1490
THE NEW ZEALAND GAZETTE.
[No. 43

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 compass, 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 co-efficient will be affected by heeling?

79. Under what conditions (that is, as regards position 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 Hemisphere?

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 horizontal when ship was upright), and iron vertical to the ship’s deck, varies as the ship changes her geographical position.

88. What, then, would be the probable nature of the heeling error—that is, whether to high or low side of the ship; and whether the error would be equal to the sum or difference, &c., of the forces given (1) in high north latitude, (2) on magnetic equator, (3) in high south latitude?—assuming the polarity of the sub-permanent magnetism of the ship under and affecting the compass to be as given below; the vertical induction in soft iron, of course, obeying the ordinary laws in the above geographical positions (1), (2), (3) :—

(a.) In cases where the effect of red vertical sub-permanent magnetism is equal to that of the vertical induction in the soft iron of the ship:

(b.) Where the effect of red vertical sub-permanent magnetism is greater than that of the vertical induction in the soft iron:

(c.) Where the effect of red vertical sub-permanent magnetism is less than that of the vertical induction in the soft iron.

(d.) Where the effect of blue vertical sub-permanent magnetism is equal to that of the vertical induction in the soft iron:

(e.) Where the effect of blue vertical sub-permanent magnetism is greater than that of the vertical induction in the soft iron:

(f.) Where the effect of blue vertical sub-permanent magnetism is less than that of the vertical induction in the soft iron.

89. Can the heeling error be compensated? If so, state the means to be employed, and how the compensation may be effected.

90. Can the compensation of the heeling error be depended on in every latitude? If not, state the reason.

91. Do the soft-iron correctors used for compensating the co-efficient + D have any effect on the compass-needle when the ship heels over, and, if so, do they draw the needle towards the low or the high side of the ship, and do they counteract, or otherwise, the effect produced by the vertical induction in the soft iron, (a) in the Northern Hemisphere, (b) in the Southern Hemisphere; and what is the reason of this?

92. Given the heel, the direction of the ship’s head by compass, and the heeling error observed, to find the approximate heeling error, with a greater or less given heel, and with the ship’s head on some other named point of the compass, the ship’s magnetic latitude being in both cases the same.

93. Describe any instrument to show the ship’s heel (generally called a clinometer), and state how and where it should be fixed.

94. Should the clinometer be observed when the ship is swung to determine the deviation when the ship is upright? If so, state the reason why.

95. Would you expect the table of deviations supplied by the compass-adjuster from observations made in swinging the ship to remain good during the voyage, or would you expect the deviations to change? If so, state under what circumstances.

96. Is it desirable that a record of your observations for deviations should be kept as a guide for any subsequent voyage in case the ship should be in the same locality, or for further corrections of the compass? If so, describe some suitable form for keeping such record.

97. Would you under any circumstances consider it a safe and proper procedure to place implicit confidence in your compasses, however skilfully they may have been adjusted? If not, what precautions is it your duty to take at all times?

APPENDIX I.

DEVIATION OF THE COMPASS.

FOR MASTERS’ CERTIFICATES FOR HOME-TRADE SHIPS.

The applicant must answer in writing, on paper given him by the Examiner, all the following questions numbering his answers to correspond with the numbers of the questions:—

1. When taking a meridian altitude, how do you know when the sun is on the meridian; or, in other words, when it is noon?

2. How does the sun bear (true and magnetic) when on the meridian of an observer in these latitudes (home-trade limits)?