Table 1 1 2. 

 INTERNATIONAL METEOROLOGICAL SYMBOLS. 



The International Meteorological Symbols were adopted at the Vienna meteoro- 

 logical congress of 1873. A few additions and modifications have been made at 

 subsequent international meteorological meetings. The forms of these symbols are 

 more or less flexible. Those shown in the accompanying table are the forms which 

 have generally been used in the United States. The principal variants found in the 

 meteorological publications of the different countries are given in the Monthly 

 Weather Revkiv (Wash., D. C), May, 1916, p. 268. 



Exponents. — An exponent added to a symbol indicates the degree of intensity, 

 ranging from ° weak (light, etc.) to ' strong (heavy, etc.). Thus, ®°, light rain; 

 ©', heavy rain. German and French observers use the exponent ^ to denote medium 

 intensity, in accordance with the German and French versions of the report of the 

 Vienna congress, and the German editions of the Codex. The English version of the 

 above-mentioned report and the English edition of the Codex provide for the use of 

 only two exponents, ° and '; hence in English-speaking countries the omission of the 

 exponent indicates medium intensity. 



Time of occurrence. — When hours of occurrence are added to symbols, the abbre- 

 viation a is used for a. m., and p for p. m. Thus, O loa — 4p denotes " rain from 

 10 a. m. to 4 p. m." 12a ^ noon ; i2p ^ midnight. The abbreviation n means " during 

 night." Stations taking tri-daily observations may use a to mean between the first 

 and second observation; p, between the second and third; and n, between the third 

 and the first. 



For further information concerning the International Symbols and other meteoro- 

 logical symbols, see " Meteorological Symbols," by C. Fitzhugh Talman, Monthly 

 Weather Revieiv (Wash., D. C), May, 1916, pp. 265-274. 



Smithsonian Tables. 



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