THE SMITHSONIAN INSTITUTION. 239 



publication. This work was commenced at the close of 1851, and 

 has been prosecuted with considerable vigor during the past year. It 

 was given by me in charge to Mr. Lorin Blodget, of Western New 

 York, who has engaged in the work with much ardor, has devoted to 

 it his whole time and attention, and has evinced an, unusual degree of 

 talent for investigations of this character. 



The results which have thus far been obtained are of interest to the 

 science of meteorology, and valuable to the practical arts of life. The 

 following is a descriptive list of the deductions presented in a tabular 

 form : 



Temperature Tables. 



1. Tables of general mean temperature for a series of years, em- 



bracing a summary of the annual means for the years 1849, 

 1850, 1851, and 1852, with a general summary of reliable obser- 

 vations of mean temperature on the North American continent. 



2. Tables of mean temperature for each month, season, and year, for 



1849, 1S50, 1S51, and 1S52, embracing 273 stations in 1S49; 284 

 in 1850 ; 300 in 1851 ; and 396 in 1852. - 



3. Tables of mean temperature at each observed hour for the same 



periods and the same stations. 



4. Tables of the monthly extremes of temperature, with the range 



above and below the monthly mean, for the same periods and the 

 same stations. 



5. Collection of tables of temperature at different stations, observed 



for a series of years. 



6. Miscellaneous tables of temperature^ not conforming entirely to either 



of the above divisions. 



The first class of tables embraces six hundred and seventy stations, 

 distributed over the entire continent, from the WesJ Indies and Mexico 

 to the Polar seas. , 



The second class has a more limited range, and is generally confined 

 to the United States and its territories, as observed by the military sys- 

 tem, and that of the Smithsonian Institution, with a few stations in 

 Canada and the British possessions on this continent. 



The third class of tables is nearly the same in extent with the pre- 

 ceding, and for three complete years, viz : 1S50, 1851, and 1S52. 



The fourth class is of the same extent and time. 



The fifth is a climatic arrangement of tables from various stations 

 extending in continuous series over periods varying from five to sixty 

 years. 



Tables of Precipitation. 



1. Tables of distribution of precipitation in rain and melted snow for 



each month, season, and year, for 1S49, 1850, 1851, and 1S52. 



2. General tables of precipitation for a series of years, containing the 



results of the preceding tables, with a general summary of all 

 reliable and accessible observation of fall of rain on the North 

 American continent. These tables 'give results from about four 

 hundred stations, principally in the United States, its Territories, 

 and the West Indies. 



