669
mercurial, corrected". It is of great importance that readings of the ship's barometer made in Hong Kong should be forwarded by post or messenger whenever possible. The correction determined at the Royal Observatory from these readings will always be forwarded to the master upon request. A brief explanation of the International Code is appended. Extra copies of this notification may be obtained on written or personal application to the Director, Royal Observatory, who will at all times be pleased to give every possible information to any shipmaster or officer.
International Meteorological Code.
In the International Code figures are used in groups of five, the significance of the figures depending upon the group in which they occur and their position in the group. For the purpose of radio transmission in the China Sea the necessary groups are as below.
Land Stations.
Fig.
Group 1 1st
2nd
3rd
4th
5th
Index number of station or designating letters as per list.
Barometric tendency-Table IX
Past weather-Table VII
Group 2 1st
Direction of wind-Table III
2nd
3rd
Force of wind-Table V
4th
Present weather-Table VI
5th
Group 3 1st
2nd
{Barometer in millibars or inches-Table VIII
3rd
Visibility-Table XII
4th
5th
Temperature, whole degrees Fahrenheit.
Ship Stations.
Fig.
Group 1 1st
Day of the week-Table I
2nd
Octant of the Globe (unnecessary--use letter X)
3rd
4th
Latitude in degrees and tenths
5th
Group 2 1st
2nd
örd f
4th
5th
Longitude in degrees and tenths--omit initial 1 if long. is 100° or
more.
G. M. T.-prefixing 0 if below 10 hours.
Group 3 As Group 2 for Land Stations.
Group 4 As Group 3 for Land Stations.
"X" is to be used in place of the appropriate figure when the information is not available.