Lighthouse..

Lighthouse on small scale chart. Old light tower.

Rook awash at low water.......✶ Sunken rock

Life Saving Station..........

telegraphic system.

Kelp.................

LSS. (T)...........signifles connection with

or add word white or yellow as required.

INTERNATIONAL CODE.

This code consists of 27 flags, as follows: 2 burgees, 5 pennants, 19 square flags and the code penuant, making 27 in all and are described as follows:

Code pennant, red and white in 5 alternate stripes.

E

R-d-white-blue, in three vertical stripes.

F Red, with white right cross.

J

Blue-white-blue, in three horizontal stripes.

K Yellow-blue, in two vertical stripes.

L

Blue and yellow in four alternate checks.

M Blue, with white diagonal cross.

N Blue and white in sixteen alternate checks.

Y

Yellow and red in ten diagonal stripes.

Black-yellow-blue-red, each color triangular shaped.

To open communication, show the ensign with the Code Pennant under it.

When using the Code Pennant as an Answering Pennant, hoist i by itself where best seen.

To Find Longitude by a Star.

In this observation, the altitude is observed and corrected the same as in that of the sun, except that in dealing with stars, parallax and semi-diameter are not taken into account because they are too small for consideration.

The time by chronometer is noted and corrected in the usual way. If the Greenwich time should be P. M., it is astronomical time as it stands. If it is A. M., add twelve hours to it and put the date back one day.

The declination is taken from pages 248, 249 or 250, of the Nautical Almanac, and if it has the sign+, it is north, and if the sign is —, the declination is south.

The declination requires no correction, and when taken from the Nautical Almanac, is at once applied to ninety degrees to obtain the polar distance.

From the same page of the Nautical Almanac from which the declination is taken, the star's right ascension I will be found.

In this observation it is better to use the astronomical date, which is fully explained in dealing with the Pole Star.

From the last column on page II of the Nautical Almanac, take the sidereal time. Enter Table 9 with the Greenwich mean time of observation expressed astronomically, and take out the corresponding correction and add it to the above mentioned sidereal time. The result will be the correct sidereal time.

Add together the true altitude, latitude and polar distance, and divide the sum by two. The result will be the

half sum and from the half sum, subtract the true altitude to obtain the remainder.

Take from Table 44 the logarithms, the same as in the observation of the sun, and find the hour angle which must always be taken from the P. M. column of Table 44.

If the star is west of the meridian, add its right ascension to the hour angle; but if the star is east of the meridian, subtract the star's hour angle from the star's right ascension, and if the right ascension is too small, add twenty-four hours to it, and the result will be the right ascension of meridian. From the right ascension of meridian, subtract the corrected sidereal time or right ascension of mean sun; but if the right ascension of meridian is too small, add twenty-four hours to it, and the result will be the local astronomical mean time at ship. The difference between the local astronomical mean time and Greenwich astronomical mean time will be the longitude in time, and this is turned into degrees, etc.

It is not probable that the examiners will give the applicant this problem, either to work or write about. However, they can if they wish to.

Latitude by Meridian Altitude of a Fixed Star.

The star's meridian altitude is observed. Correct it for instrumental error, dip and refraction which will give the true altitude. Subtract the true altitude from ninety degrees and the result will be the zenith distance and is named contrary to the star's bearing. If the zenith distance and declination from pages 248, 249 or 250, of the Nautical Almanac are both north or both south, add them together and their sum will be the latitude. If one is north and the other south, their difference will be the latitude and takes the name of the greater.

Among navigators it is customary to compute the time the desired star will pass the meridian and its approximate meridian altitude.

To find the time a star will pass the meridian, subtract the sun's right ascension, from page I of the Nautical Almanac, from the star's right ascension, and the result will be the local apparent time of the star's meridian passage. If the local mean time of the star's meridian passage is required, use the sidereal time from page II of the Nautical Almanac, instead of the sun's right ascension. If the star's right ascension is less than that of the sun, it must be increased by twenty-four hours.

To compute the meridian altitude, subtract the latitude by account from ninety degrees, which will give the colatitude. If the latitude and declination are of same name, add the declination to the co-latitude. If they are of different name, take their difference and the result will be the true meridian altitude. To this add the dip and refraction and apply the instrumental error contrary to