APPENDIX II. GREENWICH MEAN NOON OBSERVATIONS 
Explanation of abbreviations, symbols, and numbers for meteorological results in table 76. Results 
were reported on Weather Bureau Forms according to “Instructions to marine observers--United States 
Weather Bureau. The data include: (1) wind direction -- “‘true;’’ (2) force according to Beaufort Scale; 
(3) temperature in screen from Assman Aspirated Psychrometer; (4) sea-surface bucket observations; 
(5) state of sky--Beaufort Scale. 
METEOROLOGICAL SYMBOLS 
Letters describe conditions at actual time of observation (Beaufort Scale) 
Upper Atmosphere Lower Atmosphere Precipitation 
b blue sky v visibility (exceptionally clear) d drizzling 
ce cloudy sky (detached clouds) z haze Pp passing showers 
© overcast sky m mist r rain 
f fog r heavy rain 
Electric Phenomena r very heavy rain 
1 lightning Wind h hail 
t thunder q squally 
SYMBOLS 
@ solar halo I€ thunderstorm 
= fog =° mist 
aw gale @ continuous rain (intensity may be indicated by 
< distant lightnings without audible thunder attaching “‘exponents’’ 0 or 2 to the symbols) 
CLOUDS WIND FORCE (Beaufort Scale) 
0 stratus st 0 calm 
1 cirrus ci 1 light airs 
2 cirrostratus cist 2 light breeze 
3 cirrocumulus cicu, 3 gentle breeze 
4 altocumulus acu 4 moderate breeze 
5 altostratus ast 5 fresh breeze 
6 stratocumulus stcu 6 strong breeze 
7 nimbus nb 7 high wind (moderate gale) 
8 cumulus cu 8 gale (fresh gale) 
9 cumulonimbus cunb 9 strong gale 
10 nimbostratus nbst 10 whole gale 
11 storm 
12 hurricane 
SEA 
0 calm Oo SWELL 
1 very smooth 1 
2 smooth sea ile Y) 1 no swell 
3 slight sea 23 2 slight swell 
4 moderate sea 35 3 moderate swell 
= rather rough sea 5- 8 4 rather rough 
6 rough sea 2-12 5 rough 
7 high sea 12-20 6 heavy 
8 very high sea 20-40 7 very heavy 
9 precipitous sea 40 8 abnormal 
* Height of wave, crest to trough, in feet 
81 
