3 



10. Arrangement of Supplemental Data (8) and explanation of symbols. — 



XI 

 XI 

 oj 





o 



s 

 O 



•a 



o 



<! 

 



s 



03 



FIFTH GROUP— Symbols 3C.C M C a N: 



3 — Group index: This is a code figure to identify the supplemental data being used. For these supplemental data, 

 the code figure is always 3. 

 C,, — Form of low cloud: See Code Table XIII. Example: "Cumulo-nimbus" — code figure 3. 



C M — Form of middle cloud: See Code Table XIV. Example: "Alto-cumulus, in bands, increasing" — code figure 5. 

 C H — Form of upper cloud: See Code Table XV. This relates only to forms of cirrus or cirro-stratus clouds. Example: 

 "Cirrus, fine, increasing" — code figure 4. 



N — Cloud amount: See Code Table XVII. Amount of sky covered by clouds, recorded in tenths. Example: "0.7 to 

 0.8" — code figure 5. 



SIXTH GROUP— Symbols t d KdWN t : 



t d — Temperature difference {air and water): See Code Table XVIII. Difference between temperature of air and tem- 

 perature of water at or near surface. Example: "Air 4° lower" — code figure 7. 

 K — Swell: See code Table XIX. Character of swell. Example: "Heavy swell, long" — code figure 8. 

 d — Direction of swell: See Code Table IV. True direction from which swell is moving. Example: "SW" — code 

 figure 5. 



W — Past weather: See Code Table VII. General characteristics of weather during 3 hours preceding the observation. 

 Example: "Showers" — code figure 7. 



Ni. — Amount of lower cloud: See Code Table XVII. Proportion of sky covered by lower clouds recorded in tenths. 

 Example: "Sky completely covered by lower clouds" — Code figure 8. 



SEVENTH GROUP— Symbols d.fabb: 



d„ — Course of ship: See Code Table IV. General direction toward which ship is moving, recorded to 8 cardinal points. 

 Example: "NE" — code figure 1. 

 f — Ship's speed: See Code Table XX. Speed of ship in knots per hour. Example: " 22 to 24 knots " — code figure 8. 

 a — Barometer characteristic: See Code Table X. Characteristic of change in the barometer in the last 3 hours. Ex- 

 ample: " Barometer unsteady but falling, now lower than 3 hours ago " — code figure 7. 



bb — Barometer change: See Code Table XI. Amount of barometer change in last 3 hours. Example: "Fall of 0.12 

 inch" — code figures 20. • 



HOURS OF REGULAR OBSERVATIONS 



11. Eegular observations will be taken twice daily, at 0000 G. M. T. and 1200 G. M. T. 

 For instructions regarding special observations, see paragraph 22. 



INSTRUCTIONS FOR RECORDING AND CODING OBSERVATIONS 



12. Enter in column (d) of Form 1210 — Marine, the observation as taken and in column (e) the appropriate 

 code number. 



13. When data are not available or are omitted for any other reason, use an X in column (e) in place of 

 each code figure so omitted and include in radiogram. 



14. It will be necessary for the observer to refer to code tables, as indicated, to obtain the proper code 

 number for most of the data. The code tables appear on pages 6 to 14, inclusive. 



15. An example of Form 1210 — Marine, with an observation recorded and coded thereon appears on page 4. 

 This example also includes Supplemental Data, index 6. 



16. Prepare Form 1210 — Marine, in duplicate. Retain carbon copy for ship's file and mail original as 

 directed in paragraph 21. 



Number Forms 1210 — Marine consecutively, beginning with the first observation of the year. Begin new 

 series each calendar year. 



PREPARATION OF RADIOGRAMS 



17. After the observation is recorded and coded on Form 1210 — Marine, prepare the radio message on 

 Form 1204, in duplicate, and file the original immediately with the radio operator, addressing the message 

 according to instructions given to each individual ship. Retain duplicate and mail according to instructions 

 contained in paragraph 21. 



18. When the ship is in certain designated areas it may be desired that the coded radiograms will be sent 

 elsewhere than to the United States Weather Bureau. When this is desired special arrangements will be made 

 in writing with the ship concerned, and information furnished as to the exact address to be used. 



19. Examples of Form 1204 with coded groups will be found on page 5. 



20. Make the serial number on Form 1204 correspond with the serial number of Form 1210 — Marine 

 from which the radiogram was prepared. 



