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PAPER XII.—Continued.

1884. August 1st. August 1st. Find the time of High Water at Bordeaux, A.M. and P.M.

1885. April 16th, 5h 38 A.M. apparent time at ship in lat. 27° 51' N.; Long. 109° 10' W.; the sun's observed amplitude was E. 6° N. Required the True Amplitude and Error of the Compass; and supposing the variation to be 13° E., required the Deviation.

1885. June 14th, P.M. at ship in lat. 31° 10' N.; the observed altitude of the sun's lower limb was 49° 0' 10"; height of eye 18 feet. Time by a chronometer June 14d 12h 15m 40s, which was 4" 365 fast on mean noon at Greenwich on January 2nd, and on March 13th it was 9 165 fast for mean noon at Greenwich. Required the Longitude.

ADDITIONAL FOR ONLY AND FIRST MATES.

1886. January 1st, mean time at ship 4" 12" P.M. in lat. 31° 48′ S.; long. 176° 25' E.; the sun's bearing by compass WN., observed altitude of sun's lower limb 34° 47' 50"; height of eye 16 feet. Required the True Azimuth and Error of Compass; and supposing the variation to be 20° E., required the Deviation.

1885. October 19th, P.M. at ship lat. by account 50° 37' S.; long. 13° E.; the observed altitude of the sun's lower limb 49° 10′ 30′′ North of the observer; height of the eye 24 feet. Time by Watch 19a oh 5m 575, which was found to be 10m slow on apparent time at ship. The difference of longitude made to the Eastward was 17 miles after the error on apparent time at ship was determined. Required the Latitude by the Reduction to the meridian.

ADDITIONAL FOR MASTER.

1885. April 11th. The observed meridian altitude of the star "Sirius" bearing North, was 61° 3' 50"; height of the eye 16 feet. Required the Latitude.

NAPIER'S DIAGRAM.-PAPER XII.-Continued.

ADDITIONAL FOR MASTER.

In the following table give the correct magnetic bearing of the distant object, and thence the deviation.

CORRECT MAGNETIC BEARING :

[blocks in formation]

With the deviation as above, give the courses you would steer by the standard compass to make the following courses, correct magnetic.

Correct magnetic course S E by E., WS.
N 70° E.

Compass courses

Suppose you have steered the following courses by the standard compass, find the correct magnetic courses made from the above deviation table.

Compass courses, East, N W by W., S W.

Magnetic courses

You have taken the following bearings of two distant objects by your standard compass as above; with the ship's head at S E E., find the bearings, correct magnetic. Compass bearings NW., W § N.

Bearings, magnetic

SUMNER'S METHOD.

FOR MASTER, FIRST MATE AND ONLY MATE. If at sea on June 21st, 1885, P.M., and uncertain of my position, when the Chronometer showed 21d 4h 0TM o Greenwich Mean Time, the observed Altitude of the Sun's L. L. was 47° 21′ 21′′, and again P.M. the same day, when

PAPER XII.-Continued.

the Chronometer showed 21d 6h 57m 485 Greenwich Mean Time, the observed Altitude of the Sun's L. L. was 17° 0′ 56′′ the ship having made 27 miles on a true NE by E. course in the interval, height of eye 22 feet. Required the line of position when the first altitude was taken; also the bearing of the sun, 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° 40′ N. and 47° 10' N.

FOR MASTER, FIRST MATE AND ONLY MATE.

Magnetic Chart.

1. Using deviation card No.

find the course to

steer by compass from K to C, also the distance.

2.

-With the ship's head on the above-named compass course, a [point [lighthouse] L bore by compass S 75° W, and A bore N 4° 43′ E. by the same compass. Find the ship's position.

3-With the ship's head as above, a [point] [lighthouse] E bore by compass N 52° E, and after continuing on the same course 21 miles, it bore S 88° 6' E. Find the ship's position, and her distance from E, at the time of taking the second bearing.

ADDITIONAL FOR MASTERS.

4. Find the course to steer by compass from K to C (see question 1.) to counteract the effect of a current, which set NNE E. (correct magnetic) at the rate of 3 miles per hour, the ship making by log 7 miles per hour; also the distance the ship will then make good in 9 hours towards C.

5.-On September 30th, 1884, at II P.M., being off Ballycastle Bay, 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.

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