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PAPER XI.

(SECOND MATE as far as Longitude by chronometer.) Multiply 723.36 by 875.52 by common logarithms. Divide 100000 by .016 by common logarithms.

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1885. March 25th, in long. 120° 30' W.; the observed meridian altitude of the sun's lower limb was 61° 0' 10" bearing North; index error-3' 10"; height of eye 15 feet. Required the Latitude.

In lat. 46° 32' N., the departure made good was 114.2 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 46° 10' S.
Lat. of B 46 53 N.

Long. of A 15° 50′ W.
Long. of B 14 59' W.

1884.

PAPER XI.-Continued.

November 18th.

at Newhaven A.M. and P.M.

Find the time of high water

1885. November 9th, at 5h 51 P.M., apparent time at ship in lat. 28° 51' N.; long. 13° 46' W.; the sun's 51′ observed amplitude was W. N. Required the True Amplitude and Error of the Compass; and supposing the variation to be 26° W., required the Deviation.

1885. September 1st, A.M. at ship in lat. 47° 50' N.; the observed altitude of the sun's lower limb was 39° 49' 0"; height of eye 17 feet. Time by a chronometer August 31d 10h 15m 203, which was 6" 50s slow on mean noon at Greenwich on May 1st, and losing 3.5 daily. Required the Longitude.

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ADDITIONAL FOR ONLY AND FIRST MATES.

1885. March 20th, A.M.; Mean Time at Greenwich 19d 23h 49m os in lat. 43° 15' N.; long. 33° W.; the sun's bearing by compass S. W.; observed altitude of the sun's lower limb 35° 6' 15"; height of eye 12 feet. Required the True Azimuth and Error of the Compass; and supposing the variation to be 27° W., required the Deviation.

1885. May 12th, A.M. at ship, lat. by account 39° 50′ S. ; long. 160° 28' 15" E.; the observed altitude of the sun's lower limb 31° 48′ 50′′ North of the observer; height of the eye 12 feet. Time by chronometer 11a 12h 58m58, which was 4m 59s slow on Mean Time at Greenwich. Required the Latitude by the Reduction to the Meridian.

ADDITIONAL FOR MASTER.

1885. December 27th. The observed meridian altitude of the star "Deneb" (Cygni) bearing North, was 56° 20' 10"; height of eye 19 feet. Required the Latitude.

Find the Index Error and Sun's Semidiameter from the following readings of the Sextant: 31' 50" on and 32' 10" off.

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NAPIER'S DIAGRAM-PAPER XI.-continued.

ADDITIONAL for Master.

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

CORRECT MAGNETIC BEARING:

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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, NE by N., West,
S 82° W.

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, E S E., N 46° W., E by S.
Magnetic courses,

You have taken the following bearings of two distant objects by your Standard Compass as above; with the Ship's head at N E by E., find the bearings, correct magnetic.

Compass bearings, N by E., E by S.

Bearings magnetic,

SUMNER'S METHOD.

FOR MASTER, FIRST MATE AND ONLY MATE. If at sea on June 30th, 1885, A.M., and uncertain of my position, when the Chronometer showed 29a 23h 14485 Greenwich Mean Time, the observed Altitude of the Sun's L. L. was 62° 27′ 24′′, and again P.M. the same day,

PAPER XI.—Continued.

when the Chronometer showed 30d 2h 57" 125 Greenwich Mean Time, the observed Altitude of the Sun's L. L. was 47° 34' 0", the ship having made 24 miles on a true W by N N. 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, 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° 45′ N. and 49° 5' N.

FOR MASTER, FIRST MATE AND ONLY MATE.

Magnetic Chart.

I. Using deviation card No.

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find the course to

steer by compass from S to F, also the distance.

2. With the ship's head on the above-named compass course, a [point] [lighthouse] [point] [lighthouse] A bore by compass S 85° 56' E. and C bore N 1° 33′ W. by the same compass. Find the ship's position.

3.

-With the ship's head as above, a [point] [lighthouse] A bore by compass S 49° 22' E., and after continuing on the same course 25 miles, it bore S 15° 19' W. Find the ship's position, and her distance from A, at the time of taking the second bearing.

ADDITIONAL FOR MASTERS.

4. Find the course to steer by compass from S to F (see question 1.) to counteract the effect of a current, which set S E by E E., at the rate of 2 miles per hour, the ship making by log 12 miles per hour; also the distance the ship will then make good in 5 hours towards F.

5.-On November 11th, 1884, at 10h 5m P.M., being off Tenby, 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 XII.

(SECOND MATE as far as Longitude by Chronometer.) Multiply 8497.5 by 24.4 by common logarithms. Divide 4276000 by 12790 by common logarithms.

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1885. November 9th, in long. 64° 10' W.; the observed meridian altitude of the sun's lower limb was 24° 1′ 20′′ bearing S.; index error-3' 10"; height of eye, 15 feet. Required the Latitude.

In Lat. 44° 20' S. the departure made good was 44.2 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 9° 2' N.
Lat. of B I 2 S.

Long. of A 171° 19′ W.
Long. of B 83 17 E.

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