EDITORIAL NOTE 



The data 1921 to 1930 for the land stations, part I, have been 

 arranged for publication alphabetically, first under the grand divisions 

 of the earth as Africa, Asia, Europe, etc., then by countries under 

 each division and finally by stations in each country; except in the 

 case of Australia, Africa and the Indian Ocean, where it was found 

 more practical to arrange the stations alphabetically under the larger 

 divisions. In each country the stations giving only rainfall data ap- 

 pear in alphabetical order after the main tables giving two or three 

 elements. 



The grand divisions and the countries are given under their English 

 names, but the names of the stations have been taken as nearly as 

 possible to accord with the spelling used in the countries where they 

 are located, and the English equivalent is given in parentheses. 



The units used are those of the countries where the observations 

 were made, and are given as they were received. 



Owing to the diversity of units used, and to the fact that explana- 

 tion of the methods and the hours of observation were best arranged 

 by countries, it was not considered feasible to publish the data by 

 io° squares of latitude and longitude, as is done in the Reseau Mon- 

 dial. An index of the stations according to the Reseau Mondial 

 system is provided at the end of the publication. 



The material published has been collected, in so far as possible, 

 from official sources responsible for the observations. In addition a 

 large part of the data has been checked against neighboring stations 

 by the various collectors, in order to eliminate errors which easily 

 creep in when copying so large a mass of material. Many such errors 

 were found and corrected by correspondence. In addition, small 

 breaks in the continuity of the records were disclosed, and some of 

 these were corrected by correspondence with the bureaus and offices 

 responsible for the records. The causes of others could not be found, 

 and they were left without change. 



The totals of precipitation are understood to include all forms of 

 condensed moisture ; as rain, snow, sleet, hail, etc. The snow, sleet, 

 hail are given in their equivalents of water by melting, weighing or 

 estimating. In the tropics, the precipitation is chiefly rainfall, in tem- 

 perate latitudes it is rain and snow, and in the polar regions chiefly 

 snow. 



