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DAY'S WORK

Example 2.-A ship had Fire Island light bearing N. N. E. distant 10-5/10 miles, ship's head S. 12 W. Variation 10° oo' W. Deviations as per table on page 16. Throughout the 24 hours a current set N. E. magnetic and its drift 78 mile per hour. The ship was sailed as follows:

COURSE
E. by S. 12 S.
S. by W. 1/2 W.

S. E. 12 S.
S. 12 W.

S. S. E.
S. E. by S.

WIND
S. by E.

S. E.
S. S. W.
W. S. W.

W.
W. N. W.

LEEWAY 1/2 pt. 1/2 pt. 1/2 pt. 1/2 pt. 14 pt.

DISTANCE

40'.2 36.7 38.5 39.4 56.3 63.6

Find the course and distance made good and the ship's position. From that point find the course and distance to Cape Henry light.

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9.9

3.6

5 S. 20°00 W. E. bv S. 4, s. s. by E. 32 pt. 1o W. 23 30 W. 40. 2 .67 45 E. 15.1 S.by W.42 W. S. E. * pt. 10 W. 15 00 E 36. ? S. 27 30

Io.

37'.3

16.9

S.S. W.

100 W. | 78 30' E

W S. E. & S. S. S. W. pt. 10 W. 21 45 W. 38. 5 S. 76 45 E. S. 42 W. W. S. W. W pt. 10 W. 7 30 E. 39. 4 S. 2 30 E.

S. S. E. W. 2 pt. 10 W. 14 00 W. 56. 3 S. 49 Ty E. S. E. by S. W.N. W. 10 W. 20 oo W. 63. 6 S. 63 45 E. N. E.

21. 0 N. 35 oo E. 17.2

32.5

8.7 39.4 36.6 27.9

37.5

1.7 42.5 57.2 I 2.0

10 W,

20.5

32.3 155.0 188.5

32.3

20.5

122.7 168.0

MIDDLE LATITUDE SAILING BY INSPECTION

Dir. lat. 163.0.}

=Co. S. 54° E. dist. 208'.

Lat. Fire I. L. 40° 37' 57" N. Long. Fire I. L. 73° 13'08" W. Dif. 122.7 =- 2 02 42 S. Dif. 217'.5=

3 37 30 E. Lat. ship

38 35 15 N. Long. ship 69 35 38 W. Lat. Fire I. L. 40° 37' 57" N. Lat. ship

+ 38 35 15 N.

2)79 13 12 Middle lat. = 39 36 36 Middle lat. 39°1/2 dep. 168'.o = dif. long. 217'.5=3° 37' 30" E.

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Co. S. 72° 03' W.
Prop. dif. lat.
Dist.

sec. 99'.7 323.5

.51119 +1.99870 = 2.50989

PRACTICAL DEAD RECKONING

The traverse table is not used in the practice of navigation, but its use must be learned that more practical means may be used to keep account of a ship's track.

Usually the following method is not wanted at an examination, bụt should be used in practice. The former is quite satisfactory so far as the final result is concerned, which is not known until the end of the day. By this the ship's position may be known at any moment. In other words, by one the ship takes the man and by the other the man takes the ship. +

Lat. Fire I. 40° 38'. N.

Long. Fire I. Dif.

9.9 S. =4oo dep. 3.6 = dif.
Lat. noon
40 28.1 N.

Long. noon
Dif.

15.1 N. =41 dep. 37.3= dif.
Lat. 4 P.M.
40 43.2 N.

Long. 4 P.M.
Dif.

32.5 S. = 40 dep. 16.7= dif.
Lat. 8 P.M.
40 10.7 N.

Long. 8 P.M.
Dif.

8.7 S. = 40 dep. 37.5 = dif.
Lat. Mdt.
40 02 .0 N.

Long. Mdt.
Dif.
39.4 S. = - 40 dep.

1.7= dif.
Lat. 4 A.M.
39 22.6 N.

Long. 4 A.M.
Dif.

36.9 S. = 39 dep. 42.8= dif.
Lat. 8 A.M.
38 45.7 N.

Long. 8 A.M.
Dif.

27.9 S. = 39 dep. 57.2 = dif.
Lat. noon
38 17.8 N.

Long. noon
Dif. (current) + 17.2 N. = 38 dep. 12.0= dif. (current)
Lat. noon
38 35.0 N.

Long. noon

73° 13'.1 W. +

4.7 W.
73 17.8 W.

49.4 E.
72 28.4 W.
+

21.8W.
72 50.2 W.

49. E.
72 0I .2 W.

2.2 E.
71 59.0 W.

55.8 E.
71 03.9 W.
I 13.6 E.
69 50.3 W.

15.2 E. 69 35.1 W.

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