the ship by Sumner's Method when the second Altitude was observed. The ship being supposed to be between the parallels of 48° 30' N. and 48° 50' N. True Chart. 1. Using deviation card No. find the course to steer by Compass from M to D, also the distance. 2. With the ship's head on the above-named compass course, a [point] [lighthouse] E bore by compass S.E. and L bore S.W. by the same compass. Find the ship's position. 3.—With the ship's head as above, a [point] [lighthouse] F bore by compass N.E. by N., and after continuing on the same course 20 miles, it bore N.N.W. Find the ship's position, and her distance from F, at the time of taking the second bearing. ADDITIONAL FOR MASTERS. 4. Find the course to steer by compass from M to D (See Question 1.) to counteract the effect of a current, which set East (true) at the rate of 2 miles per hour, the ship making by log 7 miles per hour; also the distance the ship will then make good in 10 hours towards D. 5.-On December 19th, 1884, at 2h 49" A.M., being off Arklow, by reckoning took a cast of the lead. Required the correction to be applied to the depth obtained by the lead line before comparing it with the depth marked on the Chart. PAPER V. (Second Mate as far as Longitude by Chronometer.) Multiply 98400 by 6.5 by common logarithms. 1885. S. S.S.E. W.N.W. I 20° 20′ E. Variation 28° 8′ W. S.S.W. 124° 10' E. W.S.W. I° o' W. S.W. 11° 40′ W. A current set the ship N.N.E.E., correct magnetic, IO miles during the day. September 22nd, in long. 115° 30' W.; the observed meridian altitude of the sun's lower limb was 62° 10' 20" bearing North; index error 2' to subtract; height of eye 17 feet. Required the Latitude. In lat. 60° the departure made good was 30 miles. Required the difference of longitude by parallel sailing. Required the course and distance from A to B on Mercator's principle. Lat. of A 23° 30' S. Long. of A 15° 15′ E. PAPER V.-Continued. 1884. April 10th. Find the time of high water at Glasgow, A.M. and P.M. 1885. December 24th, at 10" 51" A.M., apparent time at ship in lat. 65° N.; long. 35° 35' W.; the Sun's observed amplitude was S. W. Required the true amplitude and error of the compass; and supposing the variation to be 1° 10' E., required the Deviation. 1885. May 13th, A.M., at ship in lat. 55° o' N.; the observed altitude of the sun's lower limb was 23° 50' o"; height of eye 14 feet. Time by a chronometer May 13d 1h 6m os, which was 2" 10 fast for mean noon at Greenwich, on March 10th, and gaining 2.5° daily. Required the Longitude. ADDITIONAL FOR ONLY AND FIRST MATES. 1885. August 28th, A.M., mean time at Greenwich 27d 13h 17m 0s, in lat. 32° 25′ N.; long. 100° E.; the sun's bearing by compass East; observed altitude of sun's lower limb 29° 47′ 50′′; height of eye 19 feet. Required the True Azimuth and Error of Compass; and supposing the variation to be 7° 44′ W., required the Deviation. 1885. August 20th, A.M., at ship, lat. by account 40° 2' N.: long. 79° 20′ W.; the observed altitude of the sun's lower limb 61° 55′ 0′′ south of the observer; height of eye 21 feet. Time by chronometer 20d 6h 8m 555, which was 59 30 fast on Mean Time at Greenwich. Required the Latitude by the Reduction to the Meridian. ADDITIONAL FOR MASTER. 1885. May 31st. The observed meridian altitude of star "Vega" bearing North was 60° 3' 50", height of the eye 24 feet. Required the Latitude. PAPER V.-Continued. NAPIER'S DIAGRAM. ADDITIONAL FOR MASTer. In the following Table give the correct magnetic bearing of the distant object, and thence the deviation. CORRECT MAGNETIC BEARING: With the deviation as above, give the courses you would steer by the standard compass to make the following courses, correct magnetic. Correct magnetic courses E by N., WS., N 50° W. Suppose you have steered the following courses by the standard compass, find the correct magnetic courses made from the above deviation table. Compass courses N E., S 41° W., N W. You have taken the following bearings of two distant objects by your standard compass as above; with the ship's head at E NE E. find the bearings, correct magnetic. Compass bearings NW., E by N. SUMNER'S METHOD. FOR MASTER, FIRST MATE, AND ONLY MATE. If at Sea on September 23rd, 1885, A.M., and uncertain of my position when the chronometer shewed 22d 21h 20m 1s G.M.T., the observed altitude of the Sun's L.L. 28° 41′ 32′′, PAPER V.-Continued. ་ and again P.M., on the same day, when the chronometer showed 23d 1h 36m 40s, G.M.T., the observed altitude of the Sun's L.L. 40° 30' 5", the ship having made 25 miles on a true N WW. course in the interval, height of eye 18 feet. Required the line of position when the first altitude was taken, also the bearing of the sun by projection, and the position of the ship by Sumner's Method when the second altitude was observed. The ship being supposed to be between the parallels of 46° 10' N. and 46° 40' N. FOR MASTER, FIRST MATE, AND ONLY MATE. True Chart. 1. Using deviation card No. steer by compass from H to G, also the distance. 2. With the ship's head on the above-named compass course, a [point] [lighthouse] C bore by compass S 26° 41′ E. and B bore N 83° E. by the same compass. Find the ship's position. 3. With the ship's head as above, a [point] [lighthouse] O (O is the centre of the compass) bore by compass S. 74° 30' E., and after continuing on the same course 20 miles, it bore S 40° 45' E. Find the ship's position, and her distance from O, at the time of taking the second bearing. ADDITIONAL FOR MASTERS. 4. Find the course to steer by compass from H to G (See Question 1.) to counteract the effect of a current, which set N W (true) at the rate of 2 miles per hour, the ship making by log 4 miles per hour; also the distance the ship will then make good in 6 hours towards G. 5.-On October 23rd, 1884, at oh 58m A.M., being off Douglas, by reckoning took a cast of the lead. Required the correction to be applied to the depth obtained by the lead line before comparing it with the depth marked on the Chart. |