feet, time by chronometer 7 2m, fast 4m 28 for mean noon at Greenwich, July 27th, and losing 21 daily: required the longitude. ADDITIONAL FOR FIRST MATE. 10. 1872, March 21st, mean time at ship 3h 15m P.M., latitude 9° 7′ S., longitude 159° 4′ W., sun's bearing by compass W. S., the observed altitude sun's L.L. 42° 49′ 45", index correction 3' 14", height of eye 21 feet, variation by chart 7° 50' E.: required the error of the compass and deviation. 11. 1872, October 4th, A.M. at ship, latitude account 30° 24′ S., longitude 140° 30′ E., observed altitude sun's L. L. North of observer was 63° 37′ 10", index correction-1′15′′, height of eye 21 feet, time by watch October 3d 22h 37m 158, which had been found to be 1h 10m 20s slow on apparent time at ship, the difference of longitude made to East was 23 miles after the error on apparent time was determined: required the latitude. ADDITIONAL FOR MASTER ORDINARY. 12. 1872, June roth, longitude 25° W., the observed meridian altitude of the star a Cassiopea bearing South, was 85° 0' 20', index correction + 34", height of eye 18 feet required the latitude. 13. Work the day's work on page 259, using the table of deviations at page 138. EXAMINATION PAPER.-No. XIX. FOR SECOND MATE. 1. Multiply 605 by 'co000091, by common logarithms. Divide 117658 by 146.932, by common logarithms. 2. 4. 1872, June 1st, in longitude 44° 40′ E., observed meridian altitude sun's L.L. was 72° 14′ 10′′, zenith North of sun, index correction + 3′ 45′′, height of eye 22 feet: required the latitude. 5. In latitude 62° 39′ N., the departure made good was 25'7: required the diff. long. by parallel sailing. 6. Required the course and distance from Cape Lopatka to Callao. Latitude Cape Lopatka 50° 33' N. Latitude Callao 12 4 S. Longitude Cape Lopatka 156° 46′ E. 77 14 W. 7. 1872, May 4th: find the A.M. and P.M. tides at Aberdeen, Dunbar, and Wick. 74. 1872, December 10th: find the times of high water A.M. and P.M. in longitude 45° W., change tide 3h 12m. 76. 1869, December 13th: find the A.M. and P.M. tides at Fécamp (Admiralty Tide Tables). 8. 1872, August 10th, at 7h 10m A.M, apparent time at ship, latitude 55° 10' S., longitude 156° E., sun rose by compass E. 11° 20' S. (ship's head due West, deviation 11° 30′ W.): required the variation. 9. 1872, January 29th, P.M. at ship, latitude at noon 28° 45′ N., observed altitude sun's L.L. 17° 46′ 30′′, index correction - 3′ 25′′, height of eye 16 feet, time by a chronometer, January 28d 16h 31m 30s, which was slow 1m 3s for mean noon at Greenwich, January 1st, and losing 993 daily, course since noon N.W. by W. (true), dist. 20 miles: required the longitude of ship at noon. THE SAME, AS PROPOSED AT LIVERPOOL. 1872, January 29th, at about 4h 1m P.м. at ship, latitude at noon 28° 45′ N., longitude account 171° E., observed altitude sun's L.L. 17° 46' 30", index correction 3' 25", height of eye 16 feet, time by chronometer 4h 31m 30s, slow 1m 3s on January 1st, and losing 93 daily, course since noon N.W. by W. (true), distance 20 miles: required the longitude at the time of observation, and also at noon. ADDITIONAL FOR FIRST MATE. 10. 1872, June 15th, mean time at ship 7h 15m A.M., latitude 52° 25′ N., longitude 2° 18' E., sun's bearing by compass S. 78° 56' E., observed altitude sun's U.L. 29° 56′ 40′′, index correction + 34", height of eye 18 feet, variation by chart 21° W.: required the error of compass and deviation. II. 1872, November 29th, P.M. at ship, latitude account 6° 20' S., longitude 123° 25′ E., observed altitude of sun's L,L. 72°, index correction + 4' 0", eye 19 feet, time by watch November 28d 22h 46m, which had been found to be 1h 53m slow on apparent time at ship, the difference of longitude made to West was 12'3, after the error on apparent time was determined: required the latitude. 12. ADDITIONAL FOR MASTER ORDINARY. 1872, May 15th, the observed meridian altitude of the starb Orionis 52° 20' 30", zenith North of star, index correction 4' 10", height of eye 15 feet: required the latitude. -- 13. Work the day's work on page 260, using the table of deviations, page 138. 4. 1872, October 1st, in longitude 84° 40′ E., observed meridian altitude sun's U.L., bearing North, was 57° 20' 30", index correction - 3′ 36', height of eye 17 feet: required the latitude. 5. A ship from latitude 35° 30′ S., longitude 27° 28′ W., sailing due East (true) 301 miles required the compass course steered, and what will be the longitude in, variation point E., and deviation 8° 50' E. 6. Required the course and distance from A to B. 7. Latitude A 10' 8' S. Latitude B 23 12 N. Longitude A 175° 18′ E. Longitude B 141 15 E. Variation point West, and deviation 7° 15′ W. 1872, August 1st: find the times of high water A.M. and P.M. at Leith Pier, Tay Bar, Rye Bay, and Dunkerque. 7a. 1872, May 3rd: find the times of high water A.M. and P.M. in longitude 40° W., change tide 2h 30m. 76. 1869, August 20th: find the A.M. and P.M. tides at Sheerness (Admiralty Tide Tables). 8. 1872, May 11th, at 5h P.M. apparent time at ship, latitude 38° 50′ S., longitude 139° 25′ E., sun setting by compass W.N.W., variation by chart 5° 8′ E.: required the error of compass and deviation. 9. 1872, August 24th, A M. at ship, latitude at noon 37° 59′ N., observed altitude of sun's L.L. 37° 13′ 30′′, index correction + 2' 40", height of eye 18 feet, time by chronometer, August 24d 6h 8m 138, which was 4m 6s slow on Greenwich mean noon, August 1st, and losing 119 daily, course since observation N.N.W,, 22′4 (true): required the longitude at noon. THE SAME, AS PROPOSED AT LIVERPOOL : 1872, August 24th, at about 8h 40m A.M. at ship, latitude at noon 37° 59′ N., longitude account 143° 45′ W., observed altitude sun's L.L. 37° 13' 30", index correction + 2' 40", height of eye 18 feet, time by chronometer 6h 8m 135, which was 4m 63 slow on Greenwich mean noon, August 1st, and losing 119 daily, course since observation N.N.W., 22'4 (true): required the longitude at noon. ADDITIONAL FOR FIRST MATE. 10. 1872, February 27th, mean time at ship 5h 25m P.M., latitude 37° 20′ S., longitude 14° 10' W., sun's bearing by compass W. by N. 4 N., observed altitude sun's U.L. 14° 50′ 30, index correction - 1′ 3′′, height of eye 19 feet: required the variation. 11. 1872, May 29th, A.M. at ship, latitude account o° 31' N., longitude 150° 40′ W., observed altitude of sun's L.L., North of observer, was 67° 41′, index correction + 1', height of eye 20 feet, time by watch 29d 3h 32m, which had been found to be 4h 28m fast on apparent time at ship, the difference of longitude made to the East was 26'9 after the error on apparent time was determined: required the latitude, ADDITIONAL FOR MASTER ORDINARY. 12. 1872, June 17th, the longitude 98°W., observed meridian altitude of a Serpentis, zenith South of observer, was 29° 0′ 40′′, index correction + 4' 20", height of eye 24 feet required the latitude. 13. At the Cape of Good Hope the variation is about 28° W., if the sun at noon bear due North by compass, what is the deviation? DESCRIPTION OF A SEXTANT. A SEXTANT is constructed on the same principles as a quadrant, and furnishes the means of measuring the angle between two objects in whatever direction they may be placed, so that the angle does not exceed 140°. BC is the arc or limb which is graduated from o° to about 140° (from C towards B), and each degree in the best instruments is again sub-divided into six equal parts of 10' each, while the vernier g used in estimating the sub-divisions of the arc shows 10". The divisions are also continued a short distance on the other side of zero (o), towards C, forming what is termed the arc of excess, for the purpose of determining the index error in the manner that will be subsequently explained. The microscope M, and its reflector r secured at the point d by a movable arm dr to the index A E, may be adjusted to read off the divisions on the graduated limb and the vernier g. The index A E is secured to the arc B C by the intervention of a clamp screws at its back, which must be loosened when the index has to be moved any |