3102
THE NEW ZEALAND GAZETTE.
[No. 74

courses you would steer by the standard compass to
make the following courses, magnetic:—

Magnetic courses: N.N.W., S.S.E., W.N.W.,
E.S.E.

Compass courses required:

(c.) Supposing you have steered the following courses
by the standard compass, find the magnetic courses
made from the above curve of deviations:—

Compass courses: N.N.E., E.N.E., S.S.W.,
W.S.W.

Magnetic courses required:

(d.) You have taken the following bearings of two
distinct objects by your standard compass as above:
with the ship’s head at N.E. ½ E., find the bearings,
magnetic:—

Compass-bearings S.E. by S., and — N.N.W.

Magnetic bearings required:

62. Assuming the deviations observed with ship’s head
    by compass to be as follows [or as in Question 61, which-
    ever may be given], determine the value of the coeffi-
    cients A, B, C, D, and E, and from them construct a
    complete table of deviations (or for as many points as
    the Examiner may direct):—

Deviation at North [ ] South [ ]
N.E. [ ] S.W. [ ]
East [ ] West [ ]
S.E. [ ] N.W. [ ]

63. When swinging your ship, if it be required to
    construct deviation tables for two or more compasses
    situated in different parts of the vessel, describe the
    process, and how you would employ the Napier’s dia-
    gram for this purpose.

64. State your rule for determining whether deviation
    is easterly or westerly.

65. Is a knowledge of the value of the various coeffi-
    cients of any advantage? If so, state why.

66. Describe (a) what is commonly known by the
    term “retentive” or “retained” magnetism, and how
    a ship acquires it when in port and at sea; (b) its effect
    on the compass-needle whilst ship’s head continues in
    the same direction; (c) the immediate consequence when
    the direction of the ship’s head is altered; and (d) the
    special precautions to be invariably observed at sea on
    the alteration of the ship’s course.

67. Describe a “dumb-card” or “pelorus,” and its
    use (a) in compensating a compass, (b) in determining
    the deviation.

68. If you determine the deviation by an azimuth or
    an amplitude of a heavenly body, it is then combined
    with variation, which together is sometimes called the
    correction for the compass. State when the deviation
    is the difference between the variation and the correc-
    tion, and when the sum; and when it is of the same
    name as that of the correction, and when of the con-
    trary name.

69. In observing azimuths of heavenly bodies, the
    best method is by “time azimuths,” since these can be
    observed without an altitude when the ship is in port,
    or when the horizon cannot be defined from any cause.
    Give the sun’s declination, the hour of the day, and
    the latitude to find the true bearing of the sun.*

70. By night, if it be desirable to observe the correc-
    tion of the compass: Give the day of the year, and time
    at ship, also the latitude of the place, to determine what
    stars will be in good position for this purpose.

71. If your correcting-magnets are so mounted that
    their positions can be altered, describe the process by
    which, on open sea, you can place the ship’s head mag-
    netic N. (or S.), and magnetic E. (or W.), and can make
    the correction perfect.

72. Given the name of a star, the time, the place of
    ship, the variation of the compass, the bearing of the
    star by compass: determine the deviation, and name if
    east or west.

73. Would you expect any change to be caused in the
    error of your compass by the ship heeling over, either
    from the effect of the wind or the cargo?

74. Describe clearly the three principal causes of the
    heeling error on board an iron ship.

75. Towards which side of the ship would that part
    of magnetism induced in continuous transverse iron
    (which was horizontal while ship was upright) help to
    draw the north point of the needle when the ship heels
    over (a) in the Northern Hemisphere, (b) in the Southern
    Hemisphere?

76. Supposing the compass were placed between the
    two parts of a divided beam or other athwartship iron,
    towards which side of the ship would iron so situated
    help to draw the north point of the needle when ship
    heels over (a) in the Northern Hemisphere, (b) in the
    Southern Hemisphere?

77. Would you expect that part of the magnetism
    induced in iron exactly perpendicular to the ship’s deck,
    such as stanchions, bulkheads, &c., if below the com-
    pass, to cause any part of the heeling error when ship
    heels over, and, if so, towards which side of the ship
    (a) in the Northern Hemisphere, (b) in the Southern
    Hemisphere?

78. If an ordinary standard compass placed higher
    than the iron top-sides be compensated whilst the ship
    is upright, what coefficient will be affected by heeling?

79. Under what conditions—that is, as regards posi-
    tion whilst building, and the arrangement of iron in the
    ship—is the north point of the compass-needle usually
    drawn to windward, or the high side of the ship, in the
    Northern Hemisphere?

80. Under what conditions, as a rule, is the north
    point of the compass-needle usually drawn to leeward,
    or the low side of the ship, in the Northern Hemi-
    sphere?

81. State to which side of the ship, in the majority
    of cases, is the north point of the compass drawn when
    ship heels over in the Northern Hemisphere; and when
    this is the case, and it is not allowed for, what effect
    has it on the assumed position of the ship when she is
    steering on northerly, and also on southerly, courses?

82. On what courses would you keep away and on
    what courses would you keep closer to the wind in both
    the Northern and Southern Hemispheres in order to
    make good a given compass course (a) when north point
    of compass is drawn to windward, or the high side of
    ship, and (b) when drawn to leeward, or the low side.

83. If a ship is beating to windward: when she tacks,
    under what circumstances will the heeling error retain
    the same name, and under what circumstances will it
    take the contrary name?

84. If a ship is placed on the opposite tack by the
    change of wind, the ship’s course being the same by
    compass, will the heeling error change its name?

85. In which direction of the ship’s head does the
    heeling error attain its maximum value, and in what
    direction does it generally vanish?

86. Explain clearly how that part of the heeling error
    due to the permanent part of the magnetism of the ship
    varies as the ship changes her geographical position,
    and what is the reason of this?

87. Explain clearly how that part of the heeling error
    due to the induction in transverse iron (which was hori-
    zontal when ship was upright), and iron vertical to the

*The process of finding time azimuths by the ordinary formula
of spherical trigonometry is tedious, and, since on board an iron
ship these observations should be often repeated, the candidate will
be allowed to use any table or graphic or linear method that will
solve the problem within a half of a degree, the altitude of the
heavenly body not being given.